HomeMy WebLinkAboutPZ Packet 7-26-10NOTICE OF MEETING
The City of Lake Elmo
Planning Commission will conduct a meeting on
Monday, July 26, 2010, at 7:00 p.m.
1. Pledge of Allegiance
2. Approve Agenda
3. Approve Minutes
a. None.
4. Public Hearings
a. None
5. Business Items
a. Comprehensive Plan — Urban (Sewered) Area Density Analysis Discussion.
b. County SSTS Ordinance (Subsurface Sewage Treatment System Regulations)
Discussion.
6. Updates (Verbal)
a. City Council;
i. July 13, 2010 Workshop: Village Area Plaiming, Home Occupation
Ordinance, and Senior Living /Farm School Development
ii. July 20, 2010 Meeting: Administrative Fine Ordinance, Home
Occupation Ordinance, Senior Living /Farm School Development
b. Staff Updates
c. Commission Concerns
7. Adjourn
Planning Commission
Date: 7/26/10
Business Item
Item: 5a
ITEM: Comprehensive Plan —Urban (Sewered) Area Density Analysis Discussion
REQUESTED BY: Planning Department
SUBMITTED BY: Kelli Matzek, City Planner
REVIEWED BY: Danielle Bailey, Planning Intern
SUMMARY AND ACTION REQUESTED:
The Planning Commission is being asked to review the housing and employment projections from
the Lake Elmo Comprehensive Plan and to specifically discuss the analysis and resulting figures
as they relate to the City's future sewered development areas. Staff has attempted to analyze the
land areas available for development, the housing and employment counts required, and the
corresponding densities for the two areas in the city guided for future sewered development — the
Village Area and South of 10th Street. Staff found a few discrepancies and conflicting data in
utilizing various guiding documents and therefore, some assumptions were made in the attached
analysis. The attached charts and maps contain a significant amount of information that will be
more thoroughly discussed at the Planning Commission meeting on July 26th.
REVIEW OF COMP PLAN PROJECTIONS AND ANALYSIS
1 -94 to 10th Street
One of the attached charts developed by Staff provides information on the acres available for
both residential and non - residential development for the future sewered areas South of 10"
Street. This analysis found that almost 50 acres of land guided for residential development is in a
floodplain and is unbuildable. However, staff also found that a parcel guided for Public Facilities
may be more aptly developed for sewered residential housing and would therefore accommodate
the loss of land to floodplains. Staff found the inclusion of this parcel and resulting calculation to
be close to that identified in the Comprehensive Plan.
The same chart analyzes the proposed future sewered non - residential development in the 1 -94
corridor. Staff found the numbers to be lower than that identified in the Comprehensive Plan —
however, the number of sewered employees (the unit used in the land use chapter of the Comp
Plan) is inclusive of both the 1 -94 corridor and the Village Area and is identified as "Total Sew.
Employees." Further study is needed by staff to evaluate the employment calculations in the
Village Area to ensure this requirement could be met.
Staff has some concern with meeting the employment requirements as outlined in the
Memorandum of Understanding (MOU). The density requirement for employment in the 1 -94
corridor is 40 employees per acre for both the area guided as Business Park and Limited
Business. This high density may be difficult to achieve as the idea of a corporate campus at the
corner of Manning and 1 -94 may no longer be supported by the market. As a real world example,
staff provided a map showing some examples in the Lake Elmo Eagle Point Business Park
development of the number of employees per acre. This may help to visualize what 40
employees per acre may look like in the future.
Village Area
As mentioned earlier in this report, staff is providing a chart showing some draft numbers of the
employment calculations in the Village Area. Staff will need additional time to further refine and
analyze the numbers as there are some significant assumptions made when converting from
Residential Equivalent Units (REC) to employees.
Additionally, a chart is provided with an analysis of the future residential development of the
Village Area. The majority of the discrepancies in the guiding documents (2006 Comprehensive
Plan, Village Area Master Plan, Village Area AUAR, and a letter dated 12 -3 -07 from the previous
City Attorney) is in the interpretation of the number of future residential housing units that are
required. Staff will go through some of the discrepancies during the meeting, but the focus of the
discussion should not be on the discrepancies, but instead how the city would like to move
forward.
As discussed during the rural density discussion in June, the overestimate of the current housing
in the Village also creates some imprecise calculations and adds to the discrepancies mentioned
above. A study conducted in 2007 showed that there were 194 housing units within the Village
area, which is 306 less (500 assumed) than would hook up to the regional sewer in 2030
according to the Comprehensive Plan.
The problem with attempting to adjust the numbers used in the Comprehensive Plan is that the
306 Village units either need to be added to the unsewered development areas or the sewered
development areas in order for the overall housing unit and population projections to reach the
respective targets of 8,727 and 24,000 set in the Comprehensive Plan.
Penalties
In addition, the Comprehensive Plan does state there are penalties to the city if certain
development does not occur at the assigned timetable. Staff has been working with the
Metropolitan Council to receive an extension to the table, but the wording in this chapter may
need to be revised due to the downturn in the market as well.
ADDITIONAL INFORMATION:
• Given the complex nature of this information, Staff is planning to take time with the Planning
Commission to review and discuss attached charts and maps at the July 26th meeting.
STAFF RECOMMENDATION:
The Planning Commission is not being asked to take any specific action at this time. Staff is
seeking feedback concerning the methodology used to achieve the scenarios described above,
and any additional comments regarding the Comprehensive Plan's household and employment
projections.
ORDER OF BUSINESS:
- Introduction ..... ...............................
- Report by staff ., ....... - ....................
- Discussion by the Commission .....
ATTACHMENTS:
............................ Kyle Klatt, Planning Director
..... ............................... Kelli Matzek, City Planner
.......... .... I ........... .. Chair & Commission Members
1. 1 -94 Area Analysis Chart
2. Future Land Use Map
3. Existing Eagle Point Business Park Map
4. Village Area Residential Analysis Chart
5. Ltr. Attorney Filla 12 -3 -07
6. Comprehensive Plan Village Area Future Land Use Map
7. Village Area Employee Analysis Chart
8. Village Area '' /z Mile Radius Map
9. Memorandum of Understanding (MOU)
10. Excerpts from 2006 Lake Elmo Comprehensive Plan
11. Excerpts from Lake Elmo Village Area AUAR
12. Village Area Master Plan Map
1-94 Area Analysis ---Future Sewered Residential and Non-Residential
Land Area Guided for SRD:
Jed in the Land Use Map)
tially buildable area guided t
Analysis - Residential
Sewered Residential (S of
in R -3 (Cimarron)
Partially guided
tided SRD3.5 (pg III -7)
-- I
olds Other Sewered (pg III -17)
is a separate line item in the chart and is not included in this
14 acre parcel guided PF unintentionally
floodplain and PF guided properties
calculated by stall densities from Comp Plan used
miiaiysra - rvvn- mesiaential:
LB (Future sewer - 40 Employees /Acre)
BP (Future sewer--4-0-
ewer - 40 Employees /Acre)
4RY-- -
calculated by staff, densities from Comp Plan used
LB Future Sewer
BP - Sewe_red (pg ll
Existinq BP (sewer(
from Comp Plan
New Sewered Employees (MOU)
(The sewered employee counts calculated here do not include Village Area
'As identified in the Comp Plan
Acreages and densities calculated in Comp Plan
SRD3.5 Sewered Residential Development 3.5 unit Density
LB - Limited Business
BP - Business Park
1,110.82
49.1
35.87
1,025.85
Acres e
1,025.85 1 3.5
5003
1
ME
Acres Di
16.1 40
241 40
257.1
241 40
121 + -
therefore the numbers do not match calculations
1]
residential and non - residential analysis for "'a '_94 area
done utilizing information from the 2006 Comprehensive
the Village Area AUAR and the Village Area Master
Some conflicting data was found among the sources
assumptions were made by staff in the creation of this
FUTURE LAND USE
Lake Elmo Comprehensive Plan 2005 - 2030
Limitation Of Liability Map Dale: Janu2ry31,2006
n.SCx,:,:enl,aro181f^e ' yrewrGaOmap Cr WneydM rsmr
tanieon'eom`;a °b.:umae . mm�an<Ir.<:rGa C.<mw B, TKDA o eo . oo z4oa a.eao
Feel
and Use
C RED
1'f PF ....... ROW
RAD-PAS DU /We i, w,T
RAO 2MM.e SR
,.'ii URD- Cimaemn
SRO - 3500 /AVe
_d l8 Fu(um 56wC1- Aa EmpIOYCeeIACm
1.. l8 NCmSewCr
w
hr
8
E
5
....u. .r.am
C
..na
FUTURE LAND USE
Lake Elmo Comprehensive Plan 2005 - 2030
Limitation Of Liability Map Dale: Janu2ry31,2006
n.SCx,:,:enl,aro181f^e ' yrewrGaOmap Cr WneydM rsmr
tanieon'eom`;a °b.:umae . mm�an<Ir.<:rGa C.<mw B, TKDA o eo . oo z4oa a.eao
Feel
and Use
C RED
1'f PF ....... ROW
RAD-PAS DU /We i, w,T
RAO 2MM.e SR
,.'ii URD- Cimaemn
SRO - 3500 /AVe
_d l8 Fu(um 56wC1- Aa EmpIOYCeeIACm
1.. l8 NCmSewCr
Existing Eagle Point Business Park
& Medium
ig over Retail
SF
223.4
Village Area Residential Analysis
364
7
23.4'
1.5 - 2.5
(avg. 446.5)
411 - 625 (avg. 518)
Village Master Plan
1.5
8
10 - 15 (avg.
Comprehensive Plan Scenario
7.2'
2.5
18
12 - 15 (avg.
13.5)
3411
8
278
2.58 - 342 (avg. 300)
1
i
106
GUAR Information on Villa e
9
_
Master Plan - Scenario: 600 Units
[5.5]
32
280
Comprehensive Plan - 906
p Units (AUAR Analysis)
4161
[0.6 - 0,9]
-
Lot Type Acres Density
Units
4
58
Acres !; Densit
Units
Exlstln Oid Villa e Cit Fabric
9 g -Y
-
Large & Medium 223.4 0.98
218
VR/HD
7_ 14.6
102
Open Water -
7Land
Large 5.3 1 0.8
4
VR/LD
- 77 4.4
339
Existing R -O -W
- - -
Medium 7.2 1 3
9
VR MU /MD
45 10.3
465
Potential Future Redevelopment
- _ _ - -
-
;A
- _ - _
(Existing Dev. Parcels)
Townhouse 34 7 3.9
136
New Mixed Use Dev -
- 73
- - -i
- 1
Twinhome 21.2 2.5
52
SUMMARY
- - - - - - 129 7.0
906 -
New Civic /Institutional
16.5
- - -
- 5-0.5
Apt/Condo 1 5 � 2.7
137
i 1
New Residential Dew.
--
308.6
--
1
-- - -- - -- "- ._l
Housing over Retail 43.6 0.4
__ l-
16
Comprehensive Plan Text
P (pg III -4 to 5)
Buffer Zone, New & Existing
-- - -- --
Parks, Horse Farm, Existing Old
I-
Village City abric (Open Space) Y ( P P -_)
-
532.2
i
- - _
Small SF 1 14.5 1.9
-
28
,Acres Densit
�
Units
1274.5
-
VR /HD
7' 14.15
101,
-- -
SUMMARY 1 400.4 1.5
600
VR /LD
-
77 3 -4.4
231 -339
-
-
'(Assumed uniform reduction in housing type)
- -
VR MU /MD
-
- 45 5-6
225 - 270
Vi llage Area Master Plan Designation
Master Plan - Scenario: 1000 Units
SUMMARY
- '
129 4.3 - 5.5
-
557 7 - 710
& Medium
ig over Retail
SF
1227
I no residential analysis for the Village Area was done utilizing information from the 2006 Comprehensive Plan, tf
'Village Area AUAR, the Village Area Master Plan, and a letter written by former City Attorney Jerome Filla dated
.December 3, 2007. Some conflicting data was found among the sources and assumptions were made by staff in
the creation of this document
& Medium 1
223.4
JJJ - JJu
364
7
23.4'
1.5 - 2.5
(avg. 446.5)
411 - 625 (avg. 518)
5.3
1.5
8
10 - 15 (avg.
12.5)
7.2'
2.5
18
12 - 15 (avg.
13.5)
3411
8
278
2.58 - 342 (avg. 300)
21.2
5
--
106
45 - 60 (avg.
52.5)_
50.5�
[5.5]
32
280
IARY I
4161
[0.6 - 0,9]
-
25 - 40 (avg.
32.5)_
14.5;
4
58
77 - 100 (avq.
88.5)
1227
I no residential analysis for the Village Area was done utilizing information from the 2006 Comprehensive Plan, tf
'Village Area AUAR, the Village Area Master Plan, and a letter written by former City Attorney Jerome Filla dated
.December 3, 2007. Some conflicting data was found among the sources and assumptions were made by staff in
the creation of this document
& Medium 1
223.4
1.6
364
7
5.3 -
-1.3
- -7-
m
7.2
21
15
louse
34.7
6.5
227
M me
21 .2
4.1
86
m do
50.5
4.5
22 8
g over Retaill
43.6
0.6
26
SF 1
14.5
32
47
IARY I
400.4
2.5
100C
ad uniform reduction in housino tvoe)
& Medium 1
223.4
2.6
1 583
7
5.3
1.9
1 10
m
1 -
32
1 - 23
louse
-7,2
34.7 1
10.5
363
Dme
21.2
6.5
_
138
)ndo
50.5 i
7.2
365
L
ig over Retail
43.6
1.0
42
SF
14.5
+- 76
L
-5.2
1ARY
400.4
4.0
1600
ad uniform increase in housing type)
Plan calls for up to 100
l urnprenensive Tian Attorney Analysis (see bottom left)
IAcres
!Density
Units
7
1_4.5
101.5
77
0 .45
34.65
-
1D 86
5 -6
-
1430_ -516
43
0.45
19.5
717
0.45
322.65
i
2Y 930
5.3 - 5.9
1 909 - 995
density was calculated using transfer of density as identified in the Comprehensive
id therefore the entire land area was not used -)
HD - Village Residential High Density
LD - Village Residential Low Density
MU /MD - Village Residential Mixed Use /Medium
- - -
P/S_- Village Residential Pub6o and Semi - Publi-
c
G/B - Village Residential Green Belt
irren E. Peterson PEERS N
ome P. Fills i
Iniel Witt Pram 7i- -�7-1 p ,� BEi��yt, ,c n T T
enn A. Bergman �1'++l��,f"��,/1 111`(\..7_11 \V /lf 1L�111 \VI
in Michael Miller e e c
chael T Oberle
even H. Bruns -
ul W. Fahning°
ma R. Ortiz
iy K. L. Schmidt
n I. Rust
ed M. Goerlitz
December 3, 2007
Mayor Dean Johnston and
Lake Elmo City Councilmembers
City of Lake Elmo
3800 Laverne Ave. North
Lake Elmo, MN 55042
Re: Sewered Housing Units
Old Village Area
Dear Mayor Johnston and Members of the City Council:
Suite 800
55 East Fifth Street
St. Paul, MN 55101 -1718
(651) 291 -8955
(651) 228 -1753 facsimile
www.pfb- pa.com
(651)290 -6907
ifilla(@Pfb- oa.com
In 2004, the Minnesota Supreme Court determined that the Metropolitan Council
had the statutory authority to require the City to modify its proposed Comprehensive
Plan in the manner provided by Metropolitan Council Resolution No. 2003 -10. This
particular Metropolitan Council Resolution effectively incorporated a list of nine (9)
required modifications, including a requirement that there would be development to
accommodate 7,850 Residential Equivalent Units (RFC's) of regional sewer
capacity. All City Councilmembers opposed this level of development and asked the
Metropolitan Council if it would be willing to negotiate some other solution. The
negotiation resulted in the Memorandum of Understanding.
The Memorandum of Understanding was intended to provide guidance to the City as
it began the task of revising the Comprehensive Plan draft that had been rejected by
the Metropolitan Council. The Memorandum of Understanding mandates that the
City achieve certain development goals by 2030 (Population- 24,000; residential
REC's- 5,200; and employment REC's- 1,400), but it permits the City to use its
discretion in determining how to achieve the 2030 development goals. The specific
manner in which the City chose to exercise its discretion is reflected in the
Comprehensive Plan that was approved by the City and by the Metropolitan Council,
and in the official control which the City has and will adopt to implement the
policies of the Comprehensive Plan.
In regard to the Old Village (both existing and new), the Comprehensive Plan
identifies the number of sewered housing units in two (2) ways. First, it specifically
states that there will be 1,100 sewered housing units in the Old Village by 2030
(Comprehensive Plan III -17). The City Engineer advises me there are 194 current
•AL50 ADM MED IN WISCONSIN
December 3, 2007
Page 2
housing units in the Old Village. By subtracting current housing units from the
projected housing units, the result is 906 new housing units.
Secondly, the Comprehensive Plan indirectly estimates the possible number of new
housing units by adopting zoning categories for the Old Village (Comprehensive Plan
III -3 through III -5); by specifying permissible densities within zoning categories for
the Old Village (Comprehensive Plan III -3 through III -5); and by identifying the
number of acres available for development within various zoning categories
(Comprehensive Plan III -7).
Zone
Units /Acre
Acres
Max. Units
1. VR/HD
14.5
7
101.5
2. VR/LD
0.45
77
34.65
3. VR MU /MD
5 -6
86
430 -516
4. VR P/S
0.45
43
19.5
5. VR/GB
0.45
717
322.65
The above calculations indicate that there could be 909 -995 new housing units to
the Village area in addition to the existing 194.
If you have any questions please contact me.
Very truly yours,
/s/
Jerome P. Filla
JPF /jmt
F:\usen\Jessica\jeny\LE\CouespondenceVohnston Ltr Idoc
1
1
1
1
i
1
1
1
1
1
1
1
1
1
EK"A
PRELIMINARY VILLAGE AREA
FUTURE LAND USE
Lake Elmo Comprehensive Plan 2005 - 2030
LIMItation of LIAbIfity Map OaW JsnuaryJl,2006
TKDA
z
a i �11
Legend
Land Use
VR-HD
=J VR-MUIMD
VR-LD
IBM VR-GS
Im VR-Pls
N
ro
ID
10
0-
0 CL
I m E
Ij
cc
mio
a) a�
(D a)
a)j
>
>11
>
10
'a
0
IL
CL
m EjE
CLI CL
E E
E
0100 CL
q
0
a)
m
p
CLJUJ W
ujiuj
ui
E
LLI
r 0
4) �
a)
m
00
0 It
:001co
_7
(0
010
0
—
jc�
I 10
E
CL
E
LU
i ILU
4z
I4
GI
0 1 C)
1 Ui Lli
1
jl� I Q�
LU
0
u
E E
E)
I
I a>
WIN
(D 0,
I
LU
E
UJ 0
U
I
0
E E
Lli I li
CL
E
E
0,0
w
Z'O
W
-T
.2
I
E� 0
0 1
s
1 0
0
j
ZZ E
LI
S
C
0
C)
E
T -
0
'UI 1
m
E
ws
WI
(L
cil
4)
CL
m)
01" 0) o a)
a) 10
10
LI
RIcoI�
a
Q� (L
j
I
W
0
•
l(D (DI—xi
z Z, Lki E
E
c
0
E
m co
z
M
O
01
w :�_5
E va! 76 E
'6 '6
IN
m
a
I
x
> � Lli
0) o
w I
z
$F+? ~ 3G
MEMORANDUM OF UNDERSTANDING
Lake Elmo / Metropolitan Council
Outline of criteria to be considered in preparation of City Comprehensive Plan
The following criteria were developed as the result of discussions among representatives of the City
of Lake Elmo ( "City") and the Metropolitan Council ( "Council'). These criteria are intended to
provide guidance to the City and to the Met Council as Lake Elmo modifies its local comprehensive
plan to ensure conformity with metropolitan system plans as required by state law.
I. The City of Lake Elmo will commit to 6,500 new Residential Equivalent Units ( "RECs ") of
Regional Sewer service by the year 2030. The City will commit to a city -wide population of
24,000 by the year 2030. Performance measures for this agreement will be total population and
total utilized RECs in Lake Elmo.
Note: The tern "REC" shall be defined in Lake Elmo as one residential connection and /or the
equivalent of 10 employees for new business operations.
2. The City will implement the population, employment, and RECs in the following manner.
Year
2000
2010
2020
2030
Population
6,863
TBD
TBD
24,000
Residential RECs
0
TBD
TBD
5,200
Employment RECs
100
TBD
TBD
1,400
Total RECs
100
TBD
TBD
6,600
3. The City will determine the types of housing and businesses to be developed and will meet or
exceed an average residential density of 3 units per acre or a non - residential density of 40
employees per acre in urban (sewered) areas in the area south of 10`h Street.
4. The City will plan for 1,300 new RECs (20% of 6,500) to be used for sewered employment.
5. The City will plan for Regional Sewer service to be provided in the southwest comer of Lake
Elmo via the WONE Interceptor, and at Lake Elmo Avenue via the Cottage Grove Interceptor.
Sewer capacity will be provided to meet the needs as specified in paragraph 2. It is anticipated
at this time that design flows for the Regional Sewer service provided to the City will be made
available as follows:
RECs MGD
To WONE Interceptor - Metro Plait 1,825 0.50
(estimated construction completion: Dec. 2006)
To Cottage Grove Interceptor - Eagles Point Plant
Phase I (estimated construction completion: Dec. 2007) 1,825 0.50
Phase 11 (estimated construction completion: Dec. 2010) 4,675 1.28
Total 8,325 2.28
Page I of 2 Pages
6. The City of Lake Elmo will achieve a city -wide population of 24,000 by 2030. All population
will be counted. Lake Elmo will use 6,600 RECs by 2030. All RECs used will be counted.
Should the City determine to extend Regional Sewer service to the existing Cimarron
manufactured housing neighborhood (500 RECs), existing Old Village housing (up to 500
RECs), and /or new Old Village housing (up to 500 RECs), all utilized RECs shall be counted
toward the expected community totals. Up to 1,000 RECs may be used in the Old Village area
of Lake Elmo. It is understood that the average density of the aforementioned Old Village units
shall be at least 3 units per acre.
The City will complete its required plan modifications by April 15, 2005 and submit its plan to
adjacent communities for review by that time. This will allow time for the City to complete its
local planning and review processes and submit its required plan modifications to the Council
on for before June 15, 2005 and prior to the expiration of the nine -month plan modification
period specified in state law.
9. The City's comprehensive plan shall be flexible enough to allow for possible limited post 2030
development, redevelopment, or environmental mitigation utilizing any Regional Sewer
capacity (see paragraph 5) that may remain post 2030.
10. The signatories will present and recommend these guidelines to their respective governing
bodies for consideration with the understanding that: (a) the adoption of a modified
comprehensive plan ultimately is the responsibility of the full Lake Elmo City Council; and (b)
the full governing body of the Metropolitan Council ultimately is responsible for reviewing the
plan submitted by the City and determining whether the modified comprehensive plan conforms
with metropolitan system plans.
half of City`o Lak 1 0:
Dean A. Johnston, Mayor
Date: 2049 —d /— 2
1/27/2005 3:02 PM
On I if etro o Council:
eter Bell, Cha r
Date: 710
Page 2 of 2 Pager
Lake Elmo Comprehensive Plan Chapter 111 - Land Use Plan
Existing
362
BP
Business Park
121
C
Commercial
114
LB
Limited Business
243
PF
Public/Semi-Public Facilities
3450
RAD
Rural Agricultural Density
7020
RED
Residential Estates Density
760
now
Right-of-Way
509
SRD
Single-family Residential Density
1709
URD
Urban Residential Density
169
WAT
Water
1155
TOTAL
15250
ROW
Total Area l Village -Aria South otl0th
45
BP
362
362
C
58
54
1
LB Future sewer
16
16
LB Non-sewer
45
lqC
1658
116
PF
3381
23
122
RAID
5029
74
RAD2
142
RED
691
153
ROW
545
45
161
SRD15
1069
1069
URD
169
169
WAT
'1155
25
VR-l-lD
7
7
VR-LD
77
77
VR-MU/MD
so
86
VR-P/S
43
43
VR-GB
717
717
TOTAL 15,250 1,168 2,152
Relationship to the Regional Development Framework
During the development, review and local adoption of this Land Use Plan the City
Staff, Planning Commission, and City Council reflected repeatedly on the
relationship of the Plan to the 2030 Regional Development Framework and the
Metropolitan Council Draft 2030 Water Resources Management Plan. The details
and amplifications of the 2005 Memorandum of Understanding (hereafter, "2005
MOU") have been incorporated in the Land Use Plan to the extent that such
details and amplification inodify or expand the framework and/or Draft Water
Resources Plan. MOLT takes precedence where there is conflict with the
Framework or Water Resources Plan,
111-7
Lake Elmo Comprehensive Plana Chapter III — Land Use Plan
1. The 2030 population and employment forecasts contained in Appendix A of the
Metropolitan Council 2030 Development Framework — as adjusted in regard to
forecasted persons- per - dwelling unit and the 2005 MO-U.
2. The Regional wastewater flour targets for Lake Elmo front the MetopoIitan
Council Draft 2030 Water Resources Management Plan.
1 Paragraphs #2 and 45 of the City of Lake EhnolMetropolitan Council 2003 iMOU.
4. The City of Lake Elmo Community Facilities and Staffing Report 2002
With respect to Regionally Sewered growth, Paragraph #l5 of the 2005 MOU details the
planned Regional Wastewater capacities available to Lake Ehno as follows:
R C MGD
ToWONE Interceptor Metro Plant 1,825 0 -50
(estimated construction completion: Dec 2006)
To Cottage Grove Interceptor - Eagles Point Plant
Phased (estimated construction completion: Dec. 2007) 1,825 0:50
Phase 11 (estimated construction completion: Dec. 2010) 4,675 1,28
Total 8,325 2.28
As required by the Metropolitan Council "Local planning Handbook,,, the Lake Elmo
Development Staging Platt, in 5 year increments, shall be as follows:
2000 2005 2010 2015 2020 2025 2030
Total Households 2347 2750 3619 5114 6324 7524 8727
Households
Old Village — Sewered 0 0 515 600 600 600 1100
Cimarron — Sewered 0 0 0 0 500 500 500
Other Sewered 0 0 0 1050 1900 2750 3600
Total Population 6x63 7700 9952 14064 18403 21895 24000
Total Sew. Employees 10051 1000 1000 3800 5950 8800 13000
Total Employment 16+36 1-943 2250 5050 7200 10050 14000
The foregoing projections of Sewered and unseweted dwelling units, population and
employment shall be reviewed by the City at 5 year increments utilizing the data of tire
US Census Bureau for even year increments and the official estimates of the
Metropolitan Council foi odd year increments — when such data becomes available, to the
Public. If it is determined that the actual production of dwelling units, population and
employment within the City is not equal to or greater than the foregoing projections, the
City. with the cooperation and concurrence of the Metropolitan Council, will
development measures to overcomeany shortfalls during the ensuing year period.
The City will adopt legal provisions to maintain this Staging Plan that may include a
limitation on annual number of lots approved for platting, m nibe�of building permits
issued, geographic extent of allowable development, or some combination of these of
other suitable provisions. Such staging provisions shall provide for acceleration of the
Ill - 17
Lake Elmo Cornprehensive Plan
-
Chapter V1 — Wastewater Facilities
1. Community Forecast of Households and Employment
Served by Regional Sewer Service (SAC Units)
Year
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
0
280
560
840
1120
1120
1120
1120
1120
Old Village
0
125
250
320
390
530
600
600
600
600
600
600
600
600
S of 10th
0
0
0
0
0
0
0
0
0
0
100
270
440
610
0
100
0
100
125
152
0
152
250
2D4
0
204
320
256
0
256
390
308
0
308
460
360
0
360
530
384
0
384
880
408
0
408
1160
432
0
432
1440
456
0
456
1720
480
0
480
1820
480
64
1990
480
128
2160
480
192
2330
480
256
2021
1120
600
950
2670
480
384
2022
1120
600
1120
2840
480
448
2023
1120
600
1290
3010
480
512
2024
1120
600
1460
3180
480
576
2025
1120
600
1630
3350
480
640
21330'`
1120
600
2480
4200
480
920
2. Sanitary Sewer Mars Map.
The Staging Plan Man shows sewer service staging in 5 year increments and
future land use.
VI -2
544
608
672
736
800
864
928
992
1056
1120
1400
Lake Elmo Village Area Final AUAR May 5, 2009 Page 4
the potential development opportunities associated with each land use category included in the
composite land use map.
Table 6 -1
Village Master Plan Composite T.nnd Tice Man _ Pnta. *i.i
Land Use Category
Acres
Potential Development Opportunities
Potential Future Redevelopment
44.5
Apartments /Condos, Neighborhood Retail, Housing
(Existing Developed Parcels)
Over Retail, Office
New Mixed Use Development
72.5
Apartments /Condos, Townhomes, and Small Lot Single
Family. Commercial and Office Node (along TH 5 near
39th St.)
New Civic /Institutional
16.5
City Hall, Community Campus (family service center,
Development
library, wellness center, art center), New schools
New Residential Development
308.6
Variety of single family detached lot sizes, Townhomes
Existing Old Village City Fabric
154.2
Represents the portions of the Village that axe not
(Built Area)
identified for future redevelopment
Buffer Zone /Open Space,
532.2
Active and passive recreational opportunities
New Parks /Open Space,
Existing Parks /Open Space,
Horse Farm, and Existing Old
Village City Fabric (Open Space)
Open Water
62.0
Active and passive recreational opportunities
Right of Way (existing)
84.0
Road maintenance and improvement projects
The only difference between the three scenarios based on the Village Master Plan is in the
number of residential housing units (Scenarios A — 600 residential units, B — 1,000 residential
units, and C — 1,600 residential units). All other development assumptions are the same between
the scenarios (e.g., parks, open space, commercial, office, and institutional uses). A development
scenario description is included in Table 6 -2 and displayed on Figure 6 -1.
Lake Elmo Village Area Final AUAR May 5, 2009 Page 5
Table 6 -2
Village Master Plan Develonment Scenarios Description (Scenarios A. B. and Cl
Composite Land Use Plan
Scenario A
Scenario B
Scenario C
Source:
Parks and Open Space
47%
47%
47%
Village Master Plan
(current and future)
prepared by Engstrom and
Close Landscape
Architects
Existing Village Built Area
14%
14%
14%
Village Master Plan
New
7%
7%
7%
Village Master Plan
Commercial/Institutional
• New Commercial
300,000 ft'
300,000 ftz
300,000 ftz
Close Landscape
Architects
• New Office
150,000 ftz
150,000 ft'
150,000 ftz
Close Landscape
Architects
• New Institutional
200,000 ft2
200,000 ftc
200,000 ftz
Close Landscape
Architects
New residential
32%
32%
32%
Village Master Plan
(A) Comp plan
• New Housing
600 units (B)
1,000 units (B)
1,600 units (B)
(B) Village Master Plan
COMPREHENSIVE PLAN' — AUAR SCENARIO D
This future land use plan has been effectively replaced by the vision presented in the Village Master Plan
for future development of the Village regardless of how many new housing units are part of the future
development. Nevertheless, under the EQB's AUAR regulations, the city's comprehensive plan is a
required scenario to be studied. The city attorney has determined the number of new housing units
required in the comprehensive plan for the Village is 906 new units due to the number of actual existing
housing units (Appendix D). This number is required to be used in evaluating the comprehensive plan
impacts. However, the implementation of any new development scenario based on the Village Master
Plan will require amending the comprehensive plan.
The city's adopted future land use plan is shown in Figure 6 -2. This plan provides for low density
housing located east of Reid Park between 30r' Street and the railroad tracks, a high density residential
area located at the former lumberyard site, medium density and mixed use centered along Stillwater Blvd
(TH 5), public space east of fire new residential areas, and a green belt surrounding the existing and
proposed built portions of the village. Table 6 -3 includes a more detailed description of Scenario D.
Lake Elmo Village Area Final AUAR May 5, 2009 Paqe 6
Table 6 -3
Comprehensive Plan Scenario Description (Scenario D)
Village Future Land Use Designation
Acres
Housing.Units Commercial/Office (ft') Institutional (fl')
Village Residential High Density (VR /I-ID)
7
102
Village Residential Low Density (VR/LD)
77
339 -
Village Residential Mixed Use/Medium Density (VR MU /MD)
45
465 450,000
Village Residential Mixed Use /Medium Density (VR MU /MD)
41
-
Village Residential Public /Semi Public (VR P /S)
43
- - 200,000
Village Residential Green Belt (VR GB)
717
Open Water
62
Right of Way
84
No designation (existing Village Area)
199
Total
1,275
906 450,000 200,000
Refers to the "white" areas on the Village Area Future Land Use Map
DEVELOPMENT SCENARIO COMPARISON
A comparison of the four development scenarios is provided in Table 6-4. The table provides a summary
of the residential units, square feet of non - residential uses, and the percent of the Village that would
accommodate the proposed uses.
Table 6-4
AUAR Development Scenario Comparison
Land Use Type
Scenario A
Scenario B
Scenario C
Secanrio D
Parks and Open Space
47%
47%
47 %
64%
New Residential
32%
32%
32%
11%
New Housing 600 units 1,000 units 1,600 units 906 units
New Commercial /Institutional 7% 7% 7% 7%
• New Commercial
• New Office
300,000 ft2 300,000 ft2
150,000 ft2 150,000 ft2
300,000 ft' 300,000 ft2
150,000 ft2 150,000 ft2
• New Institutional
200,000 ft'
200,000 ft2
200,000 ft'
200,0100 ft'
Existing Village Built Area
14%
14%
14%
18%
. 0 . . . . . . . . . .
Planning Commission
Date: 7/26/10
County SSTS Ordinance Discussion
Business Item
Item: 5b
ITEM: General Discussion Concerning County SSTS Ordinance (Subsurface Sewage
Treatment System Regulations)1
SUBMITTED BY: Kyle Klatt, Planning DirectorM1
aE
REVIEWED BY: Kelli Matzek, City Administrator
SUMMARY AND ACTION REQUESTED:
The Planning Commission is being asked to receive an update from Staff concerning the recently
adopted Subsurface Sewage Treatment System (SSTS) regulations adopted by Washington County. In
accordance with Minnesota Rules, the City must adopt an ordinance that, at a minimum, is as strict as the
new County ordinance within one year from the date of County approval. In this case, the City must
either revise its regulations to either match or exceed the County's regulations by September 23, 2010 or
will otherwise be required to abide by the County's ordinance.
BACKGROUND INFORMATION:
The City of Lake Elmo is unique in Washington County as it is one of only two communities that
administers its own Individual Sewage Treatment Ordinance and does not rely on the County for these
services. In addition, the City's current wastewater regulations would still include several standards that
are more restrictive than the County. Staff is currently reviewing both the County's recently adopted
Ordinance and the City's regulations, and will be providing a verbal update on some of the differences at
the Planning Commission meeting. Some of the provisions that are more restrictive than the County's
regulations include the following:
• Mound systems are not allowed as the first disposal site on any lot. The County's regulations
permit this type of system as a primary system on a lot.
• The City requires sewage tanks shall be pumped or inspected by a city - licensed septic pumper,
or inspected by a state - certified septic inspector every 2 years. The County ordinance specifies
that these inspections can occur on a three -year cycle.
In addition, the City's regulations include provisions related to Community Sewage Treatment (201)
Systems and Alternative Sewage Treatment (Wetland) Systems; a good portion of which deal with the
administration of these systems, which is also somewhat unique amongst other communities in
Washington County.
At this point in time, Staff is still reviewing the City's Ordinances and comparing them to the new County
requirements. It appears that the most logical approach for the City will be to adopt the County ordinance
by reference and either keep or eliminate those provisions that are more restrictive. Staff is seeking any
initial feedback from Planning Commission in advance of preparing a formal ordinance revision for review
at a future meeting. Staff will also be working to identify all of the regulations that the City has adopted
that would remain more restrictive than the County's ordinance.
OTHER INFORAMTION:
Staff from Washington County will be making a presentation to the City Council on August 4, 2010
regarding the County SSTS Ordinance.
The City Code provisions that are applicable to this discussion include Chapter 51, Sections 51.001 —
51.007 and 51.045 — 51.066.
RECOMMENDATION:
Staff is recommending that the Planning Commission conduct a brief discussion on the issues described
above and provide comments and suggestions that can be used to guide future work on the ordinance.
ATTACHMENTS:
1. Letter from Washington County Regarding SSTS Ordinance
2. Washington County Development Code, Chapter 4: SSTS Regulations
Introduction and Presentation by Staff .... ...........................Kyle Klatt, Planning Director
Questions from the Commission .......... ..........................Chair & Commission Members
Planning Commission Discussion.. ............. .. ......................... ....... - ... Chair Facilitates
•
May 10, 2010
City of Lake Elmo
C/O Susan Hoyt
3800 Laverne Avenue North
Lake Elmo MN 55042
COUNTY SSTS ORDINANCE
r.,
F. F.w.': 177p [ s ..� — L
�n
MY i I ztll jti
Cc. (cOC4 i CI I r l?, r, -Pac
Department of Public
Health and Environment
Lowell Johnson
Director
Sue Hedlund
Deputy Director
On September 8, 2009, the Washington County Board of Commissioners passed a resolution
repealing the Washington County Development Code, Chapter Four, Individual Sewage Treatment
System Regulations (Ordinance #128) and adopting the Washington County Development Code,
Chapter Four, Subsurface Sewage Treatment System Regulations (Washington County Ordinance
4179). The effective date of the ordinance is September 23, 2009.
Minnesota Rules, Chapter 7082.0050, Subpart 1, Paragraph B states:
City and township ordinances must be adopted no more than 12 months after adoption of
the county ordinance in which the city or township is located and must comply with the
standards of chapter 7080 to 7083 and must be as strict as the applicable county ordinance.
If CITY /TOWNSHIP NAME has a current septic system ordinance, it must be revised by no later
than September 23, 2010 and be as strict as Washington County Ordinance #179. If
CITY /TOWNSHIP does not currently have a septic system ordinance, you may either adopt an
ordinance that is as strict as Washington County Ordinance #179, or adopt the Washington County
Ordinance #179 by reference. After September 23, 2010, if aseptic system ordinance adopted in
CITY /TOWNSHIP NAME, has not been revised and/or adopted, the County's ordinance shall
prevail.
As of this date, the Department has not been contacted regarding the status of the City's SSTS
ordinance. The Department is committed to assisting communities with this ordinance revision. If
your community would like assistance from the Department in any way, please contact Chris LeClair
at 651- 430 -6673 or Pete Ganzel at 651- 430 -6676. Once the City's ordinance has been revised or
adopted, please advise the Department as to the effective date of that revision.
Government Center • 14949 62nd Street North — P.O. Box 6, Stillwater, Minnesota 55082 -0006
Phone: 651- 430 -6655 • Fax 651 - 430 -6730 • TTY: 651- 430 -6246
Service Centers also located in Cottage Grove and Forest Lake
www co.
.washington.mn.us
The County Ordinance is posted on the Department's website at
http: / /www.co.washin�lYon.mn.us /info for residents /environment/sc7tic/ordinance revision/ Ifthe
community is interested in receiving a bound,version of Washington County Ordinance 4179, please
contact Stephanie Holt at 651 - 430 -6678 and one will be mailed once they are published.
If you would have any questions or comments about the SSTS Ordinance, please contact Chris
LeClair at 651 -430 -6673, Pete Ganzel at 651- 430 -6676, or me at 651 -430 -6744.
Sincerely,
vta.-�].a_�
Amanda Strommer, Program Manager
Washington County Department of Public Health & Environment
CC: Chris LeClair, Sr. Environmental Specialist
Pete Ganzel, Sr. Environmental Specialist
WASHINGTON COUNTY
DEVELOPMENT CODE
Pursuant to MSA Ch 394, Washington County has adopted official controls for the purposes of regulating the
physical development
of land in the unincorporated areas of the County. These official controls are compiled into
and hereafter
known as the Washington
County Development Code and consists of the following chapters each
adopted by Ordinance.
(1)
Chapter One
Administration
(2)
Chapter Two
Zoning Regulations
(3)
Chapter Three
Subdivision Regulations
(4)
Chapter Four
Subsurface Sewage Treatment System Regulations
(5)
Chapter Five
Lower St. Croix River Bluffland and Shoreland Management Regulations
(6)
Chapter Six
Shoreland Management Regulations
(7)
Chapter Seven
Mining Regulations
(8)
Chapter Eight
201 Sewer Use Regulations
(9)
Chapter Nine
Flood Plain Regulations
(10)
Chapter Ten
Official Map Regulation and Designation
Summary
Washington County Development Code
Chapter Four Subsurface Sewage Treatment System Regulations
Ordinance No. 179
Individual sewage treatment systems, more commonly referred to as septic systems, have been
regulated in Washington County since 1972. There have been numerous iterations of the
ordinance regulating septic systems. In 1997 the Washington County Board of Commissioners
adopted Ordinance No. 128, Individual Sewage Treatment System Regulations. Ordinance No.
128 is the County's current ordinance that regulates the location, design, installation, use and
maintenance of individual sewage treatment systems. The regulations are Chapter Four of the
Washington County Development Code and applies in all areas of Washington County, other
than cities and towns that have adopted ordinances that complied with Minn. Stat. § 115.55 and
the rules promulgated thereunder which were as strict as Ordinance No. 128.
On February 4, 2008, the Minnesota Pollution Control Agency published Minnesota Rules
Chapter 7080 through 7083 governing Subsurface Sewage Treatment Systems (SSTS).
Washington County is required to revise and implement an SSTS Ordinance which complies
with the updated Minnesota Rules Chapters 7080, 7081, 7082, and 7083 by no later than
February 4, 2010. On September 8, 2009, at its public hearing, the Washington County Board of
Commissioners passed a resolution adopting Ordinance No. 179 which will repeal Ordinance
No. 128. A brief summary of Chapter Four Subsurface Sewage Treatment Systems: Ordinance
No. 179 is as follows:
Sections 1, 2, and 3 address the Purpose and Intent of the SSTS ordinance, provides expanded
Definitions and describes how the Ordinance will be Administered. Section 4 establishes the
Compliance Criteria for existing systems, new construction, and those systems receiving
replacement components. Section 5 deals with Acceptable and Prohibited Discharges of those
systems receiving sewage and those systems that receive both sewage and non sewage discharge.
Section 6 addresses Permits, the permitting process, and when permits are required for SSTS.
Permit applications will now require management plans for the proposed system before a permit
can be issued. Section 7 addresses Operating Permits and what must be included in the operating
permits. Operating permits will be required for Type III systems, Type IV systems, Type V
systems, all Midsized Sewage Treatment Systems, Holding tanks, SSTS serving Food Beverage
and Lodging Establishments, and SSTS serving Hazardous Waste Generators. Operating permits
include maintenance requirements, operational requirements, compliance limits and boundaries,
reporting frequency, notification by permitted, identified reserve areas, and prohibited
discharges.
Section 8 addresses when Inspections are required to determine compliance with Chapter Four.
Com nlianee sgections__mus-t b�c�nducted._gnor_to ssu n_ce_of a p mit f4rShe addilaort ofa
bedroom, all new construction and replacement, and prior to the transfer of any real property
unless the age of the property's system is less than 5 years old. Compliance inspections are also
required when deemed necessary by the Department. Section 8 further discusses Certificates of
Compliance and Certificates of Non - Compliance, as well as a process to resolve disputes over
the depth of periodically saturated soil.
Section 9 addresses Site Evaluation and Soil Testing requirements for individual sewage
treatment systems and Section 10 addresses additional Site Evaluation and Soil Testing
requirements for midsized sewage treatment systems. Section 11 addresses Groundwater
Investigation and Section 12 addresses Sewage Flow Determination. Section 13 deals with
Sewage Tanks and the minimum number of required tanks. Section 14 addresses the
Distribution of Effluent, non pressurized distribution pipes, gravity distribution, valve boxes,
distribution boxes, and pressure distribution. Section 15 addresses the Dosing of Effluent and
section 16 addresses Treatment and Dispersal with setback distances and soil hydraulic loading
rates.
Section 17 addresses design standards for Type I Systems, which include trenches, pressure beds,
mounds, and at grades. Section 18 adch-esses Type II Systems, which include systems in rapidly
permeable soils, floodplain systems, holding tanks and privies. Section 19 addresses Type III
Systems, which includes Graywater Systems. Section 20 addresses Type IV Systems, which are
systems that employ registered product. Section 21 addresses Type V Systems, which are
engineered systems.
Section 22 addresses Maintenance in accordance of the SSTS's operating management plan.
Section 23 addresses System Abandonment and Section 24 addresses Product Registration in
accordance of Minn. Rule 7083.4000 to 7083.4120. Section 25 addresses Enforcement of the
Ordinance and Section 26 is for of the Ordinance's Separability. Section 27 addresses the
Effective Date and publication of the Ordinance.
The forgoing is intended only as a summary of the Washington County Development Code
Chapter Four - Subsurface Sewage Treatment System Regulations (SSTS) Ordinance No. 179.
A printed copy of this Ordinance as well as a list of differences between this Ordinance,
Ordinance No 128 and the Minnesota Rules Chapter 7080 is available at the Washington County
Department of Public Health and Environment, the Washington County Auditor- Treasurer's
office, and at the following website:
ht!p://www.co.washington.mn.us/client files/ documents /ohe/ENV/ENV- DraftSSTSRees pdf
Effective September 23, 2009 Chapter Four d- Subsurface Sewage Treatment System Regulations
WASHINGTON COUNTY DEVELOPMENT CODE
CHAPTER FOUR
SUBSURFACE SEWAGE TREATMENT SYSTEM REGULATIONS
Table of Contents
SECTION 1. PURPOSE AND INTENT ................................................................................... ...............................
3
SECTION2. DEFINITIONS ...................................................................................................... ..............................4
SECTION 3 ADMINISTRATION .......................................................................................... ...............................
15
SECTION 4 COMPLIANCE CRITERIA .............................................................................. ...............................
17
SECTION 5 ACCEPTABLE AND PROHIBITED DISCHARGES ...................................... .............................20
SECTION 6 PERMITS... ... ...................... .................. ........... ................... .................................................
-- ..... 21
SECTION 7 OPERATING PERMITS ..................................................................................... .............................23
SECTION 8 INSPECTIONS ...................................................................................................... .............................24
SECTION 9 SITE EVALUATION AND SOIL TESTING..... .... - .... ... - ....... ............... - ....... ............................
28
SECTION 10 MSTS SITE EVALUATION AND SOIL TESTING ....................................... .............................34
SECTION 11 GROUNDWATER INVESTIGATI ON ............................................................. .............................38
SECTION 12 SEWAGE FLOW DETERMINATION ............................................................ .............................40
SECTION13 SEWAGE TANKS .............................................................................................. .............................44
SECTION 14 DISTRIBUTION OF EFFLUENT .................................. ....... ...................... ...........
....................... 50
SECTION 15 DOSING OF EFFLUENT ................................................................................ ...............................
55
SECTION 16 TREATMENT AND DISPERSAL .................................................................... .............................57
SECTION 17 TYPE I SYSTEMS ........................ .. ............................................ ..... ... ................... ........
.................. 63
SECTION 18 TYPE II SYSTEMS .......................................................................................... ...............................
71
SECTION19 TYPE III SYSTEMS ......................................................................................... ...............................
75
SECTION 20 TYPE IV SYSTEMS... ........................... -- ............. ...........................................................
.... — ..... 77
SECTION 21 TYPE V SYSTEMS ............................................................................_............ ...............................
79
SECTION 22 MAINTENANCE... .............................................................................................................
...... 80
SECTION 23 SYSTEM ABANDONMENT ........................................................................... ...............................
83
SECTION 24 PRODUCT REGISTRATION... ....... --- ...... — ....... ... -- ...... ..................... ...............................
84
SECTION25 ENFORCEMENT ..................... ......................... ............ ................... .......... ........ ---
...................... 85
SECTION 26 SEPARABILITY ........ .. ........ .... .... ...... .............. ....... .................. ...... --- ............ .. .............................
85
SECTION27 EFFECTIVE DATE .......................................................................................... ...............................
85
APPENDIX A SOIL LOADING RATES FOR LEVEL C TREATMENT ........................... .............................86
APPENDIX B SOIL LOADING RATES FOR LEVEL A & B TREATMENT ................... .............................89
2 Washington County Development Code
Effective September 23, 2009 Chapter Four -., Subsurface Sewage Treatment System Regulations
WASHINGTON COUNTY DEVELOPMENT CODE
CHAPTER FOUR
SUBSURFACE SEWAGE TREATMENT SYSTEM REGULATIONS
This chapter shall regulate the location, design, installation, use and maintenance of subsurface sewage treatment
systems in all areas of Washington County other than cities and towns that have adopted ordinances that comply
with Minnesota Statute '11.5 55 and are as strict as this Chapter. This chapter is authorized under Minnesota Statute
Section 115.55 and I15.56 and Minnesota Statutes Chapter 145A.
SECTION 1. PURPOSE AND INTENT
1.1 This Chapter is adopted for the following purposes:
(I) To protect the public health, safety, and general welfare by the discharge of adequately treated
sewage to the groundwater via the proper location, design, installation, use, and maintenance of
individual subsurface sewage treatment systems (ISTS) and midsized subsurface sewage treatment
systems (MSTS).
(2) These environmental protection standards shall be adopted county wide and administered and
enforced by the Department or local units of government as directed by Minnesota Rules, Chanter
7082 and Minnesota Statute, Section 115.55.
(3) This chapter does not regulate systems that do not receive sewage as defined in this chapter. If
systems receive both sewage and nonsewage, the requirements of this chapter apply, plus any
additional requirements governing the nonsewage portion of the wastewater.
(4) To provide prescriptive design, construction, and operational standards to reasonably protect
surface water and groundwater and promote public health, safety, and general welfare.
(5) To protect individual water supply wells of the community from contamination by inadequate,
improperly designed, located, installed or maintained subsurface sewage treatment systems.
(6) To provide for the orderly development of areas of the community which are not served by central
public wastewater treatment systems and to reduce the need to install central public wastewater
treatment systems in areas where they are not now currently planned.
(7) Technology and products employed in system design shall adequately protect the public health and
the environment as determined by Minnesota Rules, Chapter 7083, and be approved for use by the
Department or local unit of goverment.
3 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
SECTION 2. DEFINITIONS
2.1 Certain Terms. For the purposes of this Chapter, certain terms or words used are interpreted as follows:
the words "shall" and "must" are mandatory and the words "should" and "may" are permissive. All
distances specified in this Chapter are horizontal distances unless otherwise specified.
2.2 For the purpose of this Chapter, the certain words and phrases are defined as follows:
(1) Absorption area. "Absorption area" means the parameter that is associated with the hydraulic
acceptance of effluent. It is also commonly known as the infiltrative surface. The absorption area
for a mound system is the original soil below a mound system that is designed to absorb sewage
tank effluent. The absorption area for trenches, seepage beds, and at -grade systems is the soil area
in contact with the part of the distribution medium that is designed and loaded to allow absorption
of sewage tarik effluent. This includes both bottom and sidewall soil contact areas.
(2) Agency. "Agency" means the Minnesota Pollution Control Agency (MPCA)_
(3) Alarm device. "Alarm device" means a device that alerts a system operator or system owner of a
component's status using a visual or audible device. An alarm device can be either on site or
remotely located.
(4) Applicable requirements. "Applicable requirements" means:
A. _ This Chapter; Minnesota Rules, Chanter 7082; and, Minnesota Statutes section 115.55; or
B. In areas of the County without complying ordinances to regulate SSTS, the requirements in
this Chapter.
(5) As- builts. "As- builts" means drawings and documentation specifying the final in -place location,
size, and type of all system components. These records identify the results of materials testing and
describe the conditions during construction. An as -built also contains a certified statement.
(6) ASTM. "ASTM' means the American Society for Testing and Materials.
(7) At -grade system. "At -grade system" means a pressurized soil treatment and dispersal system
where sewage tank effluent is dosed to an absorption bed that is constructed directly on original soil
at the ground surface and covered by loamy soil materials.
(8) Baffle. `Baffle" means a device installed in a septic tank to retain solids and includes, but is not
limited to, vented sanitary tees with submerged pipes and effluent screens.
(9) Bedrock. "Bedrock" means geologic layers, of which greater than 50 percent by volume consists
of unweathered in -place consolidated rock or rock fragments. Bedrock also means weathered in-
place rock which cannot be hand angered or penetrated with a knife blade in a soil pit.
(10) Bedroom. `Bedroom" means, for the sole purpose of estimating design flows from dwellings, an
area that is:
A. a room designed or used for sleeping; or
4 Washington County Development Code
Effective September 23, 2009 Chapter Four •3 Subsurface Sewage Treatment System Regulations
B. a room or area of a dwelling that has a minimum floor area of 70 square feet with access
gained from the living area or living area hallway. Architectural features that affect the use
as a bedroom under this item may be considered in making the bedroom determination.
(11) Biochemical oxygen demand or BOD. `Biochemical oxygen demand" or "BOD" means the
measure of the amount of oxygen required by bacteria while stabilizing, digesting, or treating
biodegradable organic matter under aerobic conditions over a five -day incubation period,
commonly expressed in milligrams per liter (mg /L).
(12) Building. `Building" means any structure used or intended for supporting or sheltering any use or
occupancy.
(13) Building sewer. `Building sewer" means the part of the drainage system which extends from the
end of the building drain and conveys its discharge to a subsurface sewage treatment system.
(14) Carbonaceous biochemical oxygen demand or CBOD5- "Carbonaceous biochemical oxygen
demand" or "CBOD5" means the measure of the amount of oxygen required by bacteria while
stabilizing, digesting, or treating organic matter under aerobic conditions over a five -day incubation
period while in the presence of a chemical inhibitor to block nitrification. CBOD5 is commonly
expressed in milligrams per liter (mg/L).
(15) Certificate of compliance. "Certificate of compliance" means a document, written after a
compliance inspection, certifying that a system is in compliance with applicable requirements at the
time of the inspection.
(16) Certified. "Certified" means an individual is included on the Agency's SSTS certification list and
is qualified to design, install, maintain, repair, pump, operate, or inspect an SSTS as appropriate
with the individual's qualifications. A certified individual who is working under a license is subject
to the obligations of the license. Certified individuals were previously known as registered
professionals.
(17) Certified statement. "Certified statement" means a statement signed by a certified individual,
apprentice, or qualified employee under Minnesota Rules, Chapter 7083 certifying that the licensed
business or qualified employee completed the work in accordance with applicable requirements.
(18) Cesspool. "Cesspool' means an underground pit, receptacle, or seepage tank that receives sewage
and leaches sewage into the surrounding soil, bedrock, or other soil materials. Cesspools include
sewage tanks that were designed to be watertight, but subsequently leak below the designed
operating depth.
(19) Clean sand. "Clean sand" means a soil fill material required to be used in mounds. The standards
for clean sand are outlined in Section 17.3 (10).
(20) Commissioner. "Commissioner" means the commissioner of the Minnesota Pollution Control
Agency.
(21) Compliance inspection. "Compliance inspection" means an evaluation, investigation, inspection,
or other such process for the purpose of issuing a certificate of compliance or notice of
noncompliance.
(22) Contour Loading Rate. "Contour Loading Rate" is the amount of effluent loaded to the soil
per length of the dispersal unit or units along the single hillslope along the contour. The
5 Washington County Development Code
Effective September 23, 2009 Chapter Four v Subsurface Sewage Treatment System Regulations
contour loading rate is determined on the relationship between the vertical and horizontal
water movement in soil and is based on the permeability difference between the absorption
area and any deeper horizons, the depth between the absorption area and the change in
permeability; and the land slope.
(23) Department. "Department' means the Washington County Department of Public Health and
Environment.
(24) DNR. "DNR" means the Minnesota Department of Natural Resources.
(25) Disinfection. "Disinfection" means the process of destroying or inactivating pathogenic
microorganisms in sewage to render them noninfectious.
(26) Distinct. "Distinct' means a soil color that is not faint as described in Section 2.2 (39).
(27) Distribution box. "Distribution box" means a device intended to distribute sewage tank effluent
concurrently and equally by gravity to multiple segments of a soil dispersal system.
(28) Distribution device. "Distribution device" means a device used to receive and transfer effluent
from supply pipes to distribution pipes or downslope supply pipes, or both. These devices include,
but are not limited to, drop boxes, valve boxes, distribution boxes, or manifolds.
(29) Distribution medium. "Distribution medium" means the material used to provide void space in a
dispersal component, through which effluent flows and is stored prior to infiltration. Distribution
media includes, but is not limited to, drainfield rock, polystyrene beads, chambers, and gravelless
pipe.
(30) Distribution pipes. "Distribution pipes" means perforated pipes that distribute effluent within a
distribution medium.
(31) Domestic waste. "Domestic waste" means liquid waste produced by toilets, bathing, laundry,
culinary operations, and the floor drains associated with these sources, and includes household
cleaners, medications, and other constituents in sewage restricted to amounts normally used for
domestic purposes. Domestic waste has a biochemical oxygen demand of 175 mg/L or less, a total
suspended solids level of 65 mg /L or less, an oil and grease concentration of 25 mg /L or less and no
hazardous wastes. Animal waste and commercial or industrial waste are not considered domestic
waste.
(32) Drip dispersal system. "Drip dispersal system" means a small diameter pressurized wastewater
distribution system in which the treated effluent is distributed under pressure to the infiltrative
surface via drip tubing and enters the receiving environment.
(33) Drop box. "Drop box" means a distribution device used for the serial gravity application of
sewage tank effluent to a soil dispersal system_
(34) Dwelling. "Dwelling" means any building with provision for living, sanitary, and sleeping
facilities.
(35) Effluent screen. "Effluent screen" means a device installed on the outlet piping of a septic tank for
the purpose of retaining solids of a specific size.
(36) EPA. "EPA" means the United States Environmental Protection Agency.
6 Washington County Development Code
Effective September 23, 2009 Chapter Four •.- Subsurface Sewage Treatment System Regulations
(37) Even Distribution. "Even Distribution" means a method that, upon activation of the SSTS,
reliably distributes effluent over the entire required absorption area.
(38) Existing system. "Existing system" means a system that has been previously inspected and
approved by the Department or local unit of government during installation. In addition, all
operating systems installed before the adoption of this Chapter are considered existing systems.
(39) Faint. "Faint' means a soil color:
A. with the same hue as another soil color but that varies from the other color by two or less
units of value and not more than one unit of chroma;
B. that differs from another soil color by one hue and by one or less units of value and not
more than one unit of chroma; or
C. that differs from another soil color by two units of hue with the same value or chroma.
(40) Fecal coliform or FC. "Fecal cohform" or "FC ", for the purposes of this Chapter, means bacteria
common to the digestive systems of humans that are cultured in standard tests. Counts of these
organisms are typically used to indicate potential contamination from sewage or to describe a level
of disinfection, generally expressed in colonies per 100 naL.
(41) Fine Sand. "Fine sand" means a soil texture, as described in the Field Book for Describing and
Sampling Soils, which is incorporated by reference in Section 2.2 ('46) where more than 50 percent
of the sand has a particle size range of 0.05 millimeters, sieve size of 270, to 0.25 millimeters, sieve
size 60.
(42) Flood fringe. "Flood fringe" means that portion of the floodplain outside of the floodway. Flood
fringe is in the Flood Insurance Study for Washington County and identified on the Flood
Boundary and Floodway Maps as floodway fringe.
(43) Floodplain. "Floodplain" means the area covered by a 100 -year flood event along lakes, rivers,
and streams as published in technical studies by local, state, and federal agencies, or in the absence
of these studies, estimates of the 100 -year flood boundaries and elevations as developed according
to Washington County.
(44) Floodway. "Floodway" means the bed of a wetland or lake, the channel of a watercourse, and
those portions of the adjoining floodplain that are reasonably required to cant' the regional flood
discharge.
(45) Flow measurement. "Flow measurement' means any method to accurately measure water or
sewage flow, including, but not limited to, water meters, event counters, running time clocks, or
electronically controlled dosing.
(46) Geomorphic description. "Geomorphic description" means the identification of the landscape,
landform, and surface morphometry of the proposed area of the soil treatment and dispersal system
as described in the Field Book for Describing and Sampling Soils: Version 2.0 (2002), developed
by the National Soil Survey Center and Natural Resources Conservation Service of the United
States Department of Agriculture. The field book is incorporated by reference, is not subject to
frequent change, and is available through the Minitex interlibrary loan system.
Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
(47) Graywater. " Graywater" means sewage that does not contain toilet wastes. Liquid wastes from a
dwelling or other establishment produced by bathing, laundry, culinary operation, and from floor
drains associated with these sources are considered graywater.
(48) Graywater system. " Graywater system" means a system that receives, treats, and disperses only
graywater or other similar system as designated by the commissioner.
(49) Groundwater mound. "Groundwater mound" means the rise in height of the periodically
saturated soil or regional water table caused by the addition of sewage effluent from a subsurface
sewage treatment system into the soil.
(50) Hazardous waste. "Hazardous waste" means any substance that, when discarded, meets the
definition of hazardous waste in Minnesota Statutes section 116 06 subdivision 11, Minnesota
Rules 7045, or Washington County Ordinance No. 166.
(51) Holding tank. "Holding tank" means a tank for storage of sewage until it can be transported to a
point of treatment and dispersal. Holding tanks are considered a septic system tank under
Minnesota Statutes, section 115.55.
(52) Individual subsurface sewage treatment system or ISTS. "Individual subsurface sewage
treatment system" or "ISTS" means an individual sewage treatment system or part thereof, as set
forth in Minnesota Statutes, sections 115.03 and 115.55, that employs sewage tanks or other
treatment devices with final discharge into the soil below the natural soil elevation or elevated final
grade that are designed to receive a sewage design flow of 5,000 gallons per day or less. ISTS
includes the holding tanks and privies, but does not include any pump tanks used in a sewage
collection system. ISTS does not include building sewers or other components regulated under
Minnesota Rules, Chapter 4715, or sewage collection systems.
(53) Inner wellhead management zone. "Inner wellhead management zone" means the drinking water
supply management area for a public water supply well that does not have a delineated wellhead
protection area approved by the Department of Health under Minnesota Rules, Chapter 4720,
section 4720.5330.
(54) Invert. "Invert' means the lowest point of a channel inside a pipe.
(55) Imminent Threat to Public Health or Safety. "Imminent Threat to Public Health or Safety"
means an ISTS which discharges sewage or sewage effluent to the ground surface, drainage system,
ditches, or storm water drains or directly to surface water; or causes a reoccurring sewage backup
into a dwelling or other establishment; or has an electrical hazard; or includes a sewage tank with
an unsecured, damaged or weak maintenance hole cover; or an ISTS that has received hazardous
waste, or other safety or health hazard as determined by those authorized in Minnesota Rules
Chapter 7083
(56) ISTS Railing to Protect Groundwater. "ISTS Failing to Protect Groundwater" means a seepage
pit, cesspool, drywell, leaching pit or other pit; or an ISTS that has less than the required vertical
separation distance as described in Section 4.3 (4) & tL; or an ISTS not abandoned in accordance
with Section 23; or any other threat to groundwater quality as determined by those authorized in
Minnesota Rules. Chapter 7083.
(57) Liquid capacity. "Liquid capacity" means the liquid volume of a sewage tank below the invert of
the outlet pipe or, for holding tanks and pump tanks, the liquid volume below the invert of the inlet.
8 Washington County Development Code
Effective September 23, 2009 Chapter Four •.- Subsurface Sewage Treatment System Regulations
(58) Long -term sewage treatment. "Long -term sewage treatment" shall mean enough space on a lot
for two Type I or Type II soil treatment and dispersal areas.
(59) Lot. "Lot' means a parcel of land designated by metes and bounds, registered land survey, plat or
other means, and which description is either recorded in the Office of the Washington County
Recorder or Registrar of Titles or used by the County Treasurer or County Assessor to separate
such parcel from other lands for tax purposes.
(60) Management plan. "Management plan" means a plan that requires the periodic examination,
adjustment, testing, and other operational requirements to meet system performance expectations,
including a planned course of action in the event a system does not meet performance expectations.
(61) Matrix. "Matrix" means the majority of the color in a soil horizon, as described in the Field Book
for Describing and Samples Soils, which is incorporated by reference in Section 2.2 (46).
(62) Midsized subsurface sewage treatment system or MSTS. "Midsized subsurface sewage
treatment system" or' :MSTS" means an individual sewage treatment system, or part thereof, as set
forth in Minnesota Statutes sections 115.03 and 115.55, that employs sewage tanks or other treatment
devices with final discharge into the soil below the natural soil elevation or elevated final grade and
that is designed to receive sewage from dwellings or other establishments with a design flow of
greater than 5,000 gallons per day to 10,000 gallons per day. Design flows must be determined by
Section 12.7. MSTS also includes on -lot septic tanks, holding tanks, and privies, but does not include
any pump tanks used in a sewage collection system. MSTS does not include those components
defined as plumbing under Minnesota Rules Chanter 4715 or sewage collection systems.
(63) Mottles. "Mottles" means the minority of the variegated colors in a soil horizon, as described in
the Field Book for Describin" and Sampling Soils, which is incorporated by reference in Section
2.206).
(64) Mound system. "Mound system" means a soil treatment and dispersal system designed and
installed such that all of the infiltrative surface is installed above grade, using clean sand between
the bottom of the infiltrative surface and the original ground elevation, utilizing pressure
distribution and capped with suitable soil material to stabilize the surface and encourage vegetative
growth.
(65) MPCA. "MPCA" means the Minnesota Pollution Control Agency.
(66) NPDES permit. "NPDES permit' means a National Pollutant Discharge Elimination System
permit issued by the MPCA.
(67) New construction "New construction" means installing or constructing a new ISTS or altering,
extending, or adding capacity to an existing system.
(68) Notice of noncompliance. `?Notice of noncompliance" means a document written and signed by a
certified inspector after a compliance inspection that gives notice that an ISTS is not in compliance
with this Chapter.
(69) O &G. "O &G" means oil and grease, a component of sewage typically originating from foodstuffs
such as animal fats or vegetable oils or consisting of compounds of alcohol or glycerol with fatty
acids such as soaps and lotions, typically expressed in mg /L (also known as FOG, or fats, oiI and
grease).
9 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
(70) Ordinary high water level. ""Ordinary high water level" means the boundary of water basins,
watercourses, public waters, and public waters wetlands, and:
k the ordinary high water level is an elevation delineating the highest water level that has
been maintained for a sufficient period of time to leave evidence upon the landscape,
commonly the point where the natural vegetation changes from predominantly aquatic to
predominantly terrestrial;
B. for watercourses, the ordinary high water level is the elevation of the top of the bank of the
channel; and
C. for reservoirs and flowages, the ordinary high water level is the operating elevation of the
normal summer pool.
(71) Original soil. "Original soil" means naturally occurring soil that has not been cut, filled, moved,
smeared, compacted, altered, or manipulated to the degree that the loading rate must be reduced
from that associated with natural soil conditions.
(72) Other establishment. "Other establishment" means any public or private structure other than a
dwelling that generates sewage that discharges into an ISTS or MSTS.
(73) Other pit. "Other pit" means any pit or other device designed to leach sewage effluent that is
greater than 30 inches in height or has a bottom area loading rate of sewage greater than two
gallons per square foot per day.
(74) Owner. "Owner" means any person having possession of, control over, or title to property with an
ISTS.
(75) Parent material. "Parent material" means the unconsolidated and chemically weathered geologic
mineral or organic matter from which soils are developed by soil forming processes.
(76) Percolation rate. "Percolation rate" means the rate of a drop of water infiltrating into a test hole as
specified in Section 9.7 (2).
(77) Periodically saturated soil. "Periodically saturated soil" means the highest elevation in the soil
that is in a reduced chemical state due to soil pores filled or nearly filled with water causing
anaerobic conditions. Periodically saturated soil is determined by the presence of redoximorphic
features in conjunction with other established indicators as specified in Section 9.6 (5) or L6), or
determined by other scientifically established technical methods or empirical field measurements
acceptable to the local unit of government in consultation with the Department or the
commissioner.
(78) Permit. "Permit" means a building, construction, sanitary, planning, zoning or other such permit
issued for new construction, replacement, repair, alteration or extension of a subsurface sewage
treatment system. Permit also means a permit issued for the addition of a bedroom or bathroom on
property served by a subsurface sewage treatment system.
(79) Permittee. " Permittee" means a person who is named on a permit issued pursuant to these
regulations.
(80) Plastic limit. "Plastic limit" means a soil moisture content above which manipulation will cause
compaction or smearing. The plastic limit can be measured by American Society for Testing and
10 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
Materials, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils,
ASTM D4318 (2005). The standard is incorporated by reference, is available through the Minitex
interlibrary loan system, and is not subject to frequent change.
(81) Pressure distribution. "Pressure distribution" means a network of distribution pipes in which
effluent is forced through orifices under pressure.
(82) Privy. "Privy" means an aboveground structure with an underground cavity meeting the
requirements of Section 18.4 that is used for the storage or treatment and dispersal of toilet wastes,
excluding water for flushing and graywater. A privy also means a nondwelling stricture containing
a toilet waste treatment device.
(83) Proprietary product. "Proprietary product" means a sewage treatment or distribution technology,
method, or material subject to a patent or trademark.
(84) Public domain technology. "Public domain technology" means a sewage treatment or distribution
technology, method, or material not subject to a patent or trademark.
(85) Public waters. 'Public waters" means any public waters or wetlands defined in Minnesota
Statutes section 103G.005, subdivision 15, or identified as public waters or wetlands by the
inventory prepared according to Minnesota Statutes section 103G.20 1.
(86) Pump tank. "Pump tank" means a tank or separate compartment following the sewage tank that
serves as a reservoir for a pump. A separate tank used as a pump tank is considered a septic system
tank under Minnesota Statutes section 115.55. subdivision 1 paragra h (o).
(87) Redoximorphic features. "Redoximorphic features" means:
A. a color pattern in soil, formed by oxidation and reduction of iron and manganese in
saturated soil coupled with their removal, translocation, or accrual, which results in the loss
(depletion) or gain (concentration) of mineral compounds compared to the matrix color; or
B. a soil matrix color controlled by the presence of ferrous iron. Redoximorphic features are
described in Section 9.6 (5l.
(88) Replacement. "Replacement" means the removal or discontinued use of any major portion of an
ISTS and reinstallation of that portion of the system, such as reinstallation of a new sewage tank,
holding tank, pump tank, privy, or soil dispersal system.
(89) SDS permit. "SDS permit' means a State Disposal System permit issued by the MPCA.
(90) Sand. "Sand" means a sand soil texture, as described in the Field Book for Describm and
Sampling Soils, which is incorporated by reference in Section 2.2 46 .
(91) Seepage bed. "Seepage bed" means a soil treatment and dispersal system, the absorption width of
which is greater than three feet but no greater than 25 feet.
(92) Seepage pit. "Seepage pit" means an underground pit that receives sewage tank effluent and from
which the liquid seeps into the surrounding soil.
(93) Septage. "Septage" means solids and liquids removed from an SSTS and includes solids and
liquids from cesspools, seepage pits, other pits, or similar systems or devices that receive sewage.
11 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
Septage also includes solids and liquids that are removed from portable, incinerating, composting,
holding, or other toilets. Waste from Type III marine sanitation devices, as defined in Code of
Federal Regulations, title 33 section 1593, and material that has come into contact with untreated
sewage within the past 12 months is also considered septage.
(94) Septic tank. "Septic tank" means any watertight, covered receptacle that is designed and
constructed to receive the discharge of sewage from a building sewer or preceding tank, stores
liquids for a detention period that provides separation of solids from liquid and digestion of organic
matter, and allows the effluent to discharge to a succeeding tank, treatment device, or soil dispersal
area.
(95) Serial distribution. "Serial distribution" means distribution of sewage tank effluent by gravity
flow that progressively loads one section of a soil treatment and dispersal system to a
predetermined level before overflowing to the succeeding section and does not place a dynamic
head on the lower section of the soil treatment and dispersal system. The distribution medium is
allowed to serve as a conveyance medium to the next section.
(96) Setback. "Setback" means a separation distance measured horizontally.
(97) Sewage. "Sewage" means waste produced by toilets, bathing, laundry, culinary operations, and the
floor drains associated with these sources, and includes household cleaners, medications, and other
constituents in sewage restricted to amounts normally used for domestic purposes.
(98) Sewage flow. "Sewage flow" means flow as determined by measurement of actual water
measurement; or, if actual measurements are not available, by the best available data provided.
(99) Sewage tank. "Sewage tank" means a receptacle used in the containment or treatment of sewage
and includes, but is not limited to, septic tanks, aerobic tanks, pump tanks, and holding tanks.
Requirements for sewage tanks are described in Section 13 of this Chapter. Sewage tanks are
considered a septic system in Minnesota Statutes, section 115.55, subdivision 1, Paragraph (o).
(100) Sewage tank effluent. "Sewage tank effluent" means the liquid that flows from a septic tank or
other treatment device.
(191) Site. "Site" means the area required for the proper location of the soil treatment system.
(102) Slope. "Slope" means the vertical rise or fall divided by the horizontal distance, expressed as a
percentage.
(103) Soil dispersal area. "Soil dispersal area" means the area required for the soil dispersal system,
including space between individual units or zones.
(104) Soil dispersal system. "Soil dispersal system" means a system where sewage effluent is dispersed
into the soil for treatment by absorption and filtration and includes, but is not limited to, trenches,
seepage beds, at -grade systems, mound systems and drip dispersal systems.
(105) Soil texture. "Soil texture" means the soil particle size classification and particle size distribution
as specified in the Field Book for Describing and Sampling Soils, incorporated by reference in
Section 2.2 (46).
(106) Subsoil. "Subsoil" means a soil layer that has a moist color value of 3.5 or greater and has
undergone weathering and soil formation processes.
12 Washington County Development Code
Effective September 23, 2009 Chapter Four d• Subsurface Sewage Treatment System Regulations
(107) Subsurface sewage treatment system or SSTS. "Subsurface sewage treatment system" or
"SSTS" is either an individual subsurface sewage treatment system as defined in Section 2.2 (52) or
a midsized subsurface sewage treatment system as defined in Section 2.2 (62), as applicable.
(108) Supply pipe. "Supply pipe" means a nonperforated pipe, the purpose of which is to transport
sewage tank effluent.
(109) Systems in shoreland areas or wellhead protection areas or systems serving food, beverage, or
lodging establishments, or SWF. "Systems in shoreland areas or wellhead protection areas or
systems serving food, beverage, or lodging establishments ", or "SWF ", means the following three
categories:
A. SSTS constructed in shoreland areas where land adjacent to public waters has been
designated and delineated as shoreland in Chanter Six of the Washington County
Development Code;
B. SSTS constructed in wellhead protection areas regulated under Minnesota Statute, chapter
103I; and
C. SSTS serving food, beverage, and lodging establishments that are required to obtain a
licenses under Minnesota Statutes section 157 16 subdivision 1, and Washington County
Ordinance No. 145 or 146, and includes manufactured home parks and recreational
camping areas licensed according to Minnesota Statutes, chapter 327 and Washington
County Ordinance No 147.
(110) TN. "TN" means total nitrogen, which is the measure of the complete nitrogen content in
wastewater, including nitrate (NO3), nitrite (N021 ammonia (NliA and organic nitrogen,
expressed as mg/L.
(111) TP. "TP" means total phosphorus, which is the sum of all forms of phosphorus in effluent,
expressed in mg /L.
(112) Ten -year flood. "Ten -year flood" means the flood which can be expected to occur, on an average,
of once in ten years, or the elevation to which flood waters have a ten percent chance of rising in
any given year.
(113) Toilet waste. "Toilet waste" means waste commonly disposed of in toilets, including fecal matter,
urine, toilet paper, and water used for flushing.
(114) Toilet waste treatment devices. "Toilet waste treatment devices" means other toilet waste
apparatuses including incinerating, composting, biological, chemical, recirculating, or holding
toilets or portable restrooms.
(115) Topsoil. "Topsoil' means the natural, in -place organically enriched soil layer with a color value of
less than 3.5.
(116) Topsoil borrow. "Topsoil borrow" means a loamy soil material having:
A. less than five percent material larger than two millimeters, No. 10 sieve;
B. no material larger than 2.5 centimeters;
Effective September 23, 2009 Chapter Four •:• Subsurface Sewage Treatment System Regutations
C. a moist color value of less than 3.5; and,
D. adequate nutrients and pH to sustain healthy plant growth.
(117) Total suspended solids or TSS. "Total suspended solids" or "TSS" means solids that are in
suspension in water and that are removable by laboratory filtering, expressed as mg /L.
(118) Trench. "Trench" means a soil treatment and dispersal system, the absorption width of which is 36
inches or less.
(119) Valve box. "Valve box" means awatertight structure designed for alternate distribution of sewage
tank effluent to segments of a soil treatment system.
(120) Vertical separation. "Vertical separation" means the vertical measurement of unsaturated soil or
sand between the bottom of the distribution medium and the periodically saturated soil level or
bedrock.
(121) Watertight. "Watertight" means constructed so that no liquid can get into or out of a device except
through designed inlets and outlets.
(122) Well capture zone. "Well capture zone" means the surface and subsurface area that supplies water
to a water supply well.
(123) Wellhead protection area. "Wellhead protection area" means the surface and subsurface area
surrounding a well or well field that supplies a public water system, through which contaminants
are likely to move toward and reach the well field as regulated under Minnesota Rules, Chapter
4720. For the purposes of this chapter, wellhead protection area is that area bounded by the
drinking water supply management area as regulated under Minnesota Rules, Chapter 4720.
14 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
SECTION 3 ADMINISTRATION
3.1 This chapter shall apply and be in effect in all areas in Washington County other than cities and towns that
have adopted ordinances that comply with Minnesota Statute Section 115.55 ' Minnesota Rules. Chanter
7082 and are as strict as this Chapter. Pursuant to Chanter One, the Washington County Department of
Public Health and Environment shall be the Administrator of these regulations.
3.2 SSTS must be designed, constructed and operated according to this Chapter, except as modified through a
local ordinance in compliance with Minnesota Rules Chapter 7082, Minnesota Statutes section 115 55,
and this Chapter.
3.3 SSTS, including both ISTS and MSTS, must be designed, installed, inspected, pumped, serviced, and
operated by licensed businesses and certified individuals meeting the qualifications in Minnesota Rules
7083.0700 to 7083.2040 and any other applicable state or local requirements.
3.4 SSTS that are designed to receive sewage or nonsewage from a two family dwelling or greater or receive
sewage or nonsewage from another establishment that serves more than 20 persons per day, are regulated
by the United States Environmental Protection Agency as Class V injection wells under Code of Federal
Regulations t the 40 Harts 144 and 1.46. Code of Federal Regulations title 40 Harts 144 and 186 prescribe
additional design regulations applicable to certain systems designed under this Chapter. In addition, single
family dwellings that receive nonsewage wastewater are regulated by these federal regulations. All systems
that receive hazardous wastes are regulated by the Unites States Environmental Protection Agency as Class
IV injection wells. Disposal of hazardous waste must be according to state and federal regulations. The
owner or owner's agent of a new or replacement system classified as a Class V injection wells shall submit
to the commissioner of the MPCA and the United States Environmental Protection Agency the inventory
information specified in Code of Federal Reeulations t the 40 section 144 26. All Class V injection wells
must be identified as such in property transfer disclosures.
3.5 If the Department finds that by reason of exceptional circumstances, the strict enforcement of any
provisions of this Chapter would cause undue hardship or that strict conformity with the standards would be
unreasonable, impractical, or not feasible under the circumstances, the Department may permit
modifications in individual cases based on conditions it may prescribe for prevention, control or abatement
of pollution. The Department or local unit of government cannot issue variances for Sections 4. 1, 4.7 4.9
4. 10, and Sections 16.2 (1) through Sect on 16.2 (4l. The Department or local unit of government can grant
a variance for Section 4.9 (4) (A) for replacement MSTS serving existing dwellings or other
establishments..
3.6 Consistent with the procedures in Chanter One. Section 6.1 (1), the Washington County Board of
Adjustment and Appeals shall hear and decide appeals of any order, decision or determination made by the
department regarding the enforcement of this Chapter. Appeals of any administrative decision or
determination may be filed by any person, county department, or township.
3.7 Consistent with the procedures in Chanter One, Section 6 1 (2), the Washington County Board of
Adjustment and Appeals shall hear and decide all requests for variance to the requirements of this Chapter.
3.8 All subsurface sewage treatment systems installed subsequent to the adoption of this Chapter and all
alterations, extensions, modifications or repairs to existing systems irrespective of the date of original
installation shall be regulated in accordance with all requirements of this Chapter.
3.9 All MSTS must be designed and operated according to this Chapter. All MSTS must be designed, installed,
inspected, pumped and operated by licensed businesses meeting the qualifications of Minnesota Rules
Chanter 7083. All MSTS must conform to applicable state statutes and rules. All septage generated from
Effective September 23, 2009 Chapter Four B• Subsurface Sewage Treatment System Regulations
MSTS must be treated and dispersed to applicable standards for septage in Code of Federal Regulations
title 40, part 503, and any local requirements.
3.10 Any new or existing system which discharges to surface waters or the ground surface must obtain either an
NPDES or an SDS permit from the MPCA and shall comply with all NPDES or SDS requirements.
3.11 MSTS must conform to all applicable state statutes and rules. MSTS serving establishments licensed or
regulated by the State of Minnesota, or MSTS owned by the State of Minnesota, must conform to this
Chapter.
3.12 Any SSTS requiring approval from the State of Minnesota shall also comply with all requirements of this
Chapter, and all local codes and ordinances.
3.13 Where work requiring a permit under this Chapter has commenced without first having obtained such
permit, work shall be ordered to stop by the Department until all required permits have been approved and
issued.
3.14 To enforce this Chapter, the Department or its authorized agent may enter a building, property, or a place
where there is reason to suspect that a system is failing to protect groundwater or an imminent threat to
public health and safety.
3.15 Fees for permits, operating permits, inspections, or other services rendered under this Chapter shall be
established by the Washington County Board of Commissioners.
16 Washington County Development Code
Effective September 23, 2009 Chapter Four 4 Subsurface Sewage Treatment System Regulations
SECTION 4 COMPLIANCE CRITERIA
4.1 Treatment required. Sewage discharged from a dwelling or other establishment that is not served by a
system issued a permit containing effluent and discharge limits or specific monitoring requirements by the
Department or Agency must be treated according to applicable requirements.
4.2 Compliance criteria for new construction. An SSTS regulated under a current permit is considered
compliant if it meets the applicable requirements of Section 16 to Section 21.
4.3 Compliance criteria for existing systems. To be in compliance, an existing SSTS must meet the
provisions of this subpart.
(1) The SSTS must be protective of public health and safety. A system that is not protective is
considered an imminent threat to public health or safety. At a minimum, a system that is an
imminent threat to public health or safety is a cesspool, seepage pit, drywell or leaching pit, a
system with discharge of sewage or sewage effluent to the ground surface, drainage systems,
ditches, or storm water drains or directly to surface water; systems that cause a reoccurring sewage
backup into a dwelling or other establishment; systems with electrical hazards; or sewage tanks
with unsecured, damaged, or weak maintenance hole covers. A determination of protectiveness for
other conditions must be made by a qualified employee of the Department or licensed inspection
business.
(2) The SSTS must be protective of groundwater. A system that is not protective is considered a
system failing to protect groundwater. At a minimum, a system that is failing to protect
groundwater is a system that is a seepage pit, cesspool, drywell, leaching pit, or other pit; a system
with less than the required vertical separation distance described in Section 4.3 ('4) and Section 4.3
of this Section; and a system not abandoned in accordance with Section 23. A determination of
the threat to groundwater quality for other conditions must be made by a qualified employee of the
Department or local unit of government or licensed inspection business.
(3) The SSTS must be operated, meet performance standards, and be managed according to its
operating permit.
(4) SSTS built after March 31, 1996, or in an SWF area as defined in Section 2.2 f 109), shall have a
three (3) foot vertical separation. No more than a fifteen (15) percent reduction in the vertical
separation distance is allowed to account for settling of sand or soil, normal variation of
measurements, and interpretations of the limiting layer conditions.
(5) SSTS built before April 1, 1996, in areas that are not SWF areas as defined in Section 2.2 (109),
must have at least two (2) feet of vertical separation.
(6) The vertical separation measurement for Section 4.3 (4) and Sect on 4.3 (5) shall be measured
outside of the area of system influence in an area of similar soil and on the same contour elevation.
(7) An existing system which is found to be an imminent threat to public health and safety by either a
qualified employees of the Department, local unit of government, or a licensed inspection business,
is hereby declared to be a public health nuisance and shall be repaired, upgraded, replaced or its use
discontinued within thirty (30) days of notice and order to comply by the Department. Any further
discharge of effluent must be stopped immediately (by such methods as reducing or stopping all
water use or pumping the tank as necessary) until such time as the system is corrected.
17 Washington County Development Code
Effective September 23, 2009 Chapter Four B• Subsurface Sewage Treatment System Regulations
(8) Any existing system which is found to be failing to protect groundwater shall be replaced or
otherwise brought into compliance within ninety (90) days of notice and order to comply by the
Department.
(9) An existing system that is not otherwise considered an imminent threat to public health and safety
and which was constructed under a permit issued by the Department, or other local unit of
government that verified that the required vertical separation existed at the time of installation, need
not be upgraded, repaired, replaced, or its use discontinued notwithstanding the fact that at the time
of a compliance inspection, there appears to be less than the required vertical separation between
the system bottom and any limiting layer.
4.4 Compliance criteria for systems with a flow of greater than 2,500 gallons per day. In addition to the
requirements under Section 4.3, systems designed under Section 16.4 must demonstrate that the additional
nutrient reduction component required under those items is in place and functioning.
4.5 Compliance criteria for systems receiving replacement components. Components of an existing system
that result in the system being in noncompliance must be repaired or replaced according to this Chapter.
The repaired or replacement components must meet technical standards and criteria of this Chapter. The
remaining components of the existing system must result in the system being in compliance with Section
4_3. If a compliant existing sewage tank is to be used with the design of the new soil dispersal system, the
tank must also be baffled and be watertight.
4.6 New construction, replacement, or existing MSTS designed under this Chapter are considered conforming
if they meet the requirements of this Chapter. Existing MSTS constructed before the effective date of this
Chapter are considered conforming if they meet the requirements of this Section, except for Section 4.9 (4)
and Section 4.9 (5).
4.7 To be in compliance, all MSTS must:
(1) have treatment processes and devices that do not allow sewage or sewage effluent contact with
humans, insects, or vermin;
(2) disperse sewage effluent into our soil or sand below final grade, with the effluent remaining below
final grade;
(3) not discharge to drainage tile, the ground surface, or surface water or back up sewage into
dwellings or other establishments;
(4) treat and disperse sewage effluent in a safe manner, including protection from physical injury and
harm; and
(5) not have received hazardous material.
4.8 MSTS must be considered an imminent threat to public health and safety for noncompliance with Section
4.7 and any other condition that poses an imminent threat as determined by a qualified employee of the
Department or licensed MSTS inspection business.
4.9 To be in compliance, all MSTS must:
(1) maintain a zone of unsaturated soil between the bottom of the soil treatment and dispersal system
and the periodically saturated soil or bedrock during loading of effluent, as described in Section
16.5(9).
18 Washington County Development Code
Effective September 23, 2009 Chapter Four 4 Subsurface Sewage Treatment System Regulations
(2) not be seepage pits, cesspools, drywells, leaching pits, sewage tanks, and treatment vessels that
observably leak below the designated operating depth;
(3) not allow viable fecal organisms to contaminate underground waters or zones of seasonal
saturation;
(4) employ nitrogen reduction processes that reduce nitrogen contribution to groundwater as
determined:
(A) if the discharge from an MSTS will impact water quality of an aquifer, as defined in
?Minnesota Rules Chanter 4725.0100 sub ap t 21, the effluent from an MSTS, in
combination with the effective recharge to the groundwater, must not exceed a
concentration of total nitrogen of 10 mg /L or greater at the property boundary or nearest
receptor, which is closest; or
(B) if the discharge from an MSTS will not impact water quality of an aquifer, as defined in
Minnesota Rules Chapter 4725 0100 subpart 21, best management practices developed by
the Commissioner to mitigate water quality impacts to groundwater must be employed; and
(5) not exceed a groundwater discharge of phosphorus to a surface water that exceeds the phosphorus
standard to the receiving water.
4.10 To be in compliance, all MSTS must meet the following requirements:
(1) All methods and devices used to treat and disperse sewage must be designed to conform to all
applicable federal, state and local regulations.
(2) Systems no longer in use must be abandoned according to Section 23.
4.11 To be in compliance, MSTS must meet performance standards and be operated and managed according to
its operating permit and management plan, as described in Section 22.1. To be in compliance, an MSTS
designed before the effective date of this Chapter must be operated according to applicable requirements in
Section 22,
4.12 Components of existing MSTS that cause non - compliance must be repaired or replaced. The repaired or
replaced components must meet technical standards and criteria of this Chapter. The remaining
components must comply with Section 4.1 to Section 4.10, including Section 4.9 (4 , if constructed after the
effective date of this Chapter.
4.13 MSTS in compliance with this Chapter shall be issued a certificate of compliance. MSTS found not in
compliance with this Chapter shall be issued a notice of noncompliance.
4.14 MSTS issued a notice of noncompliance based on the criteria in Sections 4.7 and 4_8 shall be repaired ore
replaced within 30 days or as directed by Minnesota Statutes Chapter 145A whichever is more restrictive.
4.15 MSTS issued a notice of noncompliance based on criteria in Section 4.9 or Section 4.10 shall be repaired or
replaced according to this chapter.
4.16 Systems issued a notice of non - compliance based on criteria in Section 4.11 must immediately be
maintained, monitored, or managed according to the operating permit.
19 Washington County Development Code
Effective September 23, 2009 Chapter Four L• Subsurface Sewage Treatment System Regulations
SECTION 5 ACCEPTABLE AND PROHIBITED DISCHARGES
5.1 This Chapter provides design standards for SSTS that receive sewage. If an SSTS receives both sewage
and nonsewage, the requirements of this chapter and requirements governing the nonsewage portion of the
water apply.
5.2 Footing or roof drainage and chemically treated hot tub and pool water must not be discharged into any
part of the system.
5.3 Products containing hazardous waste must not be discharged to a system, other than in normal amounts of
household products and cleaners designed for household use. Substances not intended for use in
household cleaning, including but not limited to, solvents, pesticides, flammables, photo finishing
chemicals, paint, and dry- cleaning chemicals must not be discharged to the system. Other unused
products or substances, or unused medicines, must not be discharged to the system solely as a disposal
method.
5.4 Floor drains from garages serving dwellings, vehicle maintenance businesses, or any other floor drain that
has the potential to introduce hazardous waste into the system, must not be connected to the system.
5.5 Only domestic waste shall be discharged to a soil dispersal and treatment area. Sewage tank effluent with
a waste strength higher than domestic waste shall be pre - treated to a level equal to or less than domestic
waste prior to final treatment and disposal in a soil treatment and dispersal area.
20 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
SECTION 6 PERMITS
6.1 No construction shall be allowed by any local unit of government until the permit required for the
subsurface sewage treatment system has been issued.
6.2 No additions, enlargements, improvements, or remodeling involving fifty (50) percent or more of the
structure, or alterations that would affect the water use, such as bedrooms, bathrooms or additions to living
space (excluding such areas as screen porches, entry ways, decks, attics, patios, nonhabitable storage space)
shall be allowed until the subsurface sewage treatment system has been determined to be both adequate and
conforming or a permit for a new treatment system has first been issued.
6.3 Permits shall be required for subsurface sewage treatment systems as follows:
(1) All new installations of sewage tanks, soil dispersal and treatment areas, and components thereof;
(2) All repair, extension, replacement or modification of existing systems and components; or
(3) Any change in use of a facility served by a subsurface sewage treatment system.
6.4 Permits shall not be required for normal routine inspection and maintenance of approved individual
subsurface sewage treatment systems that do not require an operating permit.
6.5 Permit applications shall be made in writing on forms provided by the Department and shall contain data,
including, but not limited to, to be considered a completed permit application:
(1) Correct legal description of the property, including Property Identification Number or GEO Code;
(2) Site plan, drawn to scale, showing the location of all proposed and existing structures, property
lines, water supply wells within 100 feet, terrain features, such as blufflines, water bodies or water
ways, buried utilities, easements, and other unique features of the site;
(3) Soil test date, including soil boring logs, percolation test data with field notes (where required) and
location and identification of test area.
(4) Plans and details of the proposed installation of work, including engineering data and final design.
(5) Building plans showing existing and proposed room arrangement and uses.
(6) For other than dwellings, calculated or measured water use rates, occupancy and occupant load.
(7) In certain cases, a property survey may be required identifying property characteristics and
including such items as elevations, contour lines, nonnal high water marks, and ten (10) year and
one hundred (100) year flood elevations.
(8) Evidence of compliance with state or other jurisdiction regulations where applicable.
(9) A management plan for the proposed system, as described in Section 22.1.
6.6 No permit will be issued until a detailed system design is submitted for the current proposed construction,
including site plan, a management plan and at least one current soil boring if there is reason to believe soil
conditions have been altered since the original soil testing.
Effective September 23, 2009 Chapter Four <y, Subsurface Sewage Treatment System Regulations
6.7 Permits shall be valid upon issuance and shall continue for a period of one (1) year. After one (1) year, the
permit may be renewed if no changes are proposed. Such renewal shall require reapplication and payment
of the established fee.
6.8 Permits issued under this Chapter may be revoked upon written notice by the department when such permit
has been issued based on erroneous or inaccurate data supplied by the applicant or erroneous interpretation
of the law by a building official.
22 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
SECTION 7 OPERATING PERMITS
7.1 Operating permits are required for the following systems:
(1) Type III Systems
(2) Type IV Systems
(3) Type V Systems
(4) All MSTS
(5) Holding tanks as described in Section 18.5.
(6) Food, Beverage and Lodging Establishments that discharge high - strength waste to the soil
treatment area.
(7) Hazardous Waste Generators with subsurface sewage treatment systems.
7.2 Operating permits will be issued by the Department or the local unit of government.
7.3 Operating permits must include:
(1) Maintenance requirements, including frequency of maintenance.
(2) Operational requirements.
(3) Compliance Iimits and boundaries.
(4) Reporting frequency.
(5) A requirement that the permittee notify the Department or local unit of government when permit
requirements are not met. Corrective actions must be taken as directed by the Department of local
unit of goverment.
(6) Disclosure of the location and condition of the additional soil treatment and dispersal system; and
(7) A stipulation of acceptable and prohibited discharges.
23 Washington County Development Code
Effective September 23, 2009 Chapter Four d• Subsurface Sewage Treatment System Regulations
SECTION 8 INSPECTIONS
�$a Inspections as required to determine compliance with this Chapter shall be performed by the Department or
its authorized agent under the following circumstances:
(1) Site inspections to verify and evaluate soil and site conditions and to determine the suitability of
soils and system design prior to permit issuance.
(2) Necessary investigation to determine compliance of existing systems at the time of remodeling,
alteration or additions.
(3) For all new SSTS construction or replacement.
(4) Mound systems require a minimum of three construction inspections:
(A) When the original soil under the mound has been roughened, but prior to placement of the
sand fill. Enough of the proposed sand fill must be present to be viewed.
(B) After placement of rock and piping, but prior to cover.
(C) When the mound is completed.
8.2 Installation inspections shall be made by the Department prior to any work having been covered by backfill.
8.3 The licensed installation business shall be responsible to notify the Department a minimum of twenty -four
(24) hours prior to the time work is ready for inspection or reinspection.
8.4 Work which is backfilled prior to a required inspection may be ordered to be uncovered whenever
necessary to determine compliance.
8.5 If upon inspection any part of the system is determined not to be in compliance with this Chapter, written
notice shall be provided by the Department indicating the deficiency and the required corrections. Noted
deficiencies shall be properly corrected and reinspected before any other work on the project is continued.
8.6 No system shall be placed or replaced in service until a final inspection has been completed and the system
installation has been approved.
8.7 The owner or occupant of a property shall be responsible to provide access at a reasonable time to the
Department or its authorized agent for the purpose of performing inspections required under this Chapter.
8,8 The Contractor, upon completion of installation, shall file with the Department as -built drawings indicating
the location of system components dimensioned from a permanent reference point.
8.9 If an inspection is conducted as a part of preparation of the disclosure required by Minnesota Statutes
115.55. subd_ 6 and such inspection is conducted by a party who is not the property owner, such party must
be licensed in accordance with MPCA rules and regulations and the notice of compliance or noncompliance
provided to the property owner roust also be provided to Washington County within thirty (30) days of the
inspection.
8.10 Compliance Inspections must be conducted:
(1) to ensure compliance with applicable requirements;
24 Washington County Development Code
Effective September 23, 2009 Chapter Four d• Subsurface Sewage Treatment System Regulations
(2) prior to the transfer of any real property, unless the age of the system is less than 5 years.
(3) to ensure compliance before issuance of a permit for the addition of a bedroom on property served by
an SSTS;
(4) for all new construction or replacement;
(5) by a qualified employee or licensed inspection business, authorized by the Department or local unit of
government, who is independent of the owner and the installer; and
(6) for an evaluation, investigation, inspection, recommendation, or other process used to prepare a
disclosure if conducted by a party who is not the system owner. The disclosure action constitutes a
compliance inspection and must be conducted according to Minnesota Rules, Chanter 7082;
(7) when deemed necessary by the Department to ascertain the compliance of an existing system.
8.11 A licensed inspection business that inspects an existing SSTS is allowed to subsequently design and install a
new SSTS for that property, provided the inspection business is also licensed to design and install. A licensed
inspection business working on behalf of the Department or local unit of government must not design or
install a system if there is likelihood that the inspector or business will be responsible for permitting or
inspecting the system or system site. A person working for or on behalf of the Department or local unit of
government is not allowed to use the person's position to solicit for private business gain.
8.12 An appropriately licensed SSTS business may inspect an existing system which they installed once it has been
independently inspected.
8.13 Certificate of compliance; notice of noncompliance.
(1) SSTS in compliance with applicable requirements must be issued a certificate of compliance and
systems found not in compliance must be issued a notice of noncompliance. SSTS not in compliance
with Section 4.3 (1) or Section 4.7 must be repaired or replaced within 30 days or as directed under
Minnesota Statutes chanter 145A. Systems out of compliance with other applicable requirements
must be repaired or replaced according to local ordinance requirements. Systems issued a notice of
noncompliance for operational or monitoring deficiencies must immediately be maintained,
monitored, or managed according to the operating permit.
(2) The initial certificate of compliance must be issued if reasonable assurance is evident that the system
was built according to applicable requirements as specified in the construction permit.
(3) The certificate of compliance for new construction and replacement must include the vertical
separation distance report described in Section 8.14 (2)(B) and the management plan developed
under Section 22.1. All certificates of compliance and notices of noncompliance for new construction
and replacement must include property and property owner identification, date of inspection, system
components, system location (dimensioned or drawn to scale), well setback distance, field check of
soil conditions, SWF, as defined under part Section 2.2 (109), designations as applicable, and Class V
designation as applicable.
(4) A certificate of compliance or notice of noncompliance for new construction or replacement must be
signed by a qualified employee certified as an inspector who is authorized by the Department or local
unit of government. The certificate of compliance or notice of noncompliance for new construction
and replacement must be submitted to the owner or owner's agent within 15 days.
25 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
(5) A certificate of compliance or notice of noncompliance must include a certified statement from the
qualified employee who conducted the compliance inspection and indicate whether the SSTS is in
compliance with this Chapter.
(6) If a compliance inspection indicates that the system is not in compliance with applicable
requirements, the notice must contain a statement to this effect.
(7) Certificates of compliance for new construction or a replacement system remain valid for five years
from the date of issuance unless the Department or local unit of government finds evidence of
noncompliance.
8.14 Certificate of compliance; notice of noncompliance; existing systems.
(1) The agency's existing SSTS inspection report forms shall be used for existing system compliance
inspections.
(2) An inspection for existing SSTS must verify the conditions in subitems (A) to (C).
(A) Sewage tanks must be assessed for leakage below the operating depth. A leakage report must
be completed that includes the method or methods used to make the assessment. The
assessment must be made by either a licensed SSTS business, except a design business, or a
qualified employee with an SSTS certification, except as a designer. A passing report is valid
for three years unless the certified individual has reason to believe that a new inspection is to
be conducted and the tank is found not to be watertight.
(B) The vertical separation distance from the bottom of the soil dispersal system and the
periodically saturated soil or bedrock must be verified. This verification must be achieved by
either conducting soil borings or by prior verifications by two independent parties. The soil
borings used for system design or previous inspections qualify as a verification. A vertical
separation distance report must be completed that includes the method or methods used to
make the assessment and includes any previous soil borings. The assessment must be made
by either a licensed inspection or design business or a qualified employee inspector with
jurisdiction. If the verification separation report consists of verifications by two independent
parties, a subsequent verification is not required unless the inspector has reason to believe a
noncompliant condition exists.
(C) Sewage backup, surface seeping, or surface discharge from the system must be determined.
A hydraulic function report must be completed that includes tire method or methods used to
make the assessment. The assessment must be made by either a licensed inspection business
or a qualified employee with an inspector certification. A passing report is valid until a new
inspection is requested or if the hydraulic performance is believed to have changed.
(3) A certificate of compliance for an existing system compliance inspection shall be based on the results
of the verifications in item 2. The certificate of compliance for an existing system compliance
inspection must be signed by a licensed inspection business or a qualified employee certified as an
inspector. The certificate or notice for an existing system compliance inspection must be submitted to
the Department or local unit of government with jurisdiction and the property owner or owner's agent
no later than 15 days after a compliance inspection. The completed form must also be submitted to
the owner or ovmer's agent. The certificate of compliance for an existing system compliance
inspection is valid for three years from the date of issuance, even if one of the supporting reports
expires before the three -year period, unless an inspector finds evidence of noncompliance.
26 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
(4) If a compliance inspection for an existing system indicates that the system is noncompliant, the notice
must be signed by a licensed inspection business or qualified employee certified as an inspector and
contain a statement to that effect and specify what must be done to achieve compliance.
8.15 Periodically saturated soil disagreements.
(1) If a documented discrepancy arises on the depth of the periodically saturated soil between licensed
businesses for SSTS design or compliance purposes, all disputing parties must follow the procedure
outlined in this subpart.
(2) One or more of the methods in units (A) to (C) must be employed.
(A) Obtain an opinion from a qualified employee of the Department or local permitting authority
with jurisdiction, if the Department or Local permitting authority is willing to provide an
opinion.
(B) Obtain an opinion from an SSTS technical evaluation committee, if a committee has been
developed for this purpose and is available and willing to render an opinion. The committee
must be created in cooperation with the commissioner.
(C) Obtain an opinion from a Minnesota licensed professional soil scientist who is a certified
SSTS designer or inspector and who is independent of, and agreed upon by, both parties.
(D) If options under Section 8.15 (2)(A) or Section 8.15 (2)(B) are not viable, an opinion must be
rendered under Section 8.15 (2)(C).
(3) If opinions rendered in items Section 8.15 (1) or Section 8.15 (2) do not resolve the dispute, all initial
and follow -up documents and information generated must be submitted to the Department or local
unit of government. The Department or local unit of government shall take into consideration all
information and opinions rendered and make a final judgment. The Department or local unit of
government shall render findings of fact, conclusions of law, and findings setting forth the reasons for
any final decisions it renders.
(4) If a documented discrepancy arises on the depth of the periodically saturated soil between an SSTS
licensed business and the Department or local unit of government for SSTS design or compliance
purposes, all disputing parties shall follow the procedure outlined in this item.
(A) The Department or local unit of government and the licensed business must meet at the
disputed site in an attempt to resolve differences.
(B) If the provision in Section 8.15 (4)(A) does not resolve differences, then one or more of the
methods in Section 8.15 (2)(B) or Section 8.15 (2)(C), are allowed to be employed.
(C) If opinions in Section 8.15 (4)(B) are not sought or do not resolve the dispute, the
Department or local unit of government shall take into consideration all information and
opinions rendered and make a final judgment. The Department or local unit of government
shall render findings of fact, conclusions of law, and findings setting forth the reasons for any
final decisions they render.
(5) Upon resolution of a dispute, amendments to initial disputed documents containing the resolution
shall be made and submitted to the Department or local unit of government and all other parties
involved.
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
SECTION 9 SITE EVALUATION AND SOIL TESTING
9.1 Site evaluations consisting of preliminary and field evaluations according to parts this Section must be
conducted for all proposed sites for SSTS, including both ISTS and MSTS. The site evaluation is
considered the first phase of an SSTS design.
9.2 A preliminary evaluation for individual subsurface sewage treatment systems shall consist of determination,
location, or existence of following items:
(1) Design flow for the dwelling, dwellings, or other establishments.
(2) Proposed or existing:
(A) Water supply wells within 100 feet of the proposed SSTS;
(B) Existing and proposed buildings or improvements on the lot; and,
(C) Buried water supply pipes within 50 feet of the proposed system.
(3) Easements on the lot.
(4) The ordinary high water level of public waters, if adjacent to the lot.
(5) Floodplain designation and flooding elevation from published data or data that is acceptable to and
approved by the Department or local unit of government or the DNR, if applicable.
(6) Property lines.
(7) All required setbacks from the system.
(8) The soil characteristics at the proposed soil treatment and dispersal areas as obtained by the soil
survey report, including the soil map, map units, landscape position, parent material, flooding
potential, slope range, periodically saturated soil level, depth to bedrock, texture, color, depth to
redoximorphic features, and structure and consistence of soil horizons.
(9) A geocode or property identification number.
(10) Names of property owners.
(11) The inner wellhead management zone or wellhead protection area of a public water supply, if
applicable.
9.3 A field evaluation for an individual subsurface sewage treatment system shall consist of the following
items:
(1) Lot lines shall be confirmed in the field using the most recent document source. Lot improvements,
required setbacks, and easements must be identified.
(2) The following surface features must be described:
(A) The percent and direction of the slope of the proposed system location.
28 Washington County Development Code
Effective September 23, 2009 Chapter Four <p Subsurface Sewage Treatment System Regulations
(B) Vegetation types.
(C) Any evidence of cut or filled areas or disturbed or compacted soil.
(D) The flooding or run -on potential
(E) A geomorphic description.
9.4 For subdivision or lot approval testing, enough soil observations must be conducted to assure that suitable
soil exists for each lot for long -term sewage treatment outlining an area with enough space on the lot for
two soil treatment and dispersal areas. This tested area must be at least 10,000 square feet. Percolation
tests are not required for subdivision or lot approval testing unless the permeability cannot be estimated or
there is reason to believe the soil is not original or has been disturbed.
9.5 Complete soil testing on each individual lot must be conducted prior to permit issuance independent of any
prior subdivision or lot approval testing. For permit issuance, a minimum of four (4) soil observations
outlining an area of 5,000 square feet are required. At least one soil observation must be performed in the
portion of the soil treatment area anticipated to have the most limiting conditions. Larger areas may be
required where conditions of use, soils, topography, or vegetation require. Soil observations must comply
with the following requirements:
(1) The soil observation must be conducted within or on the borders of the proposed site;
(2) The soil observations must be performed in an exposed pit or by hand angering or probing. The use
of flight augers is not allowed.
(3) The soil observation method must allow observation of the different soil horizons that constitute the
soil profile and, if determining the loading rate by use of fable IX in Minnesota Rules Chapter
7080.2150' undisturbed soil structure must be observed.
(4) Soil observations must be conducted prior to any required percolation tests to determine whether
the soils are suitable to warrant percolation tests and, if suitable, at what depth percolation tests
shall be conducted.
(5) The minimum depth of the soil observations must be to the periodically saturated layer, to the
bedrock, or three feet below the proposed depth of the system, whichever is less.
9.6 Each soil profile observed at the proposed soil treatment and dispersal area must be evaluated under
adequate light conditions with the soil in a moist unfrozen state for the characteristics in items (1) through
(8):
(1) The depth of each soil horizon measured from the ground surface. Soil horizons are differentiated
by changes in texture, color, redoximorphic features, bedrock, structure, consistence, and any other
characteristics that affects water movement or treatment of effluent.
(2) A description of all soil colors for each horizon according to the Munsell Soil Color Charts,
Revised Edition, Munsell Color Corporation (1992), or equivalent. The color charts are
incorporated by reference, are available through the Minitex interlibrary loan system, and are not
subject to frequent change.
Effective September 23,2009 Chapter Four S• Subsurface Sewage Treatment System Regulations
(3) A description of the soil texture, and structure using the United States Department of Agriculture
(USDA) soil classification system as specified in the Field Book for Describing and Sampling
Soils, which is incorporated by reference under Section 2.2 (46).
(4) Depth to bedrock.
(5) Depth to periodically saturated soil for new construction or replacement as determined by
redoximorphic features and other indicators, as determined in subitems (A) to (C):
(A) In subsoil and parent material, redoximorphic features include:
(i) Distinct redoximorphic iron accumulation or distinct redoximorphic iron
depletions;
(ii) A gleyed or depleted soil matrix or redoximorphic mottles having a color chroma
of two or less or a depleted matrix or redoximorphic mottles having a color hue of
5Y and a chroma of three or less; or
(iii) Faint redoximorphic concentrations or faint redoximorphic depletions in subsoil or
parent material with a hue of 7.5YR or redder.
(B) In lower topsoil layers that are deeper than 12 inches from the surface and are immediately
followed in depth by a periodically saturated horizon, redoximorphic features include:
(i) Soil colors with a redoximorphic chroma of two or less; or
(ii) Redoximorphic accumulations or depletions.
(C) In the upper 12 inches of the topsoil layer immediately below which occurs a periodically
saturated horizon, the depth of seasonal saturation is determined by indicators in units (i) to
(v):
(i) Soil colors with a chrome of zero;
(ii) Organic soil textures or mineral soil textures with an organic modifier;
(iii) Dominance of hydrophytic vegetation;
(iv) The soil treatment area at or near the elevation of the ordinary high water level of a
surface water or in a concave hill slope position; or
(v) Redoximorphic accumulations or depletions.
(6) Depth to periodically saturated soil for all existing systems, determined by redoximorphic features
in item (5), except subitems (B), unit (i), and (C), units (i), (iii), and (iv), as measured outside the
area of the system influence in an area of similar soil.
(7) Depth of standing water in the soil observation excavation, measured from the soil surface, if
observed.
30 Washington County Development Code
Effective September 23, 2009 Chapter Four <• Subsurface Sewage Treatment System Regulations
(8) Any other soil characteristics that needs to be described to design a system, such as hardpans or
restrictive layers. These other characteristics must be classified according to the Field Book for
Describing and Sampling; Soils, which is incorporated by reference under Section
9.7 The effluent loading and absorption area size must be determined by either item (1) or (2).
(1) The loading rate based on an examination of soil texture, undisturbed structure, and consistence at
the most limiting layer within 12 inches below the proposed absorption area using the United States
Department of Agriculture (USDA) soil classification system as specified in the Field Book for
Describing and Sampling Soils, which is incorporated by reference under Section 2.2 (46); or
(2) The loading rate based on the percolation procedure described in subitems (A) to (H).
(A) Each test hole must be six to eight inches in diameter, have vertical sides, and be located at
the depth of the proposed soil absorption area. For mounds and at -grade systems, the bottom
of each test hole must be in the upper 12 inches of the original soil. For trenches and seepage
beds, the bottom of each test hole shall be at the depth of the absorption area;
(B) Soil texture descriptions for percolation test holes must note the depths from the ground
surface where texture changes occur;
(C) The bottom and sides of the hole must be carefully scratched to remove any smearing and to
provide a natural soil surface into which water penetrates. The scarification must not result in
the hole having a diameter of greater than eight inches;
(D) All loose material must be removed from the bottom of the test hole and two inches of one-
fourth to three - fourths inch gravel or clean sand must be added to protect the bottom from
scouring;
(E) The hole must be carefully filled with clear water to a minimum depth of 12 inches from the
bottom of the test hole and maintained for no less than four hours for saturation to occur. The
soil must then be allowed to swell for at least 16, but no more than 30, hours. In sandy soils,
the saturation and swelling procedure is not required and the test is allowed to proceed if the
initial filling of the hole with 12 inches of water seeps away in less than ten minutes;
(F) In sandy soils, water depth must be adjusted to eight inches over the soil at the bottom of the
test hole. From a fixed reference point, the drop in water level must be measured in inches to
the nearest 1/16 inch at approximately ten - minute intervals. A measurement is also allowed
to be made by determining the time it takes for the water level to drop one inch from an eight
inch reference point. If eight inches of water seeps away in less than ten minutes, a shorter
interval between measurements must be used, but water depth must not exceed eight inches.
The test must continue until three consecutive percolation rate measurements do not vary by
more than ten percent. In other soils, the water depth must be adjusted to eight inches over
the soil at the bottom of the test hole. From a fixed reference point, the drop in water level
must be measured in inches to the nearest 1/16 inch at approximately 30- minute intervals and
refilled between measurements to maintain an eight inch starting head. If water seeps away
in less than 30 minutes, a shorter time interval between measurements must be used, but
water depth must not exceed eight inches. The test must continue until three consecutive
percolation rate measurements do not vary by more than ten percent. The percolation rate is
also allowed to be determined by observing the time it takes the water level to drop one inch
from an eight -inch reference point if a constant water depth of at least eight inches has been
maintained for at least four hours prior to the measurement;
31 Washington County Development Code
Effective September 23, 2009 Chapter Four d. Subsurface Sewage Treatment System Regulations
(G) The time interval must be divided in minutes by the drop in water level in inches to obtain the
percolation rate in minutes per inch. The percolation rates that are within the ten percent
provision determined for each test hole must be averaged to determine the final percolation
rate for that hole. The slowest final percolation rate for all holes within the soil dispersal area
must be used for design; and
(1-1) A percolation test must not be run where frost exists within 12 inches of the bottom of the
percolation test hole.
9.8 A written report on the site evaluation for an individual subsurface sewage treatment system must be
prepared and include the following:
(1) Preliminary and field evaluation results from Sections 9.2 through 9_6.
(2) Dates of preliminary and field evaluations.
(3) A map drawn to scale or dimension, with a north arrow, and including:
(A) horizontal and vertical reference points of the proposed soil treatment and dispersal areas,
soil observations, percolation tests, and pertinent distance from the proposed SSTS to all
required setbacks, lot improvements, easements, ordinary high water mark of public waters,
property lines, and direction and percent slope.
(B) the location of any unsuitable, disturbed, or compacted areas.
(C) the access route for system maintenance.
(4) The estimated depth of periodically saturated soil layer, bedrock, or flood elevation, if appropriate.
(5) The proposed elevation of the bottom of the soil treatment and dispersal system.
(6) Anticipated construction related issues.
(7) The name, address, telephone number, and certified statement of the individual conducting the site
evaluation.
(8) An assessment of how known or reasonably foreseeable land use changes are expected to affect
system performance, including, but not limited to, changes in drainage patterns, increased
impervious surfaces, and proximity of new water supply wells.
(9) A narrative explaining any difficulties encountered during the site evaluation, including, but not
limited to, identifying and interpreting soil and landfoim features and how the difficulties were
resolved.
(10) A notation of any differences between observed soil characteristics and those identified in the soil
survey report.
9.9 Applicants for subsurface sewage treatment system permits, site approvals or subdivision approvals will be
required to submit soil test data from soil borings and percolation tests, or soil pits, for each proposed site or
installation. The minimum testing shall be that necessary to verify suitable conditions for two complete soil
dispersal and treatment areas.
32 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
9.10 All soil testing shall be conducted in accordance with the requirements of this Chapter and shall be
conducted by appropriately licensed businesses and certified individuals in accordance with Minnesota
Rules, Chapter 7083.
9.11 Prior to and during construction or lot improvements, the proposed initial and replacement soil treatment
and dispersal areas shall be protected from disturbance, compaction, or other damage by use of stakes and
silt fence or snow fence.
9.12 Underground utilities must be located before soil observations are undertaken. Required safety precautions
must be taken before entering soil observation pits.
9.13 Where soil tests require a mound, testing and design must clearly show suitable area for installation of two
(2) complete mounds. Where site conditions are such that the only backup mound will likely be disturbed,
the Department, at its discretion, may require both mounds to be constructed at once.
9.14 Designs for new construction or replacement SSTS must comply with all applicable requirements and any
other applicable codes, Hiles, and laws.
33 Washington County Development Code
Effective September 23, 2009 Chapter Four 6• Subsurface Sewage Treatment System Regulations
SECTION 10 MSTS SITE EVALUATION AND SOIL TESTING
10.1 Soil and site evaluations must be conducted for MSTS design. The evaluations must be conducted according
to this Section and Section 9 of this Chapter. Evaluations must identify and delineate an initial and
replacement soil treatment and dispersal area with appropriate system boundaries.
10.2 A preliminary evaluation for midsized subsurface sewage treatment systems shall consist of determining:
(1) The design flow and anticipated effluent concentrations of biochemical oxygen demand, total
suspended solids, and fats, oils, and grease, and inputs of non - domestic waste.
(2) Whether the location of water supply wells impacts the location of the system due to setback
constraints.
(3) Whether building improvements will be within 50 feet of the proposed soil treatment and dispersal
area.
(4) Whether buried water supply pipes will be within 50 feet of the proposed system.
(5) Whether easements will be within 50 feet of the proposed system.
(6) Whether the ordinary high water level of public waters will be within 500 feet of the proposed soil
treatment and dispersal area and if so, a preliminary assessment of phosphorus impacts to the
surface water.
(7) Whether the system will be located in a floodplain and the system location in relation to the 100 -
year flooding elevation from published data if available or data that is acceptable to the Department
or local unit of government.
(8) The required setbacks from the proposed soil treatment and dispersal system.
(9) The soil survey information on the proposed soil dispersal area, including the soil map, map units,
landscape position, parent material, flooding potential, slope range, periodically saturated soil level,
depth to bedrock, texture, color, and structure of soil horizons, and permeability of soil horizons.
(10) A geocode or property identification number.
(11) The names of the property owners; and
(12) The location of the system on a United States Geological Survey quadrangle map of the proposed
soil treatment and dispersal area and the area within one mile.
10.3 Before conducting a field evaluation, the designer shall confer with the Department or local unit of
government to determine the requirements and scope of the evaluation, dependent upon system size, soil
conditions, and other applicable factors. At a minimum, the requirements in this Section must be met:
(1) Property lines must be confirmed in the field using the most recent document source. Site
improvements, required setbacks, and easements must be identified, located, and marked.
(2) A general evaluation and description of the proposed soil dispersal area, including a general
geomorphic description, current land use, and past land use, if known, must be provided.
34 Washington County Development Code
Effective September 23, 2009 Chapter Four d• Subsurface Sewage Treatment System Regulations
(3) The following surface features must be identified and described:
(A) The dominant vegetation.
(B) Evidence of disturbed or compacted soil or flooding or run -on potential.
(C) Landscape position, including landform, slope gradient, slope direction, and surface
morphometry as described in the Field Book for Describing and Sampling Soils Version
2_0 September 2002, developed by the National Soil Survey Center and Natural Resources
Conservation Service of the United States Department of Agriculture. The field book is
incorporated by reference, is not subject to frequent change, and is available through the
Minitex interlibrary loan system.
10.4 The required number of soil pits to adequately characterize the soil on the proposed site must be determined
by the professional judgment of the designer as based on the size of the area, consistency of the soil, and
approved by the Department or local unit of government.
10.5 The qualifying soil observation pits to be used for the MSTS design must be located on or near the borders
of the proposed soil treatment and dispersal area. Soil observation pits must be dug outside the soil
dispersal area, if possible. The soil must be observed and described to a depth of at least three feet below
the proposed depth of the system. Other soil observation pits are allowed to supplement the required soil
observation pit information.
10.6 Underground utilities must be located before soil observations are undertaken. Required safety precautions
must be taken before entering soil observation pits.
10.7 The following soil observations must be made:
(1) The soil properties and features described in items (A) to (M) must be described according to the
Field Book for Describing and Sampling Soils, which is incorporated by reference under Section
2.2 (461.
(A)
Matrix soil color.
(B)
Soil features that have different colors from the matrix color, including, but not limited to,
clay films, organic stains, silt coats, nodules, and concretions.
(C)
Abundance, size, color, and contrast of redoximorphic features.
(D)
Soil texture, with modifiers.
(E)
Grade, size, and shape of soil structure.
(F)
Moist soil consistence.
(G)
Abundance and size of rock fragments.
(H)
Abundance and size of roots.
(I)
Horizon boundary conditions.
(.1)
Parent materials.
35
Washington County Development Code
Effective September 23, 2009 Chapter Four -*. Subsurface Sewage Treatment System Regulations
(K) Pores, quantity and size.
(L) Quantity of boulders and tree stumps affecting construction.
(M) Any other characteristics of feature that affects permeability of the soil or treatment of
sewage effluent.
(2) The depth to bedrock, if encountered, must be determined by the requirements in Section 2.2 (9).
(3) The elevation of standing water evident in any soil pit must be identified.
(4) The soil must not be described when frozen, at improper moisture content, or under poor light
conditions.
10.8 Hydraulic conductivity testing of the soil must be employed, along with a determination of the soil's
texture, structure and consistence, to determine the loading rate of effluent in the soil. The frequency of
observations and measurements must be determined by the professional judgment of the designer,
dependent on the variation in soil conditions and the system size, with the frequency of the observations and
measurements approved by the Department or local unit of government.
10.9 All field soil information gathered must be compared with soil survey information. Any discrepancies shall
be identified.
10.10 Site and soil information gathered in Section 10.2 through Section 10.9 must be interpreted for suitability
for MSTS siting, design, and construction, with consideration of the following:
(1) Surface features impacts from precipitation, run -on, and imerflow or any other item that could have
potential to adversely impact the ability of the soil to accept water.
(2) Cultural features, including, but not limited to, setbacks and easements.
(3) Site conditions affecting system layout, distribution system requirements, and constmetability.
(4) Layers of coarse soil textures that affect treatment.
(5) Disturbed, compacted, cut - filled, or other unnatural condition, if present.
(6) The uniformity of the soil over the site.
(7) Future surrounding land use changes.
(8) Soil sizing factor or loading rate.
(9) An approximation of the rise in groundwater from system operations as determined by a
groundwater mounding assessment. A narrative evaluation of the accuracy of the approximation
must be provided. The approximation must be related to the requirements in Section 16.5 (7).
10.11 Systems proposed to be located in flood fringes must determine feasibility of relocating the system outside
the floodplain.
36 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
10.12 The limiting layer in the soil shall be determined based on the depth of bedrock or periodically saturated
soil if encountered. The depth of periodically saturated soil shall be determined according to Section 9.6
L5), and the depth to bedrock shall be as defined in Section 2.2 (9).
10.13 The proposed soil treatment and dispersal areas shall be protected from disturbance, compaction, or other
damage by use of stakes and silt fence or snow fence.
10.14 All information gathered in Section 10.2 through Section 10.12 must be submitted for review and approved
by the Department or local unit of government prior to final design. The submittal must also contain:
(1) A map of the proposed soil dispersal area, drawn to scale, showing:
(A) Features with a setback within 150 feet of the system.
(B) Easements within 50 feet of the system.
(C) Floodplains, wetlands, and surface waters, within 100 feet of the system.
(D) Location and elevation of all soil pits, borings, and hydraulic tests.
(E) Two -foot contour lines.
(2) Dates and weather conditions during the field evaluations.
(3) Elevations of the periodically saturated soil or bedrock.
(4) Proposed depths of the system bottom.
(5) Proposed soil loading rate.
(6) System site boundaries.
(7) Anticipated construction related issues.
(8) The name, address, telephone number, and certified statement of the individual conducting the site
evaluation.
(9) A narrative explaining any difficulties encountered during the site evaluation, including, but not
limited to, identifying and interpreting soil and landform features and how the difficulties were
resolved.
37 Washington County Development Code
Effective September 23, 2009 Chapter Four -I- Subsurface Sewage Treatment System Regulations
SECTION 11 GROUNDWATER INVESTIGATION
11.1 A preliminary groundwater assessment for nitrogen impacts to aquifers must be conducted for all proposed
MSTS according to this Section.
11.2 The following information must be ascertained from the best available information:
(1) The size of the soil dispersal system, proposed loading rate, and system geometry.
(2) The geocode(s) or parcel identification number(s) of the parcel(s) where the proposed soil dispersal
area is to be located.
(3) Any anticipated discharges from nondomestic sources to the proposed MSTS.
(4) The location of the MSTS on a United States Geological Survey quadrangle topographic map,
including the area within a one -mile radius of the proposed soil treatment system.
(5) A determination of the general geology, periodic soil saturation, regional groundwater setting, and
aquifers used for water supply and a description of the general site hydrology characteristics,
including, but not limited to, identification and estimated depth measurements to geologic units and
aquifers, and identification of groundwater confining strata.
(6) A determination whether the proposed system is in a drinking water supply management area, inner
wellhead management zone, source water protection area, groundwater sensitive area, or a special
well construction area.
(7) An assessment of all water supply wells within a 300 -foot radius of the proposed soil treatment area
with a minimum assessment of well locations and casing depths from well construction log records.
If no records exist, the well locations and casing depths must be estimated.
(8) A determination or estimation of groundwater flow direction
(9) An assessment of pathogenic organism, nitrogen, and phosphorus impacts from the system.
11.3 The designer must consult with the Department or local unit of government to determine whether the
Department or local unit of government will require a field or further groundwater investigation and, if so, the
extent of the investigation. The field or further investigation must be conducted if information gained in
Section 11.2 indicates that a proposed system is a potential contaminant threat to a regional water table, an
aquifer, water supply well(s), or surface waters. The threats of concern include, but are not limited to, fecal
organism contamination, nitrate contamination, or phosphorus impacts to surface waters.
11.4 The designer must consult with the Department or local unit of government to determine if the Department or
local unit of government will require effluent or groundwater monitoring and, if so, the extent of the
monitoring. Monitoring must be conducted if information gained in Section 11.2 and 113 indicates that a
proposed system is a potential contaminant threat to a regional water table, an aquifer, or a water supply well
or impacts surface waters. The groundwater mound height must be monitored under all MSTS during
operation.
11.5 The information gathered in this part must be used to estimate or measure if the system adequately protects the
groundwater and surface water as prescribed in part Section 4.9. The interpretation must include an
evaluation of whether contaminant plumes will intersect water supply well capture zones.
38 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
11.6 All information required in this part must be submitted for review and approval of the Department or local
unit of government prior to final design, including all applicable information delineated on a map.
39 Washington County Development Code
Effective September 23, 2009 Chapter Four B• Subsurface Sewage Treatment System Regulations
SECTION 12 SEWAGE FLOW DETERMINATION
12.1 Completion of tasks outlined in Section 12 to Section 21 is considered the second phase of SSTS design.
12.2 The estimated design flow for any dwelling must provide for at least two (2) bedrooms. For multiple or
multifamily dwellings, the design flow consists of the sum of the design flows for each individual unit.
12.3 The estimated design flow for dwellings is based on Table I, which is based on calculating the number of
bedrooms by 150 gallons per day.
Table I
2 300
3 450
4 600
5 750
6 900
12.4 The design flow for MSTS serving existing dwellings is determined by the following calculation in
conjunction with Section 12.3:
Total flow from the ten highest flow dwellings + (total flow from the remaining dwellings X 0.45)
12.5 For new housing developments, the developer shall determine and restrict the total number of bedrooms for
the development and determine the design flow by multiplying the total number of bedrooms by 110
gallons per day. If the ultimate development of phased or segmented growth meets or exceeds 10,000
gallons per day, the initial system or systems and all subsequent systems require a state disposal system
permit.
12.6 If construction of additional dwellings or bedrooms, installation of water -using devices, or other factors
likely to increase the flow volumes can be reasonably anticipated, the SSTS must be designed to
accommodate the additional capacity as determined by the Department or local unit of government.
12.7 Design sewage flow for other establishments are determined by methods in item (1) or (2):
(1) The design flow of sewage for MSTS serving other establishments is estimated using Table II.
(2) The measured design flow of sewage for MSTS serving other establishments is determined by
averaging the measured daily flows for a consecutive seven -day period in which the establishment
is at maximum capacity or use.
40 Washington County Development Code
Effective September 23, 2009 Chapter Four 4• Subsurface Sewage Treatment System Regulations
I able 11— Estimated Design Sewage Flow from Other Establishments
�iveiligttris
also,.seenutdorir.''
ecreaitoltJtttt..
�?
., ., :s;
> w 7esign Flaw
allQns %tla+mt
Hotel or luxury hotel
Guest
55
Square Foot
0.28
Motel
Guest
38
Square Foot
0.33
Rooming House
Resident
45
Add for each non- resident meal
3.3
Da care (no meals)
Child
19
Daycare (with meals)
Child
23
Dormitory
Person
43
Labor Carap
Person
18
Labor Cam , semi ermanent
Person
50
iL'.63e" -p
Retail Store
Square Foot
0.13
Customer
3.8
Toilet
590
Shopping Center
Employee
11.5
S uare Foot
0.15
Parking Space
2.5
Office
Em loyees /8 -Hour Shift
18
Square Foot
0.18
Medical Office*
Square Foot
1.1
Practitioner
275
Patient
8
Industrial Buildine
Em to ees /8 -Hour Shift
17.5
Employees/8-Hour Shift with Showers
25
Laundromat
Machine
635
Load
52.5
Square Foot
2 6
Barber Shop
Char
68
Beauty Salon
Station
285
Flea Market
Nonfood vendor/sl2ace
15
Limited food vender/space
25
With food vendor /space
50
Eatingand,- Mrhiciug
Establishments`
Restaurant (does not include bar or
lounge)
_ <; I7ru't .: �
Meal without alcoholic drinks
90 4v
{ a3lons)da funtt) ':
3.5
Meal with alcoholic drinks (open 16 hours or
Less)
8
Seat (open 16 hours or less)
30
Seat (open more than 16 hours)
50
Seat (open 16 hours or less, single service
articles)
20
Seat (open more than 16 hours, single service
articles
35
Restaurant — short order
Customer
7
Restaurant — dr ve -in
Car Space
30
41 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
7"�ian��a?cg�
wor
3�gy 7
Restaurant — carry out, including
caterers
Square Foot
0.5
Institution Meals
Meal
5.0
Food Outlet
Square Foot
0.2
Dining Hall
Meal
8.5
Coffee Shop
Customer
7
Cafeteria
Customer
2.5
Bar or lounge (no meals)
Customer
4.5
Seat
36
a
ISM
Drive -in Theater
Drive-in
Car Stall
5
Theater /Auditorium
Seat
4.5
Bowling Alley
Alley
185
Country Club
Member (no meals )
22
Member (with meals and showers)
118
Member (resident)
86
Fairground and Other Similar
Gatherings
Visitor
1.5
Stadium
Seat
5
Dance Hall
Person
6
Health Club /Gym
Member
35
81<C
,:�.'�''.,,
Campground
Person with hook-up
36
Site with hook-up
100
Site without hook -up, with central bath
62
Site to be served by dump station
14.5
Permanent Mobile Home
Mobile Home
225
Camp, day without meals
Person
20
Camp, day and night with meals
Person
45
Resort/Lodge Hotel
Person
62
Cabin, resort
Person
50
Retail Resort Store
Customer
4
Park or Swimming Pool
Guest
10
Visitor Center
Visitor
13
Gas Station/Convenience Store
. Customer
15
Service Station*
Customer
11
Service Bay
50
Toilet
250
Square Foot
0.25
Car wash *(does not include car
wash water)
Square Foot
5
Airport, Bus Station, Rail Depot
Passen er
5
S uare Foot
5
Restroom
565
42 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
* Waste other than sewage is only allowed to be discharged into the system if the waste is suitable to be discharged
to groundwater.
12.8 Unless otherwise noted in Table II, the flow values do not include flows generated by employees. A flow
value of 15 gallons per employee per eight hour shift must be added to the flow amount for determining the
design flow for other establishments.
12.9 Design flow determination for establishments not listed in Table 11 shall be determined by the base
available information and approved by the Department or by the local unit of government.
12.10 The measured flow of sewage for existing other establishments may be used to modify estimated flow
values determined in this part if the length and frequency of the measured flow accurately represents the
annual average water use, along with the peak weekly and daily water use.
12.11 The design flow for MSTS must also include 200 gallons of infiltration and inflow per inch of collection
pipe diameter per mile per day with a minimum pipe diameter of two inches to be used for the calculation.
Flow values are allowed to be further increased if the system employs treatment devices that are exposed to
atmospheric conditions that will infiltrate precipitation. Flow estimates as calculated in this Chapter shall
not be relied upon for the design of collection systems.
12.12 If concentrations of biochemical oxygen demand, total suspended solids, and oil and grease from the
sewage are expected to be higher than 175 mg/L, 65 mg/L, or 25 mg /L, respectively, an estimated or
measured average concentration must be determined and be acceptable to the Department or local unit of
government. System design must account for concentrations of these constituents so as to not cause
internal system malfunction, such as, but not limited to, clogging of pipes, orifices, treatment devices, or
media.
43 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regutations
SECTION 13 SEWAGE TANKS
13.1 Sewage tanks serving SSTS must meet or exceed the applicable requirements of this Section unless
otherwise approved by a Minnesota licensed professional engineer and approved by the Department or the
local unit of government.
13.2 Tanks, fittings, risers, and apertures must:
(1) Be capable of supporting long -term vertical loads for the conditions in which the tank will be
placed. These loads ,include, but are not limited to, saturated soil load, based on 130 pounds per
cubic foot.
(2) Be capable of withstanding a lateral load for the conditions the tank will be placed.
(3) With proper maintenance and venting, not be subject to failure due to corrosion and degradation
from sewage or sewage gases, including risers and maintenance hole covers.
(4) Be structurally capable of withstanding exposure and stresses from freezing conditions.
13.3 Poured in place concrete tanks must be designed to meet each requirement in Section 13.2, and be designed
by a Minnesota licensed professional engineer.
13.4 Septic tanks must:
(1) Have a liquid depth of at least 30 inches. Any liquid depth that is greater than 84 inches must not
be used when calculating the septic tank liquid capacity.
(2) Have a minimum of six feet between the inlet and outlet of the tank, rather than between
compartments, or have a minimum of six feet from the inlet of the first tank to the outlet of the last
tank in series.
(3) If site conditions warrant, the inlet and outlet are allowed to be located on walls that are not
opposite each other along axis of the maximum dimension; however, the requirements of Section
13.4(2 must be met.
(4) Have an inlet invert at least two inches above the outlet invert.
(5) Have a reserve or storage space between the liquid surface and the top of the inlet and outlet baffles
of not less than eight inches or 100 gallons, whichever is greater.
13.5 For dwellings, there shall be two (2) septic tanks in series with the liquid capacity based on the number of
bedrooms in the dwelling; such tanks shall be as large as the capacities in Table III. The only exception to
this requirement is for the upgrade of an existing compliant system if the primary tank capacity is met and
there is no garbage disposal or sewage pump. System replacement shall require two (2) tanks in series.
44 Washington County Development Code
Effective September 23, 2009 Chapter Four Z• Subsurface Sewage Treatment System Regulations
Table III– Minimum Septic Tnnk Cannrity
..
..= ..:-�'1'32iCK,0i31YL% „?;
'�`-'= '8n�t�,•°^*,z',�-
Two or less
1,000
500
Three
1,000
1,000
Four to Five
1,500
1,000
Six to Seven
2,000
1,000
Eight to Nine
2,500
1,250
Ten or More
Septic tank shall be sized as an MSTS with the second
tank in series being at least 50 percent of the capacity of
the first tank
Multiple Family Dwelling
—containing two or more its
Size shall be the sum of the individual dwelling unit
requirements.
13.6 An effluent screen with an alarm must be installed on the outlet of the last tank in series.
13.7 Septic tanks must be connected in series. Each tank or compartment must contain at least 25 percent of the
required total liquid capacity. The first tank must be equal to or larger than any subsequent tank in the
series.
13.8 Septic tank liquid capacity prior to other treatment devices must accord with the manufacturer's
requirements, accepted engineering principles, or as identified in the product registration recommended
standards and criteria.
13.9 If septic tanks are compartmentalized, (1) to (5) of this Section apply:
(1) When septic tanks are divided into compartments, the volume of the first compartment must be
equal to or larger than any succeeding compartments. Each compartment must contain at least 25
percent of the total required liquid capacity and have an inside horizontal dimension of at least 24
inches.
(2) Flow between compartments can be achieved by an unbaffled transfer hole with a minimum size of
50 square inches located in the clarified liquid zone or a minimum of 12- square inch transfer hole
located above the clarified liquid zone that is baffled according to Section 13.11. The final
compartment of a tank that employs a transfer hole in the clarified zone shall not be used as a pump
tank.
(3) Septic tanks must have at least a two -inch drop between the invert of the inlet to the invert of the
outlet. No liquid level drop is required between two compartments.
(4) Adequate venting must be provided between compartments by baffles or by an opening of at least
12 square inches near the top of the compartment wall.
(5) All compartmental walls must be designed to withstand the weight of the effluent against an empty
compartment.
13.10 All septic tanks must be baffled according to (1) to (7) of this Section. Effluent screens are allowed to be
substituted for outlet baffles.
(1) Baffles roust be installed at each inlet and outlet of septic tanks. Outlet baffles are required on
compartment walls if the transfer hole is at the liquid level.
45 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
(2) Baffles must be resistant to corrosion or decay. Inlet baffles must not restrict the movement of
solids.
(3) Baffles must be integrally cast with the tank or affixed at the top and bottom with connectors that
are not subject to corrosion or decay. Baffles for fiberglass reinforced polyester tanks are allowed
to be either resin bonded or secured with suitable structural adhesive. Sanitary tees used as baffles
must be affixed to the inlet or outlet pipes with a permanent waterproof adhesive.
(4) The inlet baffle must extend at least six inches, but not more than 20 percent of the total liquid
depth, below the liquid surface and at least six inches above the liquid surface.
(5) The outlet baffle and any baffles between compartments must extend below the liquid surface a
distance equal to 40 percent of the liquid depth, except that the penetration of the indicated baffles
or sanitary tees for horizontal cylindrical tanks must be 35 percent of the total liquid depth. They
must also extend above the liquid surface as required in Section 13.10 (4).
(6) There must be at least one inch between the underside of the top of the tank and the highest point of
the inlet and outlet baffles.
(7) The nearest point on the inlet baffles other than sanitary tees must be no less than 6 inches and no
more than 12 inches from the end of the inlet pipe. The nearest point on the outlet baffle, other than
sanitary tees, must not be closer than 6 inches and no more than 12 inches from the beginning of the
outlet pipe of the baffle. Sanitary tees used as inlet or outlet baffles must be at Least 4 inches in
diameter.
13.11 Septic tanks shall have a minimum of two maintenance holes with a minimum diameter of 20 inches (least
dimension). One maintenance hole must be over the outlet device (baffles or screen). Another maintenance
hole must be either above the inlet device, or near the center of the tank, and facilitate pumping without
interference. Enough maintenance holes must be provided so access can be gained within six feet of all walls
for solids removal of each compartment. Six-inch inspection pipes shall be provided over any baffles that do
not have access maintenance holes.
1112 All maintenance hole risers must extend through the tank cover above final grade.
13.13 Covers for maintenance holes must:
(1) Be secured by being locked, being bolted or screwed, having a weight of at least 95 pounds, or other
methods approved by the Department or local unit of government. Covers shall also be leak resistant;
and be designed so the cover cannot be slid or flipped, which could allow unauthorized access to the
tank.
(2) Have a written and graphic label warning of the hazardous conditions inside the tank.
(3) Be capable of withstanding a load that the cover is anticipated to receive.
(4) Be made of a material suitable for outdoor use and resistant to ultraviolet degradation.
13.14 A secondary method to control unauthorized access must be provided.
13.15 All precast reinforced concrete sewage tanks must be constructed to meet the requirements of this chapter.
Information on best practices for tank construction is found in the National Precast Concrete Association's
best practices manual, Precast Concrete On -site Wastewater Tanks (2005). This manual is incorporated by
46 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
reference, is available through the Minitex interlibrary loan system, and is not subject to frequent change. If a
conflict exists between the manual and this chapter, this chapter applies.
13.16 All fiberglass - reinforced polyester and polyethylene tanks must be constructed to meet the requirements of
this chapter. Information on best practices for these tanks is found in the International Association of
Plumbing and Mechanical Officials (IAPMO), Material and Property Standard for Prefabricated Septic Tanks,
Standard PS 1 -2006 (2006). This standard is incorporated by reference, is available through the Minnex
interlibrary loan system, and is not subject to frequent change. If conflicts exist between the standard and this
chapter, this chapter applies.
13.17 Precast reinforced concrete tanks must:
(1) Have a method to lift the tank for an ultimate Load that is four times the working load.
(2) Undergo proper curing to achieve a compressive strength of 4,000 pounds per square inch before
transport, placement, or use.
(3) Have no pipe penetration points or openings in the exterior walls or tank bottom below the tank liquid
level, unless designed for a specific operational purpose and approved by the Department or local unit
of government.
13.18 Fiberglass- reinforced polyester or polyethylene tanks must be protected against deterioration during storage.
13.19 Location and installation of tanks:
(1) Sewage tanks must not be placed in areas that prohibit the removal of solids and liquids from the tank
according to Section 22.
(2) Sewage tank's must be set back as specified in Table V in Section 16.
(3) The top of sewage tanks must not be buried deeper than four feet from final grade for new dwellings,
or the tank manufacturer's maximum designed depth for the tank. The minimum depth of soil cover
over the insulation on the top of the tank is six inches.
(4) Sewage tanks must not be placed in floodways, drainageways, or swales. Upslope drainage must be
diverted away from the location of all tanks. A tank's final cover must be crowned or sloped to shed
surface water.
(5) Sewage tanks must not be placed in areas subject to vehicular traffic unless engineered for the
anticipated load.
(6) Sewage tanks must be placed on firm and evenly compacted soil and with the soil level in all
directions. The bottom shall be excavated in a manner so the vertical load is borne by the tank walls
and not the tank bottom. If the bottom of the tank excavation contains rocks, bedding material must
be used according to manufacturer's instructions. The soil beneath the tank must be capable of
bearing the weight of the tank and its contents.
(7) Sewage tanks and risers must be installed according to manufacturer's requirements and in a
structurally sound and watertight fashion.
47 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
(8) If the top of a sewage tank is to be less than two feet from final grade, the lid of the tank must be
insulated to an R -value of ten. Maintenance hole covers must be insulated to an R -value of ten. All
insulating materials must be resistant to water absorption.
(9) Sewage tanks placed below the level of the periodically saturated soil must employ a method to
protect against flotation under periodic saturated soil conditions when the tank is empty.
(10) Connections between the concrete tank and the building sewer or supply pipe must meet the
requirements of American Society for Testing and Materials, Standard Specification for Resilient
Connectors Between Reinforced Concrete Manhole Structures, Pipes, and Laterals, ASTM C923
(2002), or equivalent. The standard is incorporated by reference, is available through the Minitex
interlibrary loan system, and is not subject to frequent change.
(11) Joints of concrete tanks, concrete tank lids, and concrete risers must be sealed using a bonding
compound that meets American Society for Testing and Materials, Standard Specification for Joints
for Concrete Pipe, Manholes, and Precast Box Sections Using Preformed Flexible Joint Sealants,
ASTM C990 (2003). The standard is incorporated by reference, is available through the Minitex
interlibrary loan system, and is not subject to frequent change.
13.20 All septic tanks must be assessed in accordance with Minnesota Rules, Chanter 7080.2010.
13.21 Tanks must be identified in accordance with the following:
(1) Sewage tanks must be marked near the outlet with:
(A)
The manufacturer's name.
(B)
The model number.
(C)
The liquid capacity.
(D)
The date of manufacture.
(E)
The maximum depth of burial.
(2) The tank manufacturer or manufacturer's agent shall provide the information in Section 13.20 to the
installer in writing.
(3) The tank inlet or outlet must be clearly marked.
(4) The installer shall submit the information in Section 13.20 with the as -built drawing.
13.22 Sewage tanks must meet the requirements in parts 7080.1910 to 7080.20202 by February 4, 2011. Tanks
produced and installed prior to February 4, 2011 must meet the requirements of Minnesota Rules 2005, part
7080.0130.
Sewage Tanks for MSTS
13.23 All holding or treatment tanks or vessels, including lined vessels and grease interceptors serving MSTS,
must conform to the applicable requirements of this Section, except as modified in Section 13.23 through
13.27, or as designed by a professional engineer and approved by the Department or local unit of
government.
48 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
13.24 Septic tank capacity for MSTS or Other Establishments shall be determined by:
(1) Total septic tank liquid capacity for a common tank serving multiple dwellings under gravity flow
to the common tank is determined by multiplying the design flow by 3.0.
(2) Total septic tank liquid capacity for a common tank serving multiple dwellings under pressure flow
to the common tank is determined by multiplying the design flow by 4.0.
(3) Common multiple septic tanks must be connected in series. Individual tanks connected in series or
any compartment of a tank must have a capacity of more than one -fourth of the required to total
liquid capacity.
(4) For MSTS that have individual septic tanks at each dwelling, the individual tanks must meet the
requirements of Section 13.5.
(5) 'dotal septic tank liquid capacity prior to other treatment devices shall be according to
manufacturer's requirements or accepted standards.
(6) Holding tanks serving Other Establishments must provide storage of at least five times the design
flow.
(7) Effluent screens must be used on the outlet baffle on the final septic tank or pressure filters must be
used in the pump tank if common tanks are employed in series. Alarms must be employed on tanks
equipped with effluent screens. Lint filters are recommended if the sewage contains laundry waste.
13.25 For common septic tanks, the liquid depth of septic tanks to determine liquid capacity must be no greater
than 84 inches. The length -to -width ratio and the length -to -depth ratio must facilitate settling of solids.
13.26 For common septic tanks, the space in the tank between the liquid surface and the top of the inlet and outlet
baffles must not be less than 20 percent of the total required liquid capacity.
13.27 All tanks used for MSTS must be tested for watertightness in accordance with Minnesota Rules, Chapter
7080.2010_ Subn. (3). The test shall be conducted to include the watertightness of all connections and
risers.
13.28 Liners used as watertight barriers for treatment devices must be designed and constructed according to liner
requirements developed by the Commissioner of the Minnesota Pollution Control Agency. If conflicts exist
between this Chapter and those requirements, this Chapter applies. Compacted soil liners must not be used
as watertight barriers for treatment devices. Liners must be tested and must hold water without loss for 24
hours after being filled to the top of the liner.
13.29 A commercial or institutional food preparation facility such as, but not limited to, a restaurant, cafeteria, or
institutional kitchen, served by a system regulated under this Chapter, the system design for which was
submitted to the Department or local unit of government after the effective date of this Chapter, shall install
an external grease interceptor, unless other grease control measures are taken and approved by the
Department or local unit of government.
49 Washington County Development Code
Effective September 23, 2009 Chapter Four :> Subsurface Sewage Treatment System Regulations
SECTION 14 DISTRIBUTION OF EFFLUENT
14.1 Distribution of effluent for SSTS must meet or exceed the requirements of this Section and Minnesota
Rules, Chapter 7080.20503.
14.2 The supply pipe extending from the septic tank to the undisturbed soil beyond the tank excavation must
meet the strength requirements of American Society for Testing and Materials (ASTM), Schedule 40 Pipe,
contained in Standard Specifications for Poly(Vinyl Chloride)(PVC) Plastic Pipe, Schedule 40, 80, 120,
ASTM D1785 (2006). The schedule is incorporated by reference, is available through the Minitex
interlibrary loan system, and is not subject to frequent change.
14.3 Supply pipes must:
(1) Be made from materials resistant to breakdown from sewage and soil.
(2) Be watertight, including all joints.
(3) Be durable throughout the design life.
(4) Not deflect, buckle, crush, or longitudinally bend.
(5) Be resistant to pressures, fatigue, and strain for the application.
(6) Be installed according to American Society for Testing and Materials, Standard Practice for
Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity -Flow Applications,
ASTM D2321 (2005). The standard is incorporated by reference, is available through the Minitex
interlibrary loan system, and is not subject to frequent change.
(7) Be designed, installed, and protected to minimize the danger of freezing in the pipe.
(8) Not be closer than six inches from final grade. Pipes susceptible to freezing shall be insulated.
(9) Be setback from the water supply wells and water service pipes according to Minnesota Rules
Chapters 4715 and 4725.
14.4 The minimum slope for gravity supply pipes is one percent ('/ -inch per linear foot). There is no maximum
slope. Pipe restraints must be used for slopes greater than 20 percent or where fluid velocities in the pipe
exceed 15 feet per second. For pressure systems, a minimum slope of one percent for drawback or other
frost protection measures must be employed.
14.5 Access to each supply pipe must be provided for cleanout. The access point must be accessible from final
grade.
14.6 Gravity Distribution
(1) Serial distribution must be used to distribute effluent to individual trenches in a soil treatment and
dispersal system. If the necessary elevation differences between trenches for serial distribution
cannot be achieved by natural topography or by varying the excavation depths, parallel distribution
can be used. Serial distribution must not create a pressure head on trenches at lower elevations.
(2) If drop boxes are used for serial distribution, Subitems (A) to (F) apply.
50 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
(A) The drop box must be watertight and constructed of durable materials not subject to
corrosion or decay.
(B) The invert of the inlet supply pipe must be at least one inch higher than the invert of the
outlet supply pipe to the next drop box.
(C) The invert of the outlet supply pipe to the next drop box must be no greater than two inches
higher than the crown of the distribution pipe serving the trench in which the box is
located.
(D) When sewage tank effluent is delivered to the drop box by a pump, the pump discharge
must be directed against a wall or side of the box on which there is no outlet or directed
against a deflection wall, baffle, or other energy dissipater. The discharge rate into the drop
box must not result in surfacing of sewage from the drop box. The supply pipe must drain
after the pump shuts off.
(E) The drop box must be covered by a minimum of six inches of soil. If the top of the box is
deeper than six inches, access must be provided above, at, or within six inches of finished
grade.
(F) The drop box must be placed on firm and settled soil.
(3) If valve boxes are used, all requirements in Section 14.G (2) apply.
(4) Distribution boxes must meet the standards in items (A) to (F).
(A) The box must be watertight and constructed of durable materials not subject to corrosion or
decay.
(B) The distribution box must be covered by a minimum of six inches of soil. If the top of the
box is deeper than six inches, access must be provided above, at, or within six inches of the
finished grade.
(C) The inverts of all outlets must be set and maintained at the same elevation.
(D) The inlet invert must be either at least one inch above the outlet invert or sloped such that an
equivalent elevation above the outlet invert is obtained within the last eight feet of the inlet
pipe.
(E) Each trench line must be connected separately to the distribution box and must not be
subdivided. Distribution boxes must not be connected to one another if each box has
distribution pipes.
(F) When sewage tank effluent is delivered by pump, a baffle wall must be installed in the
distribution box or the pump discharge must be directed against a wall, baffle, side of the box
on which there is no outlet, or directed against a deflection wall, baffle, or other energy
dissipater. The baffle must be secured to the box and extend at least one inch above the
crown of the inlet pipe. The discharge rate into the drop box must not result in surfacing of
sewage from the drop box. Pressure must not build up in the box during pump discharge.
(5) Nonpressurized distribution pipes must meet the requirements of items (1) to (4) below and Section
IL-1 (11 and Section 14.3 (3) to Section 14.3 (5).
51 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
(1) Distribution pipes used for gravity distribution must be at least four inches in diameter.
(2) Distribution pipes used for gravity distribution must have at least one row of holes of no less
than one -half inch in diameter spaced no more than 40 inches apart.
(3) Distribution pipes for gravity distribution must be laid level or on a uniform slope oriented
away from the distribution device of no more than four inches per 100 feet.
(4) Distribution pipes for gravity distribution in seepage beds must be uniformly spaced no more
than five feet apart and not more than 30 inches from the side walls of the seepage bed.
14.7 Pressure Distribution
(1) Pressure distribution must pressurize the entire distribution system and must be used for:
(A) Mound systems.
(B) At -grade systems,
(C) All trenches and seepage beds in accordance with Mimesota Rules, Chapter 70805.
(D) All seepage beds with a width greater than 12 feet
(E) New construction or replacement systems receiving treatment Level A or Level B effluent, as
determined in Minnesota Rules, 7083.4030, Table III.
(F) All systems where the distribution network is installed above the original grade.
(U) All MSTS.
(2) Pressurized distribution pipes must conform to the requirements of Section 14.' ) ('t) and Section 14.3
u to Section 14.3 (51.
(3) Pressure distribution pipes and associated fittings must be properly joined together. The pipe and
connections must be able to withstand a pressure of at Least 40 pounds per square inch.
(4) The distribution network must be designed so there is less than a ten percent variance in flow for all
perforations.
(5) Perforations must be no smaller thatl/e -inch diameter and no larger than 1/4 -inch diameter. The
number of perforations, perforation spacing, and pipe size for pressure distribution must be in
accordance with Table IV below. The friction loss in any individual perforated lateral must not
exceed 20 percent of the average pressure head on the perforations.
52 Washington County Development Code
Effective September 23, 2009 Chapter Four f• Subsurface Sewage Treatment System Regulations
Table TV —Maximum Number of Pprforatinnc Por i ataral
(6) Perforation holes must be drilled straight into the pipe and not at an angle. Pressurized distribution
laterals must be installed level. Perforation holes must be free of burrs. Holes must be spaced no
more than three feet apart. A method to introduce air into the pipe after dosing must be provided.
The pipes must completely drain after the pump turns off.
(7) Pressure distribution laterals must be spaced no further than 36 inches apart in seepage beds and
mound absorption beds, and no further than 24 inches from the outside edge of the bed.
(8) Pressure distribution laterals must be connected to a header or manifold pipe that is of a diameter
such that the friction loss in the header or manifold will be no greater than five percent of the
average head at the perforations. The header of manifold pipe must be connected to the supply pipe
from the pump.
(9) Perforated laterals must not be installed closer than 12 inches from the edges of the absorption bed
and perforated laterals must terrninate no closer than 12 inches from the ends of the absorption bed.
(10) Pressure distribution cleanouts must be provided to check the system for proper operation and
cleaning of plugged perforations. Cleanouts must be accessible from final grade.
(11) Existing systems with gravity distribution which are retrofitted with an advanced treatment device
meeting treatment level A or B in Minnesota Rules 7083 4030, must monitor the system to
determine the presence of even distribution over the absorption area. If even distribution is not
occurring, pressure distribution must be employed.
53 Washington County Development Code
x
2.0 10 13
18 30
60
2.5 8 12
16 28
54
3.0 8 12
16 25
52
2.0 11
16 21 34
68
2.5 10
14 20 32
64
10 9
14 119 30
60
NO-
2.0 12 18
26 46
2.5
12 17
24 40
80
3.0 12 16
22 37
75
a
9
2.0 21 33
44 74
149
2.5
20 30
41
69
135
3.0
20 29
38
64
128
(6) Perforation holes must be drilled straight into the pipe and not at an angle. Pressurized distribution
laterals must be installed level. Perforation holes must be free of burrs. Holes must be spaced no
more than three feet apart. A method to introduce air into the pipe after dosing must be provided.
The pipes must completely drain after the pump turns off.
(7) Pressure distribution laterals must be spaced no further than 36 inches apart in seepage beds and
mound absorption beds, and no further than 24 inches from the outside edge of the bed.
(8) Pressure distribution laterals must be connected to a header or manifold pipe that is of a diameter
such that the friction loss in the header or manifold will be no greater than five percent of the
average head at the perforations. The header of manifold pipe must be connected to the supply pipe
from the pump.
(9) Perforated laterals must not be installed closer than 12 inches from the edges of the absorption bed
and perforated laterals must terrninate no closer than 12 inches from the ends of the absorption bed.
(10) Pressure distribution cleanouts must be provided to check the system for proper operation and
cleaning of plugged perforations. Cleanouts must be accessible from final grade.
(11) Existing systems with gravity distribution which are retrofitted with an advanced treatment device
meeting treatment level A or B in Minnesota Rules 7083 4030, must monitor the system to
determine the presence of even distribution over the absorption area. If even distribution is not
occurring, pressure distribution must be employed.
53 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
14.8 For MSTS, distribution of effluent into a soil treatment and dispersal area must comply with all parts of
Section 14.
14.9 MSTS must be designed by a registered professional engineer and approved by the Department or local unit
of government.
14.10 MSTS must employ pressure distribution.
14.11 The distribution system for MSTS must be designed to dose and rest zones in accordance with operational
requirements.
54 Washington County Development Code
Effective September 23, 2009 Chapter Four + Subsurface Sewage Treatment System Regulations
SECTION 15 DOSING OF EFFLUENT
15.1 When pumping or dosing is necessary, it must comply with this Section.
15.2 Pump tanks shall meet or exceed the requirements of Section 13 2, Sections 13.11 through Section 13.20.
All dosing chambers must be vented. Pump tanks shall have a maintenance hole with a minimum diameter
of 20 inches (least dimension) which allows access and removal of any plumbing or other device. These
maintenance holes shall meet or exceed the requirements of Section 13.12 and Section 13.13 of this
Chapter.
15.3 The pump, pump controls, and pump discharge line must be installed to allow access for servicing or
replacement without entering the pump tank.
15.4 The pump tank must either include:
(1) An alternating two -pump system; or
(2) Have a minimum total capacity of
(A) 500 gallons for design flows of 600 gallons per day or less; or
(B) 100 percent of the design flow for design flow values of greater than 600 gallons per day.
(3) MSTS and Other Establishments must include an alternating two -pump system and have a
minimum capacity of 50 percent of the design flow.
15.5 An SSTS with a pump must employ an alarm device to warn of failure.
15.6 The inlet of pumps must be elevated at least four inches from the bottom of the purnp tank or protected in
some other manner to prevent the pump from drawing excessive settled solids.
15.7 Electrical installations must comply with applicable laws and ordinances including the most current codes,
rules -, and regulations of public authorities having jurisdiction and with Minnesota Rule. Chanter
13 15.0200, which incorporates the National Electrical Code.
15.8 If a pump is used to lift effluent into a gravity distribution system, the following apply:
(1) The pump must discharge at least 10 gallons per minute but no more than 45 gallons per minute.
(2) The pump must be constructed and fitted with sound, durable, and corrosion- resistant materials.
(3) The pump must have sufficient dynamic head for both the elevation difference and friction loss.
15.9 Pumps used for pressure distribution must meet the following requirements:
(1) Pumps must be constructed and fitted with sound, durable, and corrosion- resistant materials.
(2) The pump discharge capacity must be based on the perforation discharges for a minimum average
head of:
(A) 1.0 foot for `/a -inch and 3/16 -inch perforations for dwellings;
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
(B) 2.0 feet for 1/8 -inch perforations for dwellings
(C) 2.0 feet for %a -inch and 3/16 -inch perforations for MSTS and other establishments; and,
(D) 5.0 feet for 1/8 -inch perforations for MSTS and other establishments.
(3) Perforation discharge is determined by the following formula:
Q = 19.65 cd'h"
Where: Q = Discharge in Gallons Per Minute (GPM)
c = 0.6- = coefficient of discharge
d = perforation diameter in inches
h = head in feet
15.10 The pump discharge head must beat least five feet greater than the head required to overcome pipe friction
losses and the elevation difference between the pump and the distribution device.
15.11 The quantity of effluent delivered for each pump cycle must be no greater than 25 percent of the design
flow and at least five times the volume of the distribution pipes plus one volume of the supply pipe.
56 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
SECTION 16 TREATMENT AND DISPERSAL
16.1 Treatment and dispersal of all sewage for new construction or replacement SSTS must in compliance with
this Section and Section 17 to Section 21.
16.2 All new construction or replacement SSTS must be designed to meet or exceed the following provisions:
(1) All treatment and dispersal methods must be designed to conform to all applicable federal, state,
and local regulations.
(2) Treatment and dispersal processes must prevent sewage or sewage effluent contact with humans,
insects, or vermin.
(3) Treatment and dispersal of sewage or sewage effluent must be in a safe manner that adequately
protects from physical injury or harm.
(4) An unsaturated zone in the soil must be maintained between the bottom of the soil treatment and
dispersal system and the periodically saturated soil or bedrock during loading of effluent.
(5) Soil treatment and dispersal systems must not be designed in floodways. Soil treatment and
dispersal systems installed in flood fringes must meet the requirements of Section 18.3. All soil
treatment systems located in areas subject to excessive run -on must have a diversion constructed
upslope from the system.
(6) SSTS components must be setback in accordance with Table V.
(7) No component of an SSTS is allowed to be located under or within the structure or other
impermeable surface.
(8) Flow measurement must be employed for all single family dwellings and other establishments with
a pump tank, all single family dwellings with a Type III, N, V systems, and all multi- family
dwellings.
57 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
Table V — Minimum Setback Distances (Feet
l eatctre . ':"
,Sewa ag7mt, ..
Soil Treatment and,
` `� s ersal Area
Water supply wells less than 50 feet deep and not
encountering at least 10 feet of impervious material
50
100
Any other water supply well or buried suction pipe
50
50
Buried pipe distributing water under pressure
10
10
Occupied buildings and buildings with basements or
crawls aces
10
20
Non - occupied structures
5
10
Pro erty lines
10
10
Above ground and in —round swimming pools
10
10
Tie•rna3 High iln #erIaxl %o3.,'
Natural Environment Lakes and Streams
150
150
Recreational Development Lakes and Streams
75
75
General Development Lakes and Streams
75
75
All unclassified waters
75
75
St. Croix River -Rural Districts
150
150
St. Croix River -Urban Districts
100
100
b,fixiiES a a
St. Croix River Blufflines
40
40
Shoreland Blufflines
20
20
16.3 The following items are required for specific designs as determined in Section 17 to Section 21.
(1) Employ components registered under Minnesota Rules 7083.4070 and 7083.4080 that are installed,
used and operated according to the conditions placed on the registration.
(2) Employee structural components and joint sealants that meet or exceed the system's expected
design life.
(3) For acceptable treatment of septic tank effluent by soil, the soil treatment and dispersal systems
must meet the following requirements:
(A) A minimum three -foot vertical soil treatment and dispersal zone shall be designed below
the distribution media that meets the following criteria:
(i) The zone must be above the periodically saturated soil and bedrock. The zone
must be continuous and not be interrupted by seasonal zones of saturation.
(ii) Any soil layers with a texture group of 1 in Table IX in Minnesota Rules, Chapter
7080.2150' must not be credited as part of the necessary three -foot zone.
(iii) The entire treatment zone depth must be within seven feet from final grade.
(B) The distribution system or media must not place a hydraulic head greater than 30 inches
above the bottom of the absorption area.
(4) The system's absorption area must be in original soil.
58 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
(5) The system's absorption area must be sized according to the Table IX- Loading Rate for
Determining Bottom Absorption Area for Trenches and Seepage Beds for Effluent Treatment Level
C and Absorption Ratios for Determining Mound Absorption Areas Using Detailed Soil
Descriptions as found in Minnesota Rules, Chanter 7080 2150, or by using Table VI if not using
detailed soil descriptions. Soils with a loading rate less than 0.45 gallons per day per square foot
cannot be used in a Type I or Type II system for new construction.
Table VI
Loading Rates for Determining Bottom Absorption Area for Trenches and Seepage Beds for Effluent
Treatment Level C and sorption Ratios for Determining Mound Absorption Areas using Percolation Tests
* See Section 18.2 for a system with this type of soil (Type II, Rapidly Permeable Soils
Systems)
** Soil with too high a percentage of clay for installation of a Type I, or Type 11 system.
Systems in soils with this Percolation Rate must be a Type 111, Type IV or Type V system.
(6) If drainfield rock medium is employed, a durable, nonwoven geotextile fabric must be used to
cover the distribution rock medium. The fabric must be of sufficient strength to undergo
installation without rupture. The fabric must permit passage of water without passage of overlying
soil material into the rock medium.
(7) All excavation into the absorption area, or surface preparation of the upper 12 inches of the
absorption area, must be in a manner to expose the original soil structure in an unsmeared and
uncompacted condition. Excavation is only allowed when the soil moisture content is at or less
than the plastic limit and is not frozen or freezing.
(8) Excavation equipment or other vehicles must not be driven on the excavated or prepared absorption
area. Foot traffic on these areas must be minimized and not cause compaction. The exposed areas
must be immediately covered with the media or designed coverage materials. If the areas are
exposed to direct rainfall, they must be allowed to dry and must be re- prepared according to Section
Iti.3 (7).
(9) A minimum of six inches of topsoil borrow shall be placed over the system.
(10) A close - growing, vigorous vegetative cover must be established over the soil treatment and
dispersal system and other vegetatively disturbed areas. The sodding, seeding, or vegetation
establishment shall begin immediately after the placement of the topsoil borrow. The soil treatment
and dispersal system must be protected from erosion and excessive frost until a vegetative cover is
established. The vegetative cover established must not interfere with the hydraulic performance of
59 Washington County Development Code
°Rop
ercola€�o mate
nuteser�)2afe
'N
on
���tio.�
�,�
0.1 --5*
1.20
1
0.1 — 5 (Soil Texture
0.6
2
Grow 3
6— 15
0.78
1.3
16 -30
2
31 —45
_0.6
0.5
2.4
46-60
0.45
2.6
>60 **
0.24
5.0
* See Section 18.2 for a system with this type of soil (Type II, Rapidly Permeable Soils
Systems)
** Soil with too high a percentage of clay for installation of a Type I, or Type 11 system.
Systems in soils with this Percolation Rate must be a Type 111, Type IV or Type V system.
(6) If drainfield rock medium is employed, a durable, nonwoven geotextile fabric must be used to
cover the distribution rock medium. The fabric must be of sufficient strength to undergo
installation without rupture. The fabric must permit passage of water without passage of overlying
soil material into the rock medium.
(7) All excavation into the absorption area, or surface preparation of the upper 12 inches of the
absorption area, must be in a manner to expose the original soil structure in an unsmeared and
uncompacted condition. Excavation is only allowed when the soil moisture content is at or less
than the plastic limit and is not frozen or freezing.
(8) Excavation equipment or other vehicles must not be driven on the excavated or prepared absorption
area. Foot traffic on these areas must be minimized and not cause compaction. The exposed areas
must be immediately covered with the media or designed coverage materials. If the areas are
exposed to direct rainfall, they must be allowed to dry and must be re- prepared according to Section
Iti.3 (7).
(9) A minimum of six inches of topsoil borrow shall be placed over the system.
(10) A close - growing, vigorous vegetative cover must be established over the soil treatment and
dispersal system and other vegetatively disturbed areas. The sodding, seeding, or vegetation
establishment shall begin immediately after the placement of the topsoil borrow. The soil treatment
and dispersal system must be protected from erosion and excessive frost until a vegetative cover is
established. The vegetative cover established must not interfere with the hydraulic performance of
59 Washington County Development Code
Effective September 23, 2009 Chapter Four 4- Subsurface Sewage Treatment System Regulations
the system and shall provide adequate frost and erosion protection. Trees, shrubs, deep - rooted
plants, or hydrophytic plants must not be planted on the system.
16.4 At a minimum, systems designed under this Chapter with a design flow of greater than 2,500 gallons per
day, which impact water quality of an aquifer, as defined in Minnesota Rules, Chapter 4725.0100, subpart
21, must employ best management practices for nitrogen reduction developed by the Commissioner to
mitigate water quality impacts to groundwater.
16.5 Final treatment and dispersal for MSTS shall meet the following requirements:
(1) Final treatment and dispersal must be according to applicable design requirements of this Chapter,
except as modified in this Section: Code of Federal Regulations, Title 40. Parts 144 and 146,
prescribe additional design regulations applicable to certain systems. At a minimum, flow amounts
to be used for the purpose of this Section must be derived from Table II in Section 12 of this
Chapter.
(2) MSTS must meet all setbacks in Table V.
(3) The site proposed to support the soil treatment and dispersal system must:
(A) Have the upper 18 inches of the absorption area:
(i) Be original soil.
(ii) Have a soil loading rate of greater than zero as listed in Table IX in Minnesota
Rules. Chapter 7080.2150' or Table VI, in Section 16.3.
(iii) Be above the periodically saturated soil or bedrock.
(B) Meet the area size requirements in Section 16.5 (5) and Setbacks in Table V.
(C) Not be a wetland or floodway.
(D) Not be in an area in which surface runoff from precipitation will concentrate (concave
hillslope).
(E) Allow the system to be placed on contour.
(4) Inspection pipes must be located to adequately assess the hydraulic performance of the entire soil
dispersal system.
(5) Effluent loading rates to the soil shall be no greater than loading rates prescribed in:
(A) Table IX in Minnesota Rules. Chapter 7080.2150', or'Iable VI in Section 16.3, if the
absorption area receives treatment level C effluent as defined in Minnesota Rules
7083.4030.
(B) Table XII in Minnesota Rules. Chapter 7080.2350', or Table X in Section 20.5, if the
absorption area receives treatment level A or B effluent in part Minnesota Rules,
7083.4030.
(C) Section 21.
60 Washington County Development Code
Effective September 23, 2009 Chapter Four %• Subsurface Sewage Treatment System Regulations
(6) If the absorption area receives effluent as described in Section 16.5 (5)(A), the absorption area shall
be increased by 50 percent of the amount derived in Section] 6.5 (5)(A), and zoned for dosing and
resting.
(7) The system geometry and lawn area sizing shall be sized to prevent groundwater mounding from
violating the unsaturated zone beneath the soil system according to Section 16.5 (8) for proper
hydraulic functioning, and for concentration reduction of nitrogen and phosphorus, if applicable.
(8) Additional set -aside land area of 100 percent of the size determined in Section 16.5 (7) is required
for systems whose absorption area receives effluent meeting treatment level A or B in part
Minnesota Rules, 7083 4030 or designed in accordance with Section 21. Additional land area of 50
percent of the size determined in Section 16.5 (7) is required for systems whose absorption area
receives treatment level C in part Minnesota Rules. 7083 4030. The reserve land area must be
identified and protected for future use if necessary. Replacement MSTS proposed on sites that
cannot meet this requirement are allowed to be exempted by the Department or local unit of
government.
(9) For treatment of effluent by soil to meet the performance criteria in Section 4.9 (3) of this Chapter,
the soil treatment and dispersal systems must meet the requirements below:
(A) For soil treatment and dispersal systems that receive treatment level C effluent as described
in Minnesota Rules, 7083 4030, the soil treatment zone requirements must meet or exceed
the requirements of Section 16.3 (3). The required three -foot vertical separation must be
maintained during operation after accounting for groundwater mounding.
(B) For soil treatment and dispersal systems that receive treatment level A or B effluent as
described in Minnesota 7083 4030, the soil treatment requirements must meet or
exceed the following requirements:
(i) A minimum vertical depth of the soil treatment and dispersal zone below the
distribution media shall be determined according to Table IX in Section 20, with a
minimum vertical separation of two feet. This zone shall meet the following
criteria:
a. The zone must be above the periodically saturated soil and bedrock. The
zone must be continuous and not be interrupted by seasonal zones of
saturation.
b. Any soil layers with a texture group of 1 in Table IX in Minnesota Rules
Chapter 7080.2150' must not be credited as part of the necessary treatment
zone.
C. The entire treatment zone depth must be within seven feet from final grade.
(ii) The distribution system or media must not place a hydraulic head greater than 30
inches above the bottom of the absorption area.
(iii) The system's absorption area must be original soil.
(iv) The systems absorption area must be sized according to Sect on I G.5 (5).
61 Washington County Development Code
Effective September 23, 2009 Chapter Four + Subsurface Sewage Treatment System Regulations
(C) The minimum vertical separation can be determined by the method described in Section 21
to meet provisions of Section 4.9 (3).
(D) An observation well to measure the height of the periodically saturated soil beneath the
operating system must be installed and monitored according to the operating permit.
(10) MSTS systems must employ nitrogen mitigation methods to achieve compliance with Section 4.9
(4), and must be monitored in accordance with Section 11.4 of this Chapter.
(11) Phosphorus mitigation methods must be employed to achieve compliance with Section 4.9J5), if
natural processes are found inadequate.
(12) All information required in this Section shall be submitted for review and approval by the
Department or local unit of government prior to system construction, including all applicable
information delineated on a map.
16.6 MSTS construction must be according to applicable construction requirements of this Chapter.
16.7 The design standards for new construction or replacement MSTS are provided to meet many of the public
health and environmental outcomes in Section 4. In some cases, specific design methods must be employed in
addition to the standards provided in this Chapter.
16.8 MSTS must not receive storm water or other sources of clean water.
16.9 All structural components of the system and sealants must be designed to operate throughout the system's
design life.
16.10 A flow measure device must be employed on all MSTS.
16.11 The system must be designed with sufficient access and ports to monitor the system as applicable.
16.12 MSTS must employ components registered under parts 7083.4000 to 7083.4110 or have sufficient regulatory
oversight in the operating permit.
16.13 The MSTS designer must observe critical periods of the system construction. The designer shall prepare a
report of observed construction activities and submit the report to the Department or local unit of
government prior to the final inspection.
62 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
SECTION 17 TYPE I SYSTEMS
17.1 Systems designed according to this Section are considered Type I Systems. Systems in soils with a loading
rate less than 0.45 gallons per day per square foot cannot be used in a Type I system for new construction.
17.2 Trenches and Seepage Beds
(1) To qualify as a trench or seepage bed system, the system must meet or exceed the following
requirements:
(A) Employ flow values in Section 12.
(B) Meet or exceed applicable technical requirements of Section 13, Section 1.4, and Section
15.
(C) Meet or exceed the requirements of Sections 16.2 and 16.3.
(D) Meet the requirements of Section 17.2 ( to Section 17 ? (151.
(2) Seepage bed placement must be limited to areas having natural slopes of less than six (6) percent
Absorption areas for seepage beds must not be placed in soils with a texture group of 8 on Table
IX in Minnesota Rules Chapter 7080.2150'. Seepage beds must not be located in floodplains.
(3) The trench bottom absorption area is calculated by dividing the design flow by the appropriate soil
loading rate in Table IX in Minnesota Rules Chapter 7080.2150' or Table VI.
(4) If gravity distribution is used in seepage beds, the seepage bed absorption area is calculated by
dividing the design flow by the soil loading rate and then multiplying that value by 1.5.
(5) If pressure distribution is used in seepage beds, the seepage bed absorption area is determined by
dividing the design flow by the soil loading rate in Table IX in Minnesota Rules Chapter
7080.2150' or Table VI.
(6) The minimum sidewall absorption is six (6) inches. The bottom absorption area is allowed to be
reduced, for gravity distribution trenches only, by the following:
Sidewall
Absorption-
Sizing
Inches
Equivalent
8 -11
7%
12-17
20%
18 -23
34%
24
40%
(7) Trenches must be no more than 36 inches wide. Any excavation wider than 36 inches shall be
considered a seepage bed.
(8) A seepage bed must not be wider than 12 feet if gravity distribution is used.
(9) A seepage bed must not be wider than 25 feet if pressure distribution is used.
(10) Natural, undisturbed soil must exist between multiple trenches and seepage beds.
63 Washington County Development Code
Effective September 23, 2009 Chapter Four + Subsurface Sewage Treatment System Regulations
(11) Multiple seepage beds must be spaced at one -half the bed width_ Multiple units must be designed
based on contour loading rates as described in Section 2.2 (22) and Section 17.3 (9).
(12) A vertical inspection pipe at least four inches in diameter must be installed and secured in the
distribution medium of every trench and seepage bed. The inspection pipe must be located at an
end opposite from where the sewage tank effluent enters the medium. The inspection pipe must
have three - eighths inch or larger perforations spaced vertically no more than six inches apart. At
least two perforations must be located in the distribution medium. Perforations must not be located
above the geotextile cover or wrap. The inspection pipe must extend to the bottom of the
distribution medium, be secured, and be capped flush with or above finished grade.
(13) The top and bottom of the distribution medium must be level along the contour. Sidewalls must be
as vertical as practical and not intentionally sloped.
(14) The minimum depth of soil cover, including topsoil borrow, over the distribution medium is 12
inches.
(15) Trenches or seepage beds must be backfilled and crowned above finished grade to allow for
settling. The top six inches of the backfill must have the same texture as the adjacent soil.
17.3 Mounds
(1) To qualify as a mound system, the system must meet or exceed the following requirements:
(A) Employ flow values in Section 12.
(B) Meet or exceed applicable technical requirements of Section 13, Section 14, and Section
15.
(C) Meet or exceed the requirements of Sections 16.2, and 16.3.
(D) Meet the requirements of Section 17.3 (2) to Section 17.3 (30A.
Location of Mounds
(2) The upper 18 inches of the original soil mound absorption area must have a minimum loading rate
of 0.45 gallons per day per square foot and a mound absorption ratio greater than zero, but no more
than 2.6 in Table IX in Minnesota Rules, Chapter 7080.2150' or Table VI. The upper 18 inches of
the absorption area must also be above the periodically saturated soil or bedrock.
(3) For previously developed sites, the upper 12 inches of the original soil mound absorption area must
have a mound absorption ratio of greater than zero in Table IX in Minnesota Rules, Chapter
7080.2150' or Table VI. The upper 12 inches of the absorption area must also be above the
periodically saturated soil or bedrock.
(4) Setbacks must be according to Table V. Setbacks must be measured from the original soil
absorption area.
(5) On slopes of one percent or greater and where the original soil mound absorption ratio is 2.6 or
greater in Table IX in Minnesota Rules, Chapter 7080.2150' or Table VI, mounds must not be
64 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
located where the ground surface contour lines that lie directly below the long axis of the
distribution media bed represent a Swale or draw, unless the contour lines have a radius of curvature
greater than 100 feet. In no case shall mounds be placed on slopes greater than 12 percent.
(6) Mounds must never be located in swales or draws where the radius of curvature of the contour lines
is less than 50 feet.
Mound Design and Construction
(7) The mound distribution media bed area consists of bottom area only and must be calculated by
dividing the design flow by 1.0 gallons per square foot per day.
(8) The mound distribution media bed area must be as long and narrow as practical. Mound
distribution media beds must be no wider than ten feet.
(9) Mound distribution bed length and width must be determined by the contour loading rate, which is
the relationship between the vertical and horizontal water movement based on the following soil
conditions:
(A) The permeability difference between the original soil mound absorption area and slower
permeability horizons below the original soil mound absorption area.
(B) The depth between the original soil mound absorption area and the change in permeability
described in Subitem (A).
(C) The land slope.
(10) Clean sand must be used to elevate the mound distribution media bed and must consist of sound,
durable material that conforms to the following requirements:
Clean sand must also contain less than three percent deleterious substances and be free of organic
impurities.
(11) The original soil mound absorption area is determined by multiplying the original soil mound
absorption length by the original soil mound absorption width. The original soil absorption width is
calculated by multiplying the mound distribution media bed width by the mound absorption ratio.
The mound absorption ratio of the upper 18 inches of soil for new construction, or 12 inches of soil
for previously developed sites, in the proposed original soil mound absorption area shall be
determined according to Table IX in Mimiesota Rules Chapter 7080 2150 or Table VI.
(12) The required original soil absorption width for mounds constructed on slopes from zero to one
percent must be centered under the mound distribution media bed width. The required original
mound soil absorption width constructed on slopes greater than one percent must be measured
65 Washington County Development Code
Effective September 23, 2009 Chapter Four C. Subsurface Sewage Treatment System Regulations
downslope from the upslope edge of the mound distribution media bed width and measured in the
direction of the original land slope and perpendicular to the original contours.
(13) The side slopes on the mound must no be steeper than three horizontal units to one vertical unit and
shall extend beyond the required absorption area, if necessary.
(14) Distribution of effluent over the mound distribution media bed must be by level perforated pipe
under pressure according to Section 14 and Section 15.
(15) The supply pipe from the pump to the original soil absorption area must be installed before surface
preparation of the original mound soil absorption area. The trench excavated for the supply pipe
must be carefully backfilled and compacted to prevent seepage of effluent.
(16) Vegetation in excess of two inches in length and dead organic debris including leaf mats must be
removed from the original soil mound absorption area. Trees must be cut nearly flush with the
ground and stumps must not be removed.
(17) The original soil mound absorption area must be roughened by backhoe teeth, moldboard, or chisel
plow. The soil must be roughened to a depth of eight inches. Discing is allowed if the upper eight
inches of soil has a texture of sandy loam or coarser. If plowed, furrows must be thrown uphill and
there must not be a dead furrow in the original soil mound absorption area. A rubber tired tractor is
allowed for plowing or discing. Rototilling or pulverizing the soil is not allowed. The original soil
must not be excavated or moved more than one foot from its original location during soil surface
preparation.
(18) All surface preparation must take place when the upper 12 inches of soil has a moisture content of
less than the plastic limit and soil conditions allow field testing of soil properties and these
properties are maintained throughout the installation.
(19) Prior to placement of six inches of clean sand, vehicles must not be driven on the original soil
mound absorption area before or after the surface preparation is completed. The clean sand must
immediately be placed on the prepared surface.
(20) If rainfall occurs on the prepared surface, the site must be allowed to dry below the plastic limit and
roughened as described in Section 17.3 (17).
(21) The clean sand must be placed by using a construction technique that minimizes compaction. If the
clean sand is driven on for construction, a crawler or track -type tractor must be used. At least six
inches of sand must be kept beneath equipment to minimize compaction of the prepared surface.
(22) A minimum of 12 inches of clean sand must be placed in contact with the bottom area of the mound
distribution media bed and must be uniformly tapered to cover the entire original soil absorption
area. Other sandy materials are allowed to be used outside of this area to complete construction of
the mound.
(23) The top of the clean sand layer upon which the mound distribution media bed is placed must be
level in all directions.
(24) A vertical inspection pipe at least four inches in diameter must be installed and secured at the
distribution medium and sand interface. The inspection pipe must have three - eighths inch or larger
perforations spaced vertically no more than six inches apart. At least two perforations must be
located in the distribution medium. Perforations must not be located above the permeable synthetic
66 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
fabric, if used. The inspection pipe must extend to the bottom of the distribution medium, be
secured, and be capped, flush with or above finished grade.
(25) On slopes of one percent or greater, the upslope edge of the mound absorption bed must be placed
on the contour.
(26) The sidewalls of the mound absorption bed must be as vertical as practical and not intentionally
sloped.
(27) A minimum of six inches of sand, sandy loam or loam material must be placed on the top of the
mound absorption bed and sloped upwards towards the center of the mound a minimum of ten
horizontal units to one vertical unit.
(28) Construction vehicles must not be allowed on the distribution media until backfill is placed as
described in Section 17.3 (27).
(29) A minimum of six inches of topsoil borrow must be placed over the entire mound.
(30) A vegetative cover must be established over the entire area of the mound. The mound shall be
protected until a vegetative cover is established by use of erosion control. The established
vegetative cover shall not interfere with the hydraulic performance of the system and shall provide
adequate frost and erosion protection.
17.4 At -Grade Systems
(1) To qualify as an at -grade system, the system must meet or exceed the following requirements:
(A) Employ flow values in Section 12.
(B) Meet or exceed applicable technical requirements of Section 13, Section 14, and Section
15.
(C) Meet or exceed the requirements of Sections 16.2 and 16.3.
(D) Meet the requirements of Section 17.4 (2) to Section 17.4 (14).
(2) The upper 12 inches of the absorption area must have a loading rate of 0.45 gallons per day per
square foot or greater as shown in Table IX in Minnesota Rriles Chapter 7080 2150' or Table VI.
(3) At -grade systems must not be installed in areas with slopes greater than 12 percent.
(4) Setbacks must be according to Table V. Setbacks must be measured from the original soil
absorption area.
Design and Construction of At -Grade Systems
(5) The at -grade absorption width must be as long and narrow as practical. The at -grade absorption
width must not exceed a width of 15 feet. The at -grade absorption widths must be determined by
the contour loading rate, which is the relationship between the vertical and horizontal water
movement water movement based on the following soil conditions:
67 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
(A) The permeability difference between the original soil mound absorption area and slower
permeability horizons below the original soil mound absorption area.
(B) The depth between the original soil mound absorption area and the change in permeability
described in Section 17.4 (5)(A).
(C) The land slope.
(6) The minimum at -grade absorption bed width shall be calculated by dividing the contour loading
rate by the soil loading rate of the upper 12 inches of soil.
(7) The minimum at -grade absorption length must be calculated by dividing the design flow by the soil
loading rate found in Table IX in Minnesota Rules, Chanter 7080.2150' or Table VI for the upper
12 inches of soil and then dividing that value by the absorption bed width.
(8) The at -grade bed absorption width for slopes of one percent or greater does not include any width
of the media necessary to support the upslope side of the pipe.
68 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
Table VII
At -Grade Contour Londina Rates
*See Section 18.2 for a system with this type of soil (Type II, Rapidly Permeable Soils Systems)
(9) At -grade systems must employ pressurized distribution by meeting or exceeding the applicable
requirements of Section 14 and Section 15. At -grade systems located on slopes of one percent or
greater require only one distribution pipe located on the upslope edge of the distribution media,
with the absorption bed width being measured from the distribution pipe to the downslope edge of
the media. Multiple distribution pipes are allowed to be used to provide even distribution, if
necessary, based on site conditions.
g! 3
».w
O�yOISP,
ti'zsEu %e*'r
xleT .CI18.72C1:,CI1S#ffC8334,d
#E y - "..
No textural change
6
0.00
Coarse
Sand
Saturated soil <3'
S
Bedrock <4'
No textural thane
g
Sand
Layers of other textures
7
0.1 to 5.0
1.60
Loamy
Banding
4
Sand Fine
Saturated soil <3'
5
Sand
Bedrock <4'
5
Strong to moderate structure
7
No textural change
Weak structure
6 to 15
1.00
Sandy
Loam
Layers of other textures
6
Platy or massive structure
Saturated soil <3'
5
Bedrock <4'
Strong to moderate structure
Loam
No textural change
6
Sill Loan,
Weak structure
16 to 60
10.6 -0.78
Clay Loam
La ers of other textures
5
Platy or massive structure
Sandy Clay
Silty Clay
Saturated soil <3'
4
Bedrock <4'
Strong to moderate stricture
3
No textural change
Weak structure
Clay
61 1112020
Z
0.0 -0.3
Sandy Clay
Layers of other textures
Platy or massive structure
Silty Clay
Saturated soil <3'
2
Bedrock<4'
*See Section 18.2 for a system with this type of soil (Type II, Rapidly Permeable Soils Systems)
(9) At -grade systems must employ pressurized distribution by meeting or exceeding the applicable
requirements of Section 14 and Section 15. At -grade systems located on slopes of one percent or
greater require only one distribution pipe located on the upslope edge of the distribution media,
with the absorption bed width being measured from the distribution pipe to the downslope edge of
the media. Multiple distribution pipes are allowed to be used to provide even distribution, if
necessary, based on site conditions.
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
(10) The upslope edge of an at -grade absorption bed must be installed along the natural contour.
(11) At -grade materials must be placed using construction techniques that minimize compaction.
(12) Six inches of loamy or sandy cover material must be installed over the distribution media. Cover
must extend at least five feet from the ends of the rock bed and be sloped to divert surface water.
Side slopes must not be steeper than four horizontal units to one vertical unit. Six inches of topsoil
borrow must be placed on the cover material.
(13) One vertical inspection pipe of at least four inches in diameter must be installed along the
downslope portion of the absorption bed. The inspection pipe must have three - eights inch or larger
perforations spaced vertically no more than six inches apart. Perforations must not exist above the
distribution medium. The inspection pipe must extend to the absorption bed and soil interface, be
secured, and be capped, flush with or above finished grade.
(14) A vegetative cover must be established over the entire area of the at- grade. The at -grade shall be
protected until a vegetative cover is established by use of erosion control. The established
vegetative cover shall not interfere with the hydraulic performance of the system and shall provide
adequate frost and erosion protection.
70 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
SECTION 18 TYPE II SYSTEMS
18.1 Systems designed according to this Section are considered Type II systems. Systems in soils with a loading
rate less than 0.45 gallons per day per square foot cannot be used in a Type 11 system for new construction.
18.2 Rapidly Permeable Soils
(1) A system must be designed under this part if the soil in the proposed absorption area, or within
three vertical feet of the absorption area, has a soil texture groups of 1 through 3 in Table IX in
Minnesota Rules Chapter 7080.2150' or a percolation rate of 0.1 to 5.0 minutes per inch in Table
VI. The system must meet or exceed the following requirements:
(A) Employ flow values in Section 12.
(B) Meet or exceed applicable technical requirements of Section 13, Section 14, and Section
15, except as modified in this part.
(C) Meet or exceed the requirements of Sections 17.2 to 17.4.
(D) Meet or exceed requirements of Section 16.2 and 16.3, except as modified in this Section.
(E) Meet the requirements of Section 18.2 (2) to Section 18.2 (3)
(2) The distribution media must not be in contact with soils with a texture group of 1 in Table IX in
Minnesota Rules Chapter 7080.2 1 Lo' or a percolation rate of less than 0.1 minutes per inch in
Table VI.
(3) If the distribution media is in contact with soil with soil texture groups 2 or 3 in Table IX in
Minnesota. Rules, Chapter 7080.2150' or a percolation rate of 0.1 to 5.0 minutes per inch in Table
VI, the distribution of effluent must comply with Minnesota Rules Chapter 70806.
18.3 Floodplain Areas
(1) SSTS must be designed under this part if the system is proposed to be located in a floodplain. A
system located in a floodplain must meet or exceed the following requirements:
(A) Employ flow values in Section 12.
(B) Meet or exceed applicable technical requirements of Section 1.3, Section 14, and Section
15 except as modified in this part.
(C) 'Meet or exceed the requirements of Sections 17.2 to 17.4.
(D) Meet or exceed requirements of Section 16.2 and 16.3, except as modified in this part.
(E) Meet the requirements of Section 18.3 (2) to Section 18.3 { 111.
(2) The allowed use of systems in floodplain; must be according to state and local floodplain
requirements.
Effective September 23, 2009 Chapter Four -3 Subsurface Sewage Treatment System Regulations
(3) An SSTS must not be located in a floodway and, whenever possible, placement within any part of
the floodplain should be avoided. If no alternative exists, a system is allowed to be placed within
the flood fringe if the requirements of Section 18.3 (4) to Section 18.3 (11) are met.
(4) There must be no inspection pipe or other installed opening from the distribution media to the soil
surface.
(5) An SSTS must be located on the highest feasible area of the lot and must have the location
preference over all other improvements, except the water supply well. If the ten -year flood data are
available, the bottom of the distribution media must be at least as high as the elevation of the ten -
year flood.
(6) If a pump is used to distribute effluent to the soil treatment and dispersal system, provisions shall be
made to prevent the pump from operating when inundated with floodwaters.
(7) When it is necessary to raise the elevation of the soil treatment system to meet the vertical
separation distance requirements, a mound system as specified in Section 17.3 is allowed to be used
with the following additional requirements:
(A) The elevation of the bottom of the mound bed absorption area must be at least on -half foot
above the ten -year flood elevation, if ten -year flood data are available.
(B) In no case shall the sand fill for the mound exceed 48 inches below the mound bed
absorption area.
(C) Inspection pipes must not be installed unless the top of the mound is above the 100 -year
flood elevation.
(D) The placement of clean sand and other fill must be done according to any community
adopted floodplain management ordinance.
(8) When the top of a sewage tank is inundated, the dwelling must cease discharging sewage into it.
(9) Backflow prevention of liquid into the building when the system is inundated must be provided. If
a holding tank is used, the system must be designed to permit rapid diversion of sewage into the
holding tank when the system is inundated.
(10) If a holding tank is used to serve a dwelling, the holding tank's capacity must equal 100 gallons
times the number of bedrooms times the number of days between the ten -year stage on the rising
limb of the 100 -year flood hydrograph and the ten -year stage on the falling limb of the hydrograph,
of 1,000 gallons, whichever is greater. The holding tank must be accessible for removal of tank
contents under flooded conditions.
(11) Whenever the water level has risen above the top of a sewage tank, the tank must be pumped to
remove all solids and liquids after the flood has receded and before use of the system is resumed.
18.4 Privies
(1) Privies shall only be considered when there is no water supplied to the dwelling.
(2) Pit privies shall not be installed where the bottom of the pit is less than three feet above the
saturated soil or bedrock. A vault privy shall be used in areas not meeting the three foot separation.
72 Washington County Development Code
Effective September 23, 2009 Chapter Four d• Subsurface Sewage Treatment System Regulations
The vault of a vault privy shall be constructed in the same manner as a sewage tank in accordance
with Section 13.
(3) Privies shall be set back from surface waters, buildings, property lines, and water supply wells as
prescribed in Table V.
(4) Pits or vaults shall be of sufficient capacity for the dwelling they serve, but shall have at least 50
cubic feet of capacity. The sides of the pit shall be curbed to prevent cave -in. The privy shall be
constructed so as to be easily maintained and it shall be insect proof. The door and seat shall be
self - closing. All exterior openings, including vent openings, shall be screened.
(5) Privies shall be adequately vented.
(6) When the privy is filled to within one foot of the top of the pit, the solids shall be removed.
(7) Abandoned pits shall have the solids removed and be filled with clean earth and slightly mounded
to allow for settling. Removed solids shall be disposed of in accordance with Section 22.
18.5 Holding Tanks
(1) Holding tanks may be considered for installation on previously developed sites, as a temporary
method for periods of up to 12 months, during which time measures are taken to provide municipal
sewer service or the installation of an approved system as provided in this Chapter.
(2) Holding tanks may be considered on a permanent basis for non - residential, low water use
establishments with a sewage flow of 150 gallons per day or less, subject to approval by the
Department or local unit of government.
(3) Holding tanks must be used for floor drains for vehicle parking areas and existing facilities
potentially generating hazardous waste.
(4) To qualify as a holding tank, the system must:
(A) Meet or exceed applicable requirements of Section 13.
(B) Meet or exceed the applicable requirements of Section 16 2.
(C) Meet or exceed the requirements of Section 16.3 (2).
(D) Meet the requirements of Section 18.5 2 to Section 18.5 (101.
(5) All tanks used as holding tanks must be tested once placed at the final location for watertightness as
specified in Minnesota Rules Chanter 7080 2o10.
(6) A cleanout pipe of at least six inches in diameter must extend to the ground surface and be provided
with seals to prevent odor emissions and exclude insects and vermin. A maintenance hole of at
least 20 inches in least dimension must extend through the cover to a point within 12 inches, but no
closer than six inches, below finished grade. If the maintenance hole is covered with less than six
inches of soil, the cover must be secured according the Section 13_13.
73 Washington County Development Code
Effective September 23, 2009 Chapter Four d• Subsurface Sewage Treatment System Regulations
(7) For a dwelling, the minimum size is 1,000 gallons or 400 gallons times the number of bedrooms,
whichever is greater. For other establishments, the minimum capacity shall be at least five times
the design flow. Tank sizing for floodplain areas must be calculated according to Section 18.3 (' 10).
(8) Holding tanks must be located in an area readily accessible to the pump truck under all weather
conditions and where accidental spillage during pumping will not create a nuisance and must meet
the setback requirements of Table V.
(9) Holding tanks must have an alarm device to minimize the chance of accidental sewage overflow
unless regularly scheduled pumping is used. An alarm device shall identify when the holding tank
is at 75 percent capacity.
(10) A contract for disposal and treatment of the septage shall be maintained by the owner with a
licensed Maintainer.
74 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
SECTION 19 TYPE III SYSTEMS
19.1 A system designed according to this part is considered a Type III system. A system in soils with a loading
rate of less than 0.45 gallons per day per square foot may be installed on previously developed sites as a
Type III system. The system must:
(1) Employ design flow values in Section 12.
(2) Meet or exceed technical requirements in Section 14.7 (1).
(3) Meet or exceed the requirements of Section 16.2.
(4) Meet or exceed the requirements of Secfion 16.3 (1), Section 16.3 (21, Section 16.3 (3), Section
16.3 7 , Section 16.3 (8), and Section 16.3 ('9).
(5) For previously developed sites, if the site cannot accommodate a soil treatment and dispersal
system sized in accordance with Table IX in Minnesota Rules Chapter 7080 2150' or Table VI, a
smaller soil treatment and dispersal system is allowed to be constructed if it employs flow
restriction devices that do not allow loadings in excess of those in Table IX in Minnesota Rules,
Chanter 7080.2150' or Table VI.
19.2 Absorption areas sized smaller than a Type I system must employ flow restriction devices that to not allow
absorption area loadings in excess of those in Table IX in Minnesota Rules Chapter 7080.215 ' or Table
VI. This provision does not apply to the original soil, clean sand absorption area of a mound system.
19.3 Type III systems can be used on previously developed sites only when a Type I or Type II system cannot be
installed or is not the most suitable treatment.
19.4 Type III systems will not be allowed in areas where a new system or modifications to a new system are not
feasible if failure occurs.
19.5 Type III systems will be allowed for undeveloped lots only when two Type I or Type lI soil treatment and
dispersal areas have been identified on the lot, in addition to the area utilized by the Type III soil treatment
and dispersal area. The lot must be able to accommodate long -term sewage treatment in addition to the area
utilized by the Type III system.
19.6 Graywater Systems
(1) Graywater Systems shall be classified as a Type III system and must meet or exceed the following
requirements:
(A) Employ 60 percent of the flow values in Section 12.
(B) Meet or exceed applicable requirements of Section 13, Section 14, and Section 15, except
as modified in this part.
(C) Meet or exceed the requirements of Section 17.
(D) Meet or exceed the requirements of Section 16.2 and Section 163.
(E) Meet the requirements of Section 19.6U2 and Section 19.6 (3).
75 Washington County Development Code
Effective September 23, 2009 Chapter Four >A Subsurface Sewage Treatment System Regulations
(2) Toilet waste must not be discharged to a graywater system.
(3) The liquid capacity of a graywater septic tank serving a dwelling must be based on the number of
bedrooms existing and anticipated in the dwelling served and shall be at least as large as the
capacities given in Table VIII.
i ante viii — ivrimmum Leone r anK t-anacnv for
Two or less
1,000
500
Three
1,000
500
Four to Five
1,000
1,000
Six to Seven
1,000
1,000
Ei ht to Nine
1,500
1,000
Ten or More
Septic tank shall be sized as: (2,000 + ((# of bedrooms -
9) X 150)).
76 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
SECTION 20 TYPE IV SYSTEMS
20.1 A system designed according to this part is considered a Type N System- The system must:
(1) Employ design flow values in Section 12.
(2) Meet or exceed applicable technical requirements of Section 13, Section 14, and Section 15.
(3) Meet or exceed the requirements of Section 16 2.
(4) Meet or exceed the requirements of Section 16.3 (1) and Section 16.3 (2).
(5) Meet or exceed the requirements of Table TX and Table XII in Minnesota Rules Chanter
7080.2350' or Table X.
20.2 Type IV systems can be used on previously developed sites only when a Type I or Type II system cannot be
installed or is not the most suitable treatment.
20.3 Type IV systems will not be allowed in areas where a new system or modifications to a new system are not
feasible if failure occurs.
20.4 Type IV systems will be allowed for undeveloped lots only when two Type I or Type II soil treatment and
dispersal areas have been identified on the lot, in addition to the area utilized by the Type III soil treatment
and dispersal area. The lot must be able to accommodate long -term sewage treatment in addition to the area
utilized by the Type IV system.
Table IX
TREATMENT COMPONENT PERFORMANCE LEVELS AND METHOD OF DISTRIBUTION BY
MM "A um
12-17 I Treatment Level A, Pressure Distribution, Timed Dosing
18 -23
Treatment Level B, Pressure Treatment Level B, Distribution, Timed Dosing Pressure
Distribution
Treatment Level
24-36 B, Pressure Treatment Level B, Pressure
Distribution, Distribution
Timed Dosing
' The treatment component performance levels correspond with those established for treatment components
under the product testing requirements in Table III of Minnesota Rules, 7083 4030.
77 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
20.5 A Type IV system's absorption area must be sized according to Table XII- Loading Rates for Determining
Bottom Absorption Area for Trenches and Seepage Beds for Effluent Meeting Treatment Level A and B
and Absorption Ratios for Determining Mound Absorption Areas Using Detailed Soil Descriptions, as
found in Minnesota Rules, Chapter 7080.2350', or by using Table X if not using detailed soil descriptions.
Table X
LOADING RATES FOR DETERMINING BOTTOM ABSORPTION AREA FOR TRENCHES AND
SEEPAGE BEDS FOR EFFLUENT MEETING TREATMENT LEVELS A AND B AND ABSORPTION
RATIOS FOR DETERMINING MOUND ABSORPTION AREAS USING PERCOLATION TESTS.
0.1 -5* 1.60 1
0.1— 5 (Soil Texture 1.0 i 2
*See Section 18.2 for a system with this type of soil (Type 11, Rapidly Permeable Soils Systems)
78 Washington County Development Code
1
1.3
16 6 — — 3 30
0.77 8
, 2
31 -45
0.78
2.4
46-60
0.6
2.6
>60
0.3
5.0
*See Section 18.2 for a system with this type of soil (Type 11, Rapidly Permeable Soils Systems)
78 Washington County Development Code
Effective September 23, 2009 Chapter Four Z• Subsurface Sewage Treatment System Regulations
SECTION 21 TYPE V SYSTEMS
21.1 A system designed according to this part is considered a Type V system. The system must:
(1) Employ design flow values in Section 12.
(2) Meet or exceed the requirements of Section 16.2.
(3) Be designed with vertical separation that ensures adequate sewage dispersal and treatment. Design
factors to consider include, but are not limited to, effluent quality, loading rates, groundwater
mounding if loading rates are in excess of those in Table XTI in Minnesota Rules Chapter
7080.23504 or Table X, loading methods, and soil conditions. SSTS must not contaminate
underground waters or zones of periodic saturation with viable fecal organisms.
21.2 Type V systems can be used on previously developed sites only when a Type I or Type H system cannot be
installed or is not the most suitable treatment.
21.3 Type V systems will not be allowed in areas where a new system or modifications to a new system are not
feasible if failure occurs.
21.4 Type V systems will be allowed for undeveloped lots only when two Type I or Type II soil treatment and
dispersal areas have been identified on the lot, in addition to the area utilized by the Type III soil treatment
and dispersal area. The lot must be able to accommodate long -terra sewage treatment in addition to the area
utilized by the Type V system.
79 Washington County Development Code
Effective September 23, 2009 Chapter Four S• Subsurface Sewage Treatment System Regulations
SECTION 22 MAINTENANCE
22.1 All new and replacement SSTS must be operated in accordance with the management plan submitted,
reviewed and approved by the Department or local unit of government. At a minimum, management plans
must include the following:
(1) maintenance requirements, including frequency;
(2) operational requirements, including which tasks the owner can perform and which tasks a licensed
service provider or maintainer must perform;
(3) monitoring requirements;
(4) requirements that the owner notify the Department when the management plan requirements are not
met;
(5) disclosure of the location and condition of the additional soil treatment and dispersal area on the lot
or serving that residency; and
(6) other requirements determined by the Department.
22.2 SSTS and all components must be maintained in compliance with this Chapter and manufacturer
requirements.
22.3 The owner of an SSTS or the owner's agent shall regularly, but in no case less frequently than every three
years:
(1) Assess whether sewage tanks leak below the designed operating depth and whether sewage tank
tops, riser joints, and riser connections leak through visual evidence of major defects.
(2) Measure or remove the accumulation of scum, grease, and other floating materials at the top of each
septic tank and compartment, along with the sludge, which consists of solids denser than water.
22.4 All solids and liquids must be removed by pumping from all tanks or compartments in which the top of the
sludge layer is less than 12 inches from the bottom of the outlet baffle or transfer hole or whenever the
bottom of the scum layer is less than three inches above the bottom of the outlet baffle or transfer hole.
Total sludge and scum volume must not be greater than 25 percent of the tank's liquid capacity.
22.5 Removal of accumulated sludge, scum, and liquids from septic tanks and pump tanks must be through the
maintenance hole. The removal of solids from any location other than the maintenance hole is not a
compliant method of solids removal from a sewage tank, and this method does not fulfill the solids removal
requirements of this Section or a management plan. Liquid and solids removal from cleanout pips is
allowed for holding tank.
22.6 After removal of solids and liquids, from a system installed after the effective date of this Chapter, the
system shall be secured as described in Section 13.13. Covers secured by screws shall be refastened in all
screw openings.
80 Washington County Development Code
Effective September 23, 2009 Chapter Four >:< Subsurface Sewage Treatment System Regulations
22.7 After removal of solids and liquids from a system installed prior to the effective date of this Chapter covers
must:
(1) Be brought into compliance with Section 13_13 if retrofitted to be brought above the ground
surface.
(2) Be secured by covering with a minimum of 12 inches of soil.
(3) If the cover was currently at or above grade, the system must be secured by a method that was
deemed secure prior to the effective date of this Chapter.
22.8 Pump tanks must be maintained according to this part. Sludge must be removed if within one inch of the
pump intake.
22.9 When a privy is filled to one half of its capacity, the solids must be removed. Abandoned pits must have
the sewage solids and contaminated soil removed and must be filled with clean earth and slightly mounded
to allow for settling. Removed solids shall be disposed of according to Section 22.11.
22.10 Additives, which are products added to the sewage or to the system with the intent to lower the accumulated
solids in sewage, must not be used as a means to reduce the frequency of proper maintenance and removal
of sewage solids from the sewage tanks as specified in this Section. The use of additives does not fulfill the
solids removal requirement of this Section or a management plan. Additives that contain hazardous wastes
must not be used in an SSTS.
22.11 Septage or any waste mixed with septage must be disposed of in accordance with state, federal, or local
requirements for septage and other wastes. If septage is disposed of into a sewage or septage treatment
facility, a written agreement must be provided between the accepting facility and the maintenance business.
22.12 Activities on the current soil dispersal system or the reserve soil dispersal system, as defined in Section 2.2
(58) and described in Section 9.4, that impair the current or future treatment abilities or hydraulic
performance of the soil dispersal system are prohibited. This includes, but is not limited to, covering all or
part of the soil treatment system with an impermeable surface as determined by the local unit of
government.
22.13 Any maintenance activity used to increase the acceptance of effluent to a soil treatment and dispersal
system must:
(1) Not be used on a system failing to protect groundwater as defined in Sect unless the
activities meet the requirements of Section 20 or Section 21.
(2) Not decrease the separation to the periodically saturated soil or bedrock.
(3) Not cause preferential flow from the soil treatment and dispersal system bottom to the periodically
saturated soil or bedrock.
(4) Be conducted by an appropriately certified qualified employee or an appropriately licensed business
as specified in Mumeso a Rules_ Chapter %083 0790 Any substance added with the intent to
increase the infiltration rate of the soil treatment and dispersal system must not contain hazardous
substances.
22.14 Licensed maintenance businesses must maintain accurate records of pumping activity in the County and
shall report such data annually to the Department on forms provided.
81 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
22.15 MSTS must be maintained according to this Section.
2216 All external grease interceptors must be routinely inspected to determine the volume of grease present. All
external grease interceptors must be properly maintained to prevent clogging of downstream piping and
system components.
22.17 For all MSTS constructed after the effective date of this Chapter, the designer must complete an operation
and maintenance manual and the manual must be submitted to the Department or the local unit of
government before system operation. The manual shall include a copy of the plans and specifications, as-
built drawings of the system, and information to properly operate the system.
22.18 All new MSTS shall be operated under a local operating permit submitted and approved with the design.
22.19 All groundwater shall be monitored in accordance with Section 1.1.
22.20 Any operational noncompliance must be immediately corrected and reported by the owner or service
provider to the Department or local unit of government.
82 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
SECTION 23 SYSTEM ABANDONMENT
23.1 All systems with no future intent for use must be abandoned according to this Section. Tank abandonment
procedures for sewage tanks, cesspools, leaching pits, drywells, seepage pits, vault privies, pit privies, and
distribution devices must meet the requirements of Section 23.1 (1) to Section 23.1 (31.
(1) All solids and liquids must be removed and disposed of according to Section 22 by a Iicensed
maintenance business.
(2) All electrical devices and devices containing mercury must be removed and disposed of according
to applicable regulations.
(3) Abandoned tanks or any other underground cavities must be removed or remain in place and
crushed with the remaining cavity filled with soil or rock material.
(4) The removed tank or tank fragments and any soil visually contaminated with sewage shall be
disposed in accordance with Section 23.3.
23.2 Access for future discharge to the system must be permanently denied.
23.3 If soil treatment and dispersal systems are removed, contaminated materials shall be properly handled to
prevent human contact. Contaminated materials include distribution media, soil or sand within three feet of
the system bottom, distribution pipes, tanks, and contaminated soil around leaky tanks. Contaminated
material also includes any soil that received sewage from a surface failure. Contaminated materials must be
disposed of according to Section 23.3 (1) to Section 233 (2).
(1) Contaminated materials disposed of offsite must be disposed of according to Section 22.11
(2) If contaminated material is to be spread or used on site within one year of contact with sewage, the
material must be placed in an area meeting the soil and setback requirements described in Table V
in Section 16 and Section '16.3 (31 of this Chapter and the material must be covered with a
minimum of six inches of uncontaminated soil and protected from erosion. After one year
following contact with sewage, the material is allowed to be spread in any location meeting the
setback requirement of Minnesota Rules Chapter 4725,4450, covered with a minimum of six
inches of uncontaminated soil, and protected from erosion. After one year following contact with
sewage, the material is allowed to be used to fill in the abandoned in place sewage tanks.
(3) Contaminated pipe, geotextile fabric, or other material must be dried and disposed of in a mixed
municipal solid waste landfill.
23.4 The person or business abandoning the system must complete and sign a record of abandonment that states
the system was abandoned according to this Section. A description of the abandonment procedure must be
recorded including a map of the remaining in -place components and location of the components removed.
The record must be sent to the Department or local unit of government within 90 days of abandonment.
23.5 MSTS no longer in use must be abandoned according to this Section.
Effective September 23, 2009 Chapter Four S• Subsurface Sewage Treatment System Regutations
SECTION 24 PRODUCT REGISTRATION
24.1 All product registration shall be in accordance with Minnesota Rules 7083.4000 to 7083.4120.
24.2 Technology and products employed in system design shall adequately protect the public health and the
environment as determined by Minnesota Rules, Chapter 7083, and be approved for use by the Department
or local unit of government.
84 Washington County Development Code
Effective September 23, 2009 Chapter Four Subsurface Sewage Treatment System Regulations
SECTION 25 ENFORCEMENT
25.1 It is hereby declared unlawful for any person, firm or corporation to violate any term or provision of this
Chapter. Violation thereof shall be a misdemeanor. Each day that a violation is allowed to continue shall
constitute a separate offense.
25.2 In the event of a violation or threatened violation of this Chapter, the Department, in addition to other
remedies, may request appropriate actions or proceedings to prevent, restrain, correct or abate such
violations or threatened violations. In addition, written notice in the form of a license complaint may be
made to the Commissioner of the Minnesota Pollution Control Agency.
25.3 In cases where a public health nuisance has been determined to exist, the Department may institute
enforcement action under the Local Public Health Act Minnesota Statutes Chapter 145A and the
Washington County Public Health Nuisance Ordinance Washin ton County Ordinance No 165, or
subsequent revisions there to.
SECTION 26 SEPARABILITY
26.1 It is hereby declared to be the intent that the several provisions of this regulation are separable in
accordance with the following:
(1) If any court of competent jurisdiction shall adjudge any provision of the regulation to be invalid,
such judgment shall not affect other provisions of this regulation not specifically included in said
judgment.
(2) If any court of competent jurisdiction shall adjudge invalid the application of any provision of this
regulation to a particular property, building or structure, such judgment shall not affect the
application of said provision to any other property, building or structure not specifically included in
said judgment.
SECTION 27 EFFECTIVE DATE
27.1 The regulations contained in this Chapter shall become effective from and after September 23, 2009, after
their publication according to law.
85 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
APPENDIX A SOIL LOADING RATES FOR LEVEL C TREATMENT
Loading Rates for Determining Bottom Absorption Area for Trenches and Seepage Beds for
Effluent Treatment Level C and Absorption Ratios for Determining Mound Absorption Area
using Detail Soil Descriptions
Texture
Texture
Group
Structure
Consistence
Soil
Loading
Rate
(gpd/fe)
Mound
Absorption
Ratio
Type
Grade
Loose
1.0
Coarse
Sandy'
I
Single
Grain
Structureless
Weakly Cemented
Friable
2.0
Cemented -Finn
-
Loose
1.20
1.0
Medium
Sand*
Single
Grain
Structureless
Weakly Cemented
Friable
0.60
2.0 j
Cemented -Firm
Loose
0.60
2.0
Fine Sand
3
Single
Grain
Structureless
Weakly Cemented
Friable
0.24
5.0
Cemented -Finn
-
Coarse and
Loose
1.20
1.0
Weakly Cemented
Friable
0.60
2.0
Medium
Loamy
4
Single
Grain
Structureless
Cemented -Firm
-
Sand*
Fine and
Very Fine
Loamy Sand
5
Single
Grain
Structureless
Structureless
Loose
0.60
2.0
Weakly Cemented
0.24
5.0
Cemented -Firm
-
j
Prismatic,
Blocky,
Granular
Wei
Very Friable, Friable
0.45
2.6
Finn
0.24
50
Moderate or
Strong
--
Very Friable, Friable
0.78
1.3
Firm
0.45
2.6
Coarse and
Medium
Sandy Loam
6
Platy
Wei
Very Friable, Friable
0.45
2.6
Finn
0.24
5.0
Moderate or
Very Friable, Friable
0.45
2.6
Finn
-
-
Strong
Massive
Structureless
Very Friable, Friable
0.24
5.0
Firm
86 Washington County Development Code
Effective September 23, 2009 Chapter Four v Subsurface Sewage Treatment System Regulations
Loading Rates for Determining Bottom Absorption Area for Trenches and Seepaile Beds fo r
Effluent Treatment Level C and Absorption Ratios for Determining Mound Absorption Areas
using Detail Soil Descriptions
Texture
Texture
Group
Structure
Consistence
Soil
� Loading
Rate
( d/f 2
Mound
Absorption
Ratio
Type
Grade
Fine and
Very Fine
Sandy Loam
7
Prismatic,
Blocky,
Granular
Weak
Very Friable, Friable
0.24
5.0
Firm
0.24
5.0
Moderate or
Strong
Very Friable, Friable
0.60
2.0
fim
0.24
5.0
Platy
Plat
Weak
Very Friable, Friable
0.24
5.0
Finn
-
_
Moderate or
Strong
Very Friable, Friable
_
Finn
_
Massive
Structureless
Very Friable, Friable
0.24
5.0
Firm
Loam
S
Prismatic,
Blocky,
Granular
Weak
Very Friable, Friable
0.45
2.6
Firm
0.24
5.0
Moderate or
Strong
Very Friable, Friable
0.60
2.0
Finn
0.24
5.0
Platy
I Weak
Very Friable, Friable
0.24
5.0
Firm
Moderate or
Strong
Very Friable, Friable
-
Firm
Massive
Structureless
Very Friable, Friable
0.24
5.0
Firm
Silt Loam
y
Prismatic
Blocky,
Granular
Weak
Very Friable, Friable
0.45
2.6
Firm
0.24
5.0
Moderate or
Strong
Very Friable, Friable
0.50
2.4
Firm
0.24
5.0
Platy
Weak
Very Friable, Friable
0.24
5.0
Finn
-
_
Moderate or
Strong
Very Friable, Friable
Firm
_
_
Massive
Structureless
Very Friable, Friable
0.24
5.0
Finn
_
87 Washington County Development Code
Effective September 23, 2009 Chapter Four :• Subsurface Sewage Treatment System Regulations
Loading Rates for Determining Bottom Absorption Area for Trenches and Seepage Beds for
Effluent Treatment Level C and Absorption Ratios for Determining Mound Absorption Areas
using Detail Soil Descriptions
Texture
Texture
Group
Structure
Consistence
Soil
Loading
RateZ
( d /ft )
Mound
Absorption
Ratio
Type
Grade
Clay Loam,
Prismatic,
Blocky,
Granular
Weak
Very Friable, Friable
0.24
5.0
Firm
-
-
Moderate or
Strong
Very Friable, Friable
0.45
2.6
Finn
0.24
5.0
Silty Loam, Clay
oamlay
Sandy Clay
Loam
10
Platy
Weak
Very Friable, Friable
Firm
-
-
Moderate or
Very Friable, Friable
-
-
Finn
-
Strong
Massive
Structure less
Very Friable, Friable
-
Finn
-
Prismatic,
Blocky,
Granular
Weak
Very Friable, Friable
-
Firm
-
Moderate or
Strong
Very Friable, Friable
0.24
5.0
Firm
-
-
Clay, Silty
Clay, Sandy
Clay
11
Platy
Weak
Very Friable, Friable
-
Finn
Moderate or
Very Friable, Friable
-
-
Strong
Finn
-
-
Massive
Structureless
Very Friable, Friable
-
-
Firm
-
-
88 Washington County Development Code
Effective September 23, 2009 Chapter Four ❖ Subsurface Sewage Treatment System Regulations
APPENDIX B SOIL LOADING; RATER VOU i.FVFT A x, R •rPF A rnARivm
Loading Rates for Determining Bottom Absorption Area for Trenches and Seepage Beds for
Effluent Treatment Level A and Level B and Absorption Ratios for Determining Mound
Absorption Areas usin Detail Soil Descriptions
Texture
Texture
Group
Structure
Type Grade
Consistence
Soil
Loading
Rate
(gpd1 t2)
Mound
Absorption
Ratio
Coarse Sand*
1
Single Grain
Structureless
Loose
1.0
Weakly Cemented Friable
2.0
Cemented -Firm
Medium Sand*
2
Single Grain
Structureless
Loose
1.60
1.0
Weakly Cemented Friable
( 0.78
2.0
Cemented -Firm
Fine Sand
3
Single Grain
Structureless
Loose
1.00
2.0
Weakly Cemented Friable
0.12
2.0
Cemented -Firm
_
Coarse and
Medium
Loamy Sand*
4
Single Grain
Structureless
Loose
1.60
1.0
Weakly Cemented Friable
0.78
2.0
Cemented -Firm
Fine and Very
Fine Loamy
Sand
5
Single Grain
Structureless
Loose
1.00
2.0
Weakly Cemented Friable
0.45
5.0
Cemented -Firm
Coarse and
Medium Sandy
Loam
6
Prismatic,
Blocky,
Granular
Weak
Very Friable, Friable
0.60
2.6
Firm
0.45
5.0
Moderate or
Strong
Very Friable, Friable
1.00
1.3
Firm
0.60
2.6
Platy
Weak
Very Friable, Friable
0.60
2.6
Firm
0.45
5.0
Moderate or
Strong
Very Friable, Friable
0.60
2.6
Firm
Massive
Structureless
Very Friable, Friable
0.45
5.0
Firm
_
89 Washington County Development Code
Effective September 23, 2009 Chapter Four d• Subsurface Sewage Treatment System Regulations
Loading Rates for Determining Bottom Absorption Area for Trenches and Seepage Beds for
Effluent Treatment Level A and Level B and Absorption Ratios for Determining Mound
Absorption Areas using Detail Soil Descriptions
Texture
Texture
Group
Structure
Consistence
Soil
Loading
Rate
(gpd /ft2)
Mound
Absorption
Ratio
Type
Grade
Prismatic,
Blocky,
Weak
Very Friable, Friable
0.45
5.0
Firm
0.45
5.0
Granular
Moderate or
Very Friable, Friable
0.78
2.0
fim
0.45
5.0
Strong
Fine and Very
Fine Sandy
7
Weak
Very Friable, Friable
0.45
5.0
Loam
Platy
Firm
0.00
Moderate or
Very Friable, Friable
0.24
Strong
Firm
Massive
Structureless
Very Friable, Friable
0.45
5.0
Firm
Prismatic,
Blocky,
Weak
Very Friable, Friable
0.60
2.6
Firm
0.45
5.0
Granular
Moderate or
Very Friable, Friable
0.78
2.0
Firm
0.45
5.0
Strong
Weak
Very Friable, Friable
0.45
5.0
Loam
8
Firm
Ptaty
Moderate or
Very Friable, Friable
0.24
Strong
Firm
Massive
Structureless
Very Friable, Friable
0.45
5.0
Firm
Prismatic,
Blocky,
Weak
Very Friable, Friable
0.60
2.6
Firm
0.45
5.0
Granular
Moderate or
Very Friable, Friable
0.78
2.4
Firm
0.45
5.0
Strong
Weak
Very Friable, Friable
0.45
5.0
Silt Loam
9
Firm
Platy
Moderate or
Very Friable, Friable
Strong
Firm
-
Massive
Structureless
Very Friable, Friable
0.30
5.0
Firm
90 Washington County Development Code
Effective September 23, 2009 Chapter Four •.< Subsurface Sewage Treatment System Regulations
Loading Rates for Determining Bottom Absorption Area for Trenches and Seepage Beds for
Effluent Treatment Level A and Level B and Absorption Ratios for Determining Mound
Absorption Areas usin Detail Soil Descriptions
Texture
Texture
Group
Structure
Type Grade
Consistence
Soil
Loading
Rate
(gpd /ft')
Mound
Absorption
Ratio
Clay Loam,
Silty Clay
Loam, Sandy
Clay Loam
10
Prismatic,
Blocky,
Granular
Weak
Very Friable, Friable
0.30
5.0
Firm
_
Moderate or
Strong
Very Friable, Friable
0.60
2.6
Firm
0.30
5.0
Platy
Weak
Very Friable, Friable
Firm
Moderate or
Strong
Very Friable, Friable
Firm
Massive
Structuretess
Very Friable�Friabte
i
Firm
Clay, Silty
Clay, Sandy
Clay
11
Prismatic,
Btocky,
Granular
Weak
Very Friable, Friable
Firm
Moderate or
Strong
Very Friable, Friable
030
5.0
Firm
Platy
Weak
Very Friable, Friable
-
Firm
Moderate or
Strong
Very Friable, Friable
Firm
Massive
Structureless
Very Friable, Friable
Firm
Footnotes: The Department's interpretation of Chapter Four is as follows:
1. This Department adopted Table IX in Minnesota Rules 7080.2150 as now constituted and from time to time
amended.
2. This Department adopted Minnesota Rules 7080.1910 to 7080.2020 as now constituted and from time to
time amended.
3. This Department adopted Minnesota Rules 7080.2050 as now constituted and from time to time amended.
4. This Department adopted Table XII in Minnesota Rules 7080.2350 as now constituted and from time to
time amended.
5. All trenches and seepage beds in accordance with Minnesota Rules, Chapter 7080.2050, as now constituted
and from time to time amended.
6. If the distribution media is in contact with soil with soil texture groups 2 or 3 in Table IX in Minnesota
Rules, Chapter 7080.2150' or a percolation rate of 0.1 to 5.0 minutes per inch in Table VI, the distribution
of effluent must comply with Minnesota Rules, Chapter 7080.2060, as now constituted and from time to
time amended.
91 Washington County Development Code
BOARD OF COUNTY COMMISSIONERS 2009 -089
WASHINGTON COUNTY, MINNESOTA RESOLUTION N0.
DATE September 8, 2009 DEPARTMENT Public Health & Environment
MOTION
BY COM
SECONDED BY
COMMISSIONER
Kriesel
RESOLUTION ADOPTING AN AMENDMENT TO THE WASHINGTON COUNTY DEVELOPMENT CODE,
CHAPTER FOUR, SUBSURFACE SEWAGE TREATMENT SYSTEM REGULATIONS
WHEREAS, the Minnesota Pollution Control Agency (MPCA) revised Minnesota Rules, Chapter 7080,
Individual Sewage Treatment System Program, into Minnesota Rules, Chapters 7080 through 7083,
Subsurface Sewage Treatment System Program, on February 4, 2008; and
WHEREAS, Minnesota Rules, Chapter 7082, Section 7082.0050, Subpart 1, Paragraph B requires that
the County update its ordinance by February 4, 2010; and
WHEREAS, the most recent version of this ordinance is Washington County Ordinance No. 128,
Individual Sewage Treatment System Regulations, adopted by the County Board on October 20, 1997; and
WHEREAS, on October 14, 2008, a presentation was made by the Department of Public Health and
Environment to the County Board to review proposed changes to the Ordinance; and
WHEREAS, on June 23, 2009, the Washington County Planning Advisory Commission referred the
Subsurface Sewage Treatment System Regulations in the form of Chapter Four of the Washington County
Development Code to the County Board with their recommendations; and
WHEREAS, on September 8, 2009, the Washington County Board of Commissioners conducted a
public hearing to consider adopting Chapter Four of the Washington County Development Code,
NOW, THEREFORE, BE IT RESOLVED, that the Washington County Board of Commissioners hereby
adopts Washington County Subsurface Sewage Treatment System Ordinance No. 179 to take effect upon the
passage of this resolution and its publication according to law.
NOW, THEREFORE, BE IT FURTHER RESOLVED, that Washington County Ordinance No. 128 is
hereby replealed, said repeal to take effect on the date Washington County Ordinance No. 179 becomes
effective.
ATTEST: it
C NNTY ADMINISTRATOR .
CHAIRMAN, 'COUNTY BOARD
WEIK x
July 2002
http: /!wash net /forms /Cou ntyad /Res of ut ion. d of
YES NO
HEGBERG
X
KRIESEL
g
PETERSON
g
PULKRABEK
g
WEIK x
July 2002
http: /!wash net /forms /Cou ntyad /Res of ut ion. d of
•
DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
GOVERNMENT CENTER
14949 62nd STREET NORTH P.O. BOX 6 STILLWATER, MN 55082 -0006
Office: 651- 430 -6655 TDD: 651- 430 -6246 FAX: 651- 430 -6730
Visual Inspection (note any problems with the system): NOTE: This does not serve as a compliance inspection.
*Tank Measurements -Use Only IfTank(s) Were NOT Pumped
Tank Length in. X Tank Width in. X Tank Depth in. = Tank Volume (cubic inches)
Tank Radius in. X Tank Radius in. X 3.14 = Tank Volume (cubic inches)
Tank Volume (cu. in.) / 231.01 = Liquid Capacity Gallons/ Tank Depth in. = Gallons /Inch
Sludge Level in. X Gallons Per Inch = Sludge Volume Gallons
Scum Level in. X Gallons Per Inch = Scum Volume Gallons
Sludge Volume + Scum Volume = Total Sludge and Scum Volume Gallons
Total Sludge and Scum Volume / Liquid Capacity = Percent Sludge and Scum in Tank %
Scum Layer
Effluent
Sludge Layer
Signature
Tank Depth measured
from invert of outlet
pipe to bottom of tank
Date
*Tanks must be pumped if either of the
following conditions exist:
1. The top of the sludge layer is less than
12 inches from the bottom of the outlet
baffle; or
2. Total sludge and scum volume is greater
than 25 percent of the tank's liquid
capacity.
Reset Form
;System Location
Address
Telephone Number
City
State ZIP
Property ID No. /GEO Code
Owner
Pumping Date
Contractor
Maintainer
MPCA License No.
Telephone Number
What was done to the system?
Report Liquid Capacity in Gallons
❑ Tank(s) Pumped
❑ Sludge and scum measured.
Do tanks need to be pumped?
❑ Yes ❑ No (Ifno provide measurements below)
Tank 1: ❑ Pumped Tank 2: ❑ Pumped
Tank 3: ❑ Pumped Tank 4: ❑ Pumped
Total Gallons Pumped:
Visual Inspection (note any problems with the system): NOTE: This does not serve as a compliance inspection.
*Tank Measurements -Use Only IfTank(s) Were NOT Pumped
Tank Length in. X Tank Width in. X Tank Depth in. = Tank Volume (cubic inches)
Tank Radius in. X Tank Radius in. X 3.14 = Tank Volume (cubic inches)
Tank Volume (cu. in.) / 231.01 = Liquid Capacity Gallons/ Tank Depth in. = Gallons /Inch
Sludge Level in. X Gallons Per Inch = Sludge Volume Gallons
Scum Level in. X Gallons Per Inch = Scum Volume Gallons
Sludge Volume + Scum Volume = Total Sludge and Scum Volume Gallons
Total Sludge and Scum Volume / Liquid Capacity = Percent Sludge and Scum in Tank %
Scum Layer
Effluent
Sludge Layer
Signature
Tank Depth measured
from invert of outlet
pipe to bottom of tank
Date
*Tanks must be pumped if either of the
following conditions exist:
1. The top of the sludge layer is less than
12 inches from the bottom of the outlet
baffle; or
2. Total sludge and scum volume is greater
than 25 percent of the tank's liquid
capacity.
Reset Form