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P:\Projects\Projects - 2023\12236128 - New Stillwater Elementary School - Wold\C. Design\Drawing Files\12236128 - C001 SWPPP.dwg
<br /> 08-23-2024 PRELIMINARYPLAT SUBMITTALRevisionsDescriptionDateNumNorthCheck:Drawn:Date:Comm:MTH08-23-2024122361283524 Labore RoadWhite Bear Lake, MN 55110651.481.9120 (f) 651.481.9201www.larsonengr.comC 2024 Larson Engineering, Inc. All rights reserved.3524 Labore RoadWhite Bear Lake, MN 55110651.481.9120 (f) 651.481.9201www.larsonengr.comLarsonEngineering, Inc.Greg A. Buchal, P.E.Date: Lic. No.:08.23.202423793I hereby certify that this plan, specifications or reportwas prepared by me or under my direct supervisionand that I am a duly licensed Professional Engineerunder the laws of the state of Minnesota.INDEPENDENT SCHOOLDISTRICT #834New Lake ElmoElementary School1875 Greeley St S, Stillwater, MN55082Corner of 10th Streen North andLake Elmo Avenue NorthLake Elmo MN 55042AFEDCBA12345678MNPROJECT SPECIFIC SWPPP INFORMATION:I.GENERAL CONSTRUCTION ACTIVITY INFORMATIONPROJECT NAME:NEW LAKE ELMO ELEMENTARY SCHOOLPROJECT LOCATION:NORTH EAST CORNER OF THE INTERSECTIONOF LAKE ELMO AVE N. AND 10TH STREET N.LAKE ELMO, MN 55042PROJECT CONTACTSOWNER:INDEPENDENT SCHOOL DISTRICT #8341875 GREELEY STREET SOUTHSTILLWATER, MN 5508CONTACT:ENGINEER:LARSON ENGINEERING, INC.3524 LABORE ROADWHITE BEAR LAKE, MN 55110CONTACT: MITCH HONSA, P.E., 651-481-92120, MHONSA@LARSONENGR.COMCONTRACTOR:COMPANY (TBD)ADDRESSCITY, STATE, ZIPCONTACT: NAME, PHONE, EMAILCITY WHERE WORK WILL TAKE PLACE:LAKE ELMO, MNCOUNTY WHERE WORK WILL TAKE PLACE:WASHINGTONLATITUDE/LONGITUDE OF APPROXIMATE CENTROID OF PROJECT:45° 57' 53" N, 92° 53' 06" WPROJECT TYPE (CIRCLE ONE):RESIDENTIALCOMMERCIAL/INDUSTRIALROAD CONSTRUCTIONRESIDENTIAL & ROAD CONSTRUCTIONOTHER (DESCRIBE): SCHOOLDATES OF CONSTRUCTION (ESTIMATED):Construction start date:10/2024Construction completion date:10/2026PROJECT DESCRIPTION:The project will consist of the construction of a new school building, parking lots, drives, sidewalks,athletic fields, stormwater basins, and related utilities. There are no wetland impacts associated withthe project.PROJECT LIMITS:See the project plans, in particular the grading & erosion control plans, for site disturbance limits.SITE DISTURBANCE SUMMARY (to nearest tenth acre):Total number of acres to be disturbed:34.9Pre-Construction acres of impervious:0.0Post-Construction acres of impervious:8.6Total new impervious acres:8.6II.RECEIVING WATERSRECEIVING WATERS (WITHIN ONE MILE OF PROJECT PROPERTY EDGE):NAME OF WATER BODYTYPESPECIAL WATER?IMPAIRED WATER?Goose Lake (South)LakeNoYesLake ElmoLakeNoYes (Mercury)Horse Shoe LakeLakeNoNoRoseLakeNoNoKramerLakeNoNoH.J. Brown PondPondNoYes (PFOS)MargaretLakeNoNoTOTAL MAXIMUM DAILY LOAD (TMDL) WATERSN/AIDENTIFY WETLAND IMPACTS:1.Will construction result in any potential adverse impacts to wetlands, including excavation,degradation of water quality, draining, filling, permanent inundation or flooding, conversion to astormwater pond?No.If yes, describe impacts and mitigation measures that were taken to address the impacts and includecopies of permits or approvals from an official state wide wetland program issued specifically for thisproject or site:N/AENVIRONMENTALLY SENSITIVE AREAS:1.Identify adjacent public waters where the MN DNR has declared "work in water restrictions" duringfish spawning timeframes:None identified.2.Describe any stormwater mitigation measures that will be implemented, as a result of anenvironmental review, endangered or threatened species review or archeological site review:N/AIII.PROJECT PLANS AND SPECIFICATIONSRefer to the project plans, specifications, geotechnical report, and stormwater calculations which depict variousfeatures that are relevant to this project. Such features may include, but are not limited to, the following:·Project location and construction limits.·Existing and final grades, including dividing lines and direction of flow for all pre and post-constructionstormwater runoff drainage areas located within the project limits.·Soil types at the site.·Locations of impervious surfaces.·Locations of areas not to be disturbed (e.g., buffer zones, wetlands, etc.)·Steep slope locations.·Locations of areas where construction will be phased to minimize duration of exposed soils.·Locations of all temporary and permanent erosion control and sediment control best management practices(BMP's).·Buffer zones as required in item 9.17 and 23.11 of the permit.·Locations of potential pollution-generating activities identified in Section 12 of the permit.·Standard details for erosion and sediment control BMP's to be installed at the site.The anticipated erosion prevention and sediment control BMP quantities needed for the life of this projectinclude the following. These quantities are estimated only and shall be verified by the Contractor.BMPEstimated QuantityFinal QuantityRock Construction EntranceSilt FenceInlet ProtectionConcrete WashoutFES Outlet Rip-RapTurf SeedingErosion BlanketSOIL INFORMATIONRefer to geotechnical report for site specific soil information.TEMPORARY SEDIMENT CONTROL (SITE SPECIFIC ITEMS)1.Is the project required to install a temporary sediment basin due to 10 or more acres draining to acommon location, or 5 acres or more if the site is located within 1 mile of a special or impaired water?No.If yes, describe (or attach plans) showing how the basin will be designed and constructed in accordancewith Section 14.N/A2.Will the project include dewatering, basin draining?No.If yes, describe measures to be used to treat/dispose of turbid or sediment-laden water and method toprevent erosion or scour of discharge points (see Section 10 of the permit):N/A. Based on soil boring results, dewatering is not anticipated.3.Will the project include use of filters for backwash water?No.If yes, describe how filter backwash water will be managed on the site or properly disposed of:N/APERMANENT STORMWATER MANAGEMENT (SITE SPECIFIC ITEMS)1.Will the project result in one acre or more of new impervious surface or result in one acre or more of newimpervious in total if the project is part of a larger plan of development?Yes.If yes, a water quality volume of one inch of runoff from the cumulative new impervious surfaces must beretained on site (Section 15) through infiltration unless prohibited due to one of the reasons in item 16.14through 16.21. If infiltration is prohibited, identify other methods of stormwater treatment used (e.g. filtration,wet sedimentation basin, regional ponding, or equivalent method):Three new infiltration basins are being proposed as part of the project to provide the required waterquality volume from the total new and fully reconstructed impervious areas.2.Attach design parameters for the planned permanent stormwater management system, including volumecalculations, discharge rate calculations, construction details including basin depth, outlet configurations,location, design of pre-treatment devices, and timing for installation.See the project plans and stormwater calculations.3.For infiltration systems, provide at least one soil boring, test pit, or infiltrometer test in the location of theinfiltration practice for determining infiltration rates.See the geotechnical evaluation reports contained within the stormwater calculations. Additionalin-field testing and geotechnical observations are planned during construction to verify soilcharacteristics at the proposed basin location.4.For projects that discharge to trout streams, including tributaries to trout streams, identify method ofincorporating temperature controls into the permanent stormwater management system.N/ASEQUENCE OF CONSTRUCTION ACTIVITIES1.Install stabilized rock construction entrances.2.Install perimeter erosion control BMP's (silt fence, bio-logs, etc).3.Install temporary construction fencing at infiltration areas and other areas not be disturbed.4.Install inlet protection throughout project area and downstream inlets.5.Construct temporary sediment basins/traps as necessary.6.Strip and stockpile topsoil.7.Complete rough grading of site.8.Stabilize denuded areas and stockpiles.9.Install site utilities.10.Install temporary inlet protection at newly installed catch basins/inlets.11.Install curb and gutter and pavement sections.12.Place topsoil and final grading of areas to be vegetated.13.Remove accumulated sediment from basins / ponds.14.Final grade pond and infiltration areas, including soil de-compaction as specified.15.Complete stormwater basin as-built surveys (as required by project specifications and/or localjurisdictional authorities).16.Complete permanent stabilization including plantings, seeding, and mulch.17.Upon completion of construction activity and satisfactory vegetation establishment, remove remainingtemporary erosion and sediment control BMPs.18.Reseed / restore any areas disturbed during BMP removal.SEEDING NOTES AND REQUIREMENTS:1.The Contractor is responsible to salvage and preserve existing topsoil as necessary for final stabilization.All topsoil to be salvaged and re-used shall be processed as necessary to meet project specifications.2.Prior to final seeding, all areas to be vegetated shall be scarified/decompacted and amended as specifiedin the plans and specifications.3.Unless otherwise noted, all seed mixes and applications shall be in accordance with MNDOT SeedingManual, latest edition.4.See the project plans and specifications for seed mixtures, mulch, slope stabilization, and all otherlandscaping requirements.FINAL STABILIZATION:Ensure Final Stabilization of the site. Final Stabilization is not complete until all of the following requirements arecomplete:1.All soil disturbing activities at the site have been completed and soils are stabilized by a uniform perennialvegetative cover with a density of 70 percent of its expected final growth over the entire pervious surfacearea, or other equivalent means necessary to prevent soil erosion under erosive conditions.2.The permanent stormwater management system is constructed and operating as designed. Temporary orpermanent sedimentation basins that are to be used as permanent water quality management basinshave been cleaned of any accumulated sediment. All sediment has been removed from conveyancesystems and ditches are stabilized with permanent cover.3.All temporary synthetic and structural erosion prevention and sediment control BMPs (such as silt fence,bio-logs, etc.) have been removed from the site. BMPs designed to decompose on site may be left inplace.4.Upon correction of all erosion and sediment items and achieving vegetative cover, temporary erosionprevention and sediment control BMPs will be removed and properly disposed/recycled.5.Within 30 days of final stabilization, a notice of termination shall be submitted to the MPCA (see PermitTermination Req's) .GENERAL SWPPP NOTES:1.The Contractor and all Subcontractors involved with construction activity that disturbs soil, or implementsa pollution control measure as part of the Storm Water Pollution Prevention Plan (SWPPP) for this project,must comply with the requirements of the National Pollution Discharge Elimination System (NPDES) /State Disposal System (SDS) Program, General Permit MNR10001, Dated August 1, 2023.2.The Contractor and all Subcontractors shall be responsible for reviewing the NPDES Permit in its entirety,to ensure that all SWPPP measures are in place and permit requirements fulfilled throughout the durationof the project.SWPPP TRAINING (SECTION 21):SWPPP PREPARER:COMPANY: LARSON ENGINEERING, INC.CONTACT: GREG BUCHAL, 651-481-9120, GBUCHAL@LARSONENGR.COMCOURSE, INSTRUCTOR: DESIGN OF SWPPP, ONLINE COURSETRAINING ENTITY: UNIVERSITY OF MINNESOTAEXPIRATION: MAY 31, 2025SWPPP CONTACT:CONTRACTOR: (TBD)CONTACT: NAME, PHONE, EMAILCOURSE, INSTRUCTOR: TRAINING ENTITY:EXPIRATION:This SWPPP was prepared by personnel certified in design of construction SWPPP's as listed above. Copies ofrespective certifications are available upon request. In accordance with Section 21 of the permit, the followingindividuals must receive training, and the content and extent of the training is commensurate with the individual'sjob duties and responsibilities with regard to activities covered under the permit:a.Individuals preparing the SWPPP for the project.b.Individuals overseeing implementation of, revising and/or amending the SWPPP, and individualsperforming inspections for the project.c.Individuals performing or supervising the installation, maintenance and repair of BMP's.Individuals must receive training from local, state, federal agencies, professional organizations, or other entitieswith expertise in erosion prevention, sediment control, permanent stormwater treatment and the MNNPDES/SDS Construction Stormwater permit. Individuals shall attend a refresher-training course every three (3)years.SWPPP IMPLEMENTATION RESPONSIBILITIES:1.The Owner and Contractor are Permittee(s) as identified by the NPDES permit.2.The Contractor shall be responsible for all on-site implementation of the SWPPP, including allSubcontractor activities.3.The Contractor shall provide knowledgeable and experienced person(s) in the application, installation,and maintenance of Erosion and Sediment Control BMP's throughout the project.4.The Contractor shall provide person(s) meeting the training requirements of the NPDES permit to conductinspection and maintenance of all erosion prevention and sediment control BMP's in accordance withpermit requirements. One of these individuals must be available for an on-site inspection within 72 hoursupon request by the MPCA.5.The Contractor shall provide training documentation for all individual(s) required by the permit. Thistraining documentation shall be recorded in the SWPPP prior to construction, or as soon as personnel forthe project have been determined. Documentation shall include:a. Names of personnel associated with the project required to be trained (as listed above andunder Section 21 of the permit).b. Dates of training, name of instructor, and entity providing training.c. Content of training course or workshop including number of hours of training.INSPECTIONS AND MAINTENANCE:1.The Contractor shall provide person(s) meeting the training requirements to conduct inspection andmaintenance of all erosion prevention and sediment control BMP's under this project in accordance withpermit requirements.2.An example MPCA construction stormwater checklist can be found at the link below. Note: This templateinspection report does not address all aspects of the NPDES Permit. The completion of this checklistdoes not guarantee that all permit requirements are in compliance; it is the responsibility of thePermittee(s) to read and understand the full permit requirements.https://www.pca.state.mn.us/sites/default/files/wq-strm2-36.docxRECORDS RETENTION:The SWPPP, including all changes/amendments, and inspections and maintenance records shall be kept onsite during normal working hours by individuals who have operational control of that portion of the site.All Owner(s) shall keep the SWPPP, along with the following additional records, on file for three (3) years aftersubmittal of the NOT as outlined in Section 4:a.The Final SWPPP;b.Any other stormwater related permits required for the project;c.Records of all inspection and maintenance conducted during construction;d.All permanent operation and maintenance agreements that have been implemented, including allRight-Of-Way, Contracts, Covenants, and other binding requirements regarding perpetual maintenance;ande.All required calculations for design of the temporary and permanent stormwater management systems.PROJECT LOCATION AND RECEIVING WATERS MAP:SWPPPC001
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