HomeMy WebLinkAboutFINAL ORDINANCE NO. 97-022CITY OF LAKE ELMO
WASHINGTON COUNTY, MINNESOTA
ORDINANCE 97- 22
AN ORDINANCE ADDING SECTION 720
ALTERNATE WASTE DISPOSAL SYSTEM — WETLAND TREATMENT SYSTEM
TO THE 1997 LAKE ELMO MUNICIPAL CODE
Section 1. Amendment: Section 720 of the 1997 Municipal Code is hereby added and shall
read as follows:
Section 720 - Alternative Waste Disposal Systems - Wetland Treatment Systems
720.01 Title.
This Section shall be known, cited and referred to as the Alternative Waste Disposal System
ordinance.
720.02 Intent and Purpose.
Subd. 1 Health. Safety, and Welfare.
The purpose of this section is to protect the health, safety, and welfare of the residents of the
community, present and future.
Subd. 2 Contamination of Surface/Ground Water.
The purpose of this section is to regulate the location, design, installation, use, and
maintenance of alternative waste disposal systems so as to prevent the contamination of the
surface and ground water within the community.
Subd. 3 Contamination of Private Water Supply Wells.
The intent of this section is to protect the individual water supply wells of the community from
contamination by inadequate, improperly designed, located, installed or maintained individual
and community sewage treatment systems.
Subd. 4 Open Space Development.
The intent of this section is to allow subsurface flow - "wetland treatment" systems to be an
allowed alternative system within cluster developments.
720.03 Rules.
Subd. 1 Specifications Which Apply.
Lake Elmo Municipal Code Section 700 shall apply.
Subd. 2 Location of Systems.
A. Setbacks. All components of a wetland treatment system within a new residential or
commercial development, with a design flow of 1500 gallons per day or more, including
stilling tanks, pump stations, and treatment cells shall be located a minimum of 100 feet
from any property line, and 200 feet from any existing or proposed home. Stilling tanks
may however be located 50 feet from a street right-of-way.
Wetland treatment systems used to replace failed septic systems, and those with less than
a 1500-gallon per day design flow shall have setbacks considered reasonable for the site
and the neighboring properties.
B. Groundwater. Treatment cells shall have a minimum of 3 feet between the bottom of
the cell and the ground water table. Drain tile or French drains shall not be used to
artificially lower the groundwater table.
Subd. 3 System Design.
A. Designer. Wetland treatment systems shall be designed by a Registered Professional
Engineer with experience and specific training in the design of these types of systems.
B. Design Flow. Wetland treatment systems shall be sized based on a minimum of 50
gallons per day per person.
C. Level of Treatment. Wetland treatment systems shall be designed to remove Total
Suspended Solids (TSS), Phosphorous (P), Total Nitrogen (TN), and Fecal Coliforms
(FC), and reduce the 5-Day Carbonaceous Biochemical Oxygen Demand (CBODS).
Calculations showing the design level of treatment shall be submitted.
Prior to discharge into the infiltration cell, the following discharge limits shall be met:
CBODS
50mg/l
TSS
20mg/l
TN
15mg/1
N114
10mg/l
TP
5mg/1
FC
200mg/1
In the ground water below the infiltration cell, the following discharge limits shall be
met:
TN 10mg/1
FC 4 c/100 ml
D. Insection Points. Inspection and monitoring ports shall be located within the system
such that the water level can be determined, and a water sample can be easily taken in
each treatment cell, and 1- foot below the infiltration cell.
E. Operating Plan. An operating plan shall be developed by the designer. This plan
shall include standard operating procedures and maintenance of the system.
F. Monitoring Plan. Systems designed for greater than 1500 gallons per day shall have a
monitoring plan developed by the designer. It shall include monitoring of sludge and
scum levels in the septic tanks and pumping stations, effluent flow into the system.
Water quality exiting the fast treatment cell shall be monitored to insure that it meets the
design level of treatment. Monitoring of the groundwater below the second treatment cell
shall also be performed. Monitoring shall be conducted annually.
The City shall be sent a copy of all test results. An annual fee shall be charged by the
City to review these test results. This fee shall be set from time to time by resolution of
the City Council.
G. Mitigation Plan. The system designer shall develop a plan to follow in case expansion
or abandonment of the system is necessary.
H. City Review. The City shall review and approve all parts of the system design and
associated plans prior to any construction taking place. Once approval of the system is
given, a permit shall be issued by the City.
Subd.4 Construction.
A Sanitary Sewers. All sanitary sewers shall be constructed and tested in accordance
with the City Engineers Association of Minnesota Standards for Utility Construction.
B. Treatment Cells - Testinn. Liners of treatment cells shall be visually inspected for
tears, holes, or poor seams prior to placing rock. A leak test shall be performed after the
rock is in placed. The liner shall be uncovered, repaired and the test rerun if any leaks
show up during this testing.
A City representative shall be present for all treatment cell testing.
C. Turf Establishment/ Plant Growth. The Designer shall prepare a vegetation plan to
establish a wetland community over the treatment cells.
Prior to final acceptance, wetland plants shall display vigorous growth, and turf shall be
established outside of the treatment cell area. No erosion shall be present on the site.
D. Certification. The system designer shall certify in writing to the City that the
treatment system has been constructed in accordance with the approved plans and
specifications, and that all test requirements have been met. This certification must be
received before start-up of the system.
:Sa
Wyn John,
Attest
te: This ordinance shall become effective upon its passage and
law.
Mary Kueffner, City Clerk/Administrator
Published in the Stillwater Gazette on the
6 L day of� 19se
City of Lake Elmo
Washington County, Minnesota
Summary of Ordinance 97-22.
Relating to Alternative Waste disposal Systems
Wetland Treatment Systems
On January 6, 1998 the Lake Elmo City Council adopted Ordinance 97-22- relating to Alternative
Waste disposal Systems - Wetland Treatment Systems
On January 6, 1998, the Lake Elmo City Council received a summary of Ordinance 97- 22 and by
ij affirmative votes, approved the publication of a summary of this ordinance, to wit:
Section 720 - Alternative Waste Disposal Svstems - Wetland Treatment Svstems
720.01 Title.
720.02 Intent and Purpose.
Subd. 1 Health, Safety, and Welfare.
Subd. 2 Contamination of Surface/Ground Water.
Subd. 3 Contamination of Private Water Supply Wells.
Subd. 4 Open Space Development.
720.03 Rules.
Subd. 1 Specifications Which Applv.
Subd. 2 Location of Systems.
Subd. 3 System Design.
Subd.4 Construction.
A complete copy of Ordinance 97-22. " Alternative Waste disposal Systems
Wetland Treatment Systems" is on file in the office of the City Administrator/Clerk and can be
viewed � th,�public d�.yyug normal business hours.
4
Wyn 4ha,Mwj;e --�
Attest: (/
Mary Kueffner, City Administrator/Clerk
PUBLISIIED IN THE MAY 6, 1998 STILLWATER GAZETTE