8.0-10.0 Waterview SWPP Plan - SBI Responses 080824STORM SEWER POLLUTION PREVENTION PLAN (SWPPP)
WATERY IEW
1. CONSTRUCTION ACTIVITY INFORMATION
This SWPPP was prepared by personnel certified in the design of construction SWPPPs. Copies of certifications
are available upon request. (Sathre-Bergquist, Inc. - Michael VanGuilder- 952-476-6000)
Project Name: Waterview
Project Location:
Address : 6670 Minnewashta Pkwy
City: Chanhassen State: Minnesota Zip Code : 55331
County Parcel ID Number (PID): 250053100
Project Type: R i nti I ram r i I Industrial Road Construction
Residential/Road Construction Other
Cumulative Impervious Surface
Number of acres to be disturbed:
2.3 (tenths of an acre)
Pre -construction acres of impervious surface:
0.4 (tenths of an acre)
Post -construction acres of impervious surface:
0.8 (tenths of an acre)
Total new impervious surface acres:
0.8 (tenths of an acre)
Receiving Waters
Name of Water Body Type Special
Water? Impaired? Water?
Lake Minnewashta Lake
No
Yes
Lake Virginia Lake
No
Yes
Tamarack Lake Lake
No
No
Lake Minnetonka Lake
No
No
Dates of Construction
Construction Start Date: 08/01/2024
Estimated Completion Date: 11/30/2024
2. General Construction Project Information
Personnel & Training
Certified erosion control supervisor in good standing with who is knowledgeable & experienced in the application of erosion
prevention & sediment control BMPs. (CONTRACTOR - CONTACT- PHONE #)
Supervisor shall work with the project engineer/City of Chanhassen to oversee implementation of the SWPPP & the
installation, inspection & maintenance of the erosion control BMPs.
Long term O&M of permanent stormwater treatment systems - (City of Chanhassen)
Chain or Responsibility
Owner / Developer & Contractor are copermitees for the National Pollutant Discharge Elemination System (NPDES)
Construction Permit. Contractor is responsible to comply with all aspects of hte NPDES Construction Permit at all times
until the Notice of Termination (NOT) has been filed with the MPCA or transferred to home builder or another contractor.
Contractor will develop a chain of command with all operators on the site to ensure that the SWPPP will be implemented &
stay in effect until construction is complete, the site has final stabilization & NOT has been submitted to the MPCA
Describe the construction activity
This +/- 3.0 acre development will consist of the land development of 5 single family detached homes, and 100 linear feet of
streets. Other soil disturbing activites will include: home building, driveway construction, and lot landscaping. This project
will be mass graded and constructed in 1 phase , grading will be completed in Fall 2024, and utilities completed in 2024.
Soil disturbing activities will include: Demolition of the existing structures, installation of a rock entrance berm, clearing and
grubbing, installation of utilities/minor utilities(including private utilities-gas,cable,electric, etc..), the installation of silt fence
and tree fence prior to grading, the installation of silt fence around the proposed ponding areas after the grading is
complete, grading, re -spreading topsoil, and grading restoration which will consist of seeding and mulching all disturbed
areas outside of the street row. Erosion blanket will also be installed on all 3:1 slopes or greater. Additional erosion blanket
may be used throughout the site. See the Erosion & Sediment Control Plan for specific locations.
3. SWPPP Amendments
4. Temporary Erosion Prevention Practices
Describe types of erosion prevention BMPs expected to be implemented
Perimeter Control shall be established around the site & around the base of stockpiles if the stockpile will remain longer than 30 days. Perimeter control is typically established with silt
fence which also deliniates areas not to be disturbed. Silt Fence locations are shown on the Grading & Erosion Control plans. Where possible 50ft buffers shall be maintained around
surface waters & wetland. Dual perimeter controls shall be installed if work is to take place within 5Dft of surface waters & wetlands.
Erosion blanket will be installed on all 3:1 slopes.
During construction
a. Stabilization of all exposed areas must be initiated immediately to limit soil erosion but in no case laterthan seven (7) days afterthe construction activity in that portion of the site has
temporarily or permanently ceased.
Once grading is complete, temporary erosion BMPs shall be installed immediately (is. bio-rolls, erosion blanket, ditch checks, etc). No later than seven (7) days, the permanent
stabilization should be in place.
b. Temporary sediment basin requirements described in Part III.B.1-5 must be used for common drainage locations that serve an area with five (5) or more acres disturbed at one time.
This project is being constructed in 1 phase. The permanent dry sediment basins shall be constructed first and all on -site drainage shall be routed to the ponds. The site does not have
any concentrated swales that will directly discharge off -site
List anticipated BMP Quantities
• Silt Fence (Before Construction) - 1,930 LF
• Silt Fence (After Construction) - 370 LF
• Erosion Blanket- as needed
Methods of dissipating velocity along stormwater conveyance channels/ outlets
• Rip -rap will be used at all flared -end structures
Check Dams - Installation of check dams or other grade control practice to ensure sheet flow and prevent rills (for slopes greater than 75 feet with a grade of 3:1 or steeper)
Methods to be used for stabilization of ditch and Swale wetted perimeters
Bio-rolls shall be used for stabilization of ditches and swales as shown on the Erosion Control Plan.
Methods to be used for energy dissipation at pipe outlets
• Rip -rap will be used at flared -end structures for energy dissipation. See plan for quantities.
Methods to be used to promote infiltration and sediment removal on the site prior to discharge
• The water quality volume that must be treated by the project's permanent stormwater management system described in Part III.C. shall be 1/2 inch of runoff from the new impervious
surfaces created by the project. See Part III.C.2 for more information on infiltration design and appropriate site conditions. If it is determined that site conditions are not appropriate
for infiltration (e.g. lack of 3 ft. of separation to seasonally saturated ground water, proximity to bedrock, contaminated soils) the reasons should be documented in the Stormwater
Pollution Prevention Plan (SWPPP) for the project. Infiltration is not required in Hydrologic Soil Group D soils. Clay soils throughout the site resulted in volume reduction being
achieved via filtration shelf's in three (3) of the onsite ponds.
Timelines to be implemented on site for completing the installation of the erosion prevention BMPs
• Prior to Grading - Silt and tree fence to locate grading limits and provide down gradient sediment control. Rock Entrance Berm to be installed.
Home building BMPs
Single family lots within the overall site will be disturbed on a lot by lot basis as lots are sold & homes are constructed. Home construction shall disturb
previously stabilized areas. Typically entire lots will be disturbed as finish grading is completed. Areas not to be disturbed are typically designated by the use
of silt fence. Topsoil shall be preserved by stockpiling with sediment control installed around the perimeter of the stockpile. Individual lots under construction
shall also install vehicle tracking measures such as rock entrance berm or other tracking control BMP to maintain clean streets. Home builders shall be
responsible for erosion & sediment control installation, maintenance, SWPPP inspection and record keeping for lots under their construction.
Home Construction BMP Phasing
Protect lot area through use of one or a combination of the following; silt fence, mulch, bio-rolls, rock entrance berm, sod buffers or other
approved method. In areas within 50ft of surface waters redundant controls shall be installed if a 50ft buffer can not be maintained.
install drainage protection on down gradient inlets.
Establish staging / material storage area & Install temporary sanitary Facilities& supply dumpsters
Prevent & manage spills of stored substances
Install Rock entrance berm, maintain clean streets
Home Construction
Manage & protect stockpiles
maintain rock entrance berm & perimeter controls
trench, install & connect utilities
Continue vertical construction
Keep streets clean at all times & maintain inlet protecton
Fine grad pads, Upon completion of fine grade pads & home construction soils disturbing activities, each lot shall be stabilized with sod, seed,
mulch, hydromulch, hydroseed, straw matting or combination there of. Monitor stabilized areas until final stabilization is achieved
Maintain clean streets
Perimeter & temporary erosion & sediment controls are to remain in place until all up gradient areas have been permanently stabilized.
Post Construction
Remove silt fence after once final vegetation stabilization is established
Remove inlet protection
Remove all construction materials & debris from site
clean all drainage structures
Remove all temporary erosion & sediment control BMPs & stabilize areas left disturbed.
File NOT for individual lot
6. Permanent Stormwater Management System
Will the project result in one acre or more of new impervious area? -YES
Grading - Erosion blanket will be utilized on all 3:1 slopes. Biorolls will be used in rear yard swales. MnDot seed mix #250 will be spread at a rate of 100 lbs./acre and fertilize with If Yes,
20-0-10 at 100 lbs./acre. Only phosphorus free fertilizer shall be used. Where a project's ultimate development replaces vegetation and/or other pervious surfaces with one (1) or more acres of cumulative impervious surface, the
Permittee(s) must design the project so that the water quality volume of one (1) inch of runoff from the new impervious surfaces created by the project is
Utility & Street Work - Inlet protection on all storm sewer catchbasins. Weekly street sweeping to prevent off -site vehicle tracking. However weekly sweeping may not be adequate. retained on site (Le. infiltration or other volume reduction practices) and not discharged to a surface water. For purposes of this part, surface waters does not
Sweeping is required 24 hours after discovery of track out. include manmade drainage systems that convey stormwater to a compliant permanent stormwater management system.
Permanent BMPs - Sediment bays are to be installed at flared end sections draining into dry pond and infiltration areas. Rip -rap to provide provide energy dissipation and prevent
erosion.
Additional Erosion Control Prevention Measures to be Implemented on Site
• Erosion Blanket- This blanket will be installed as indicated on the erosion and sediment control plan. It will provide slope protection until the turf is established. For retaining wall
construction the grading contractor will install Erosion blanket on the temporary 1:1 slopes until the wall construction can be completed.
• Bio-rolls - Bio-rolls will be installed in swale areas to help slow runoff and minimize erosion.
• Seeding Restoration - Temporary/Permanent Stabilization (Seeding and Mulching) - Temporary seeding and mulch must be placed on all disturbed soil within 14 days, unless
actively being worked on. All disturbed areas will be restored with 4" to 6" of topsoil. The restoration shall begin within 72 hours of the grading completion. The seed mix shall be
MNDot Mix No. 250 applied at a rate of 100 Ibs/acre and fertilized with 20-0-10 at a rate of 100 lbs. per acre. The mulch shall be Type 1 and applied at a rate of 2 tons per acre, disc
anchored (with disc blades set nearly straight) immediately after placement.
• Sodding - Two types of sodding will be done with this project. The first will be for erosion control protection for the streets, after the installation of the curb and the minor utilities the
contractor will install two rows of sod behind the curb for a temporary erosion protection. The second type of sod will be for the yards once the house construction is complete.
5. Temporary Sediment Control Practices
Methods of sediment control BMPs to be implemented on site
• Sediment controls for temporary or permanent drainage ditches and sediment basins that are designed as part of a treatment system
• Installation of check dams or other grade control practice to ensure sheet flow and prevent rills (for slope lengths greater than 75 feet with a grade of 3:1 or steeper).
• Sediment control practices on all down gradient perimeters prior to land disturbing activities.
• Storm drain inlet protection for all inlets.
• Silt fencing or other sediment control surrounding temporary soil stockpiles.
• Minimize vehicle tracking of sediments (e.g., stone pads, concrete or steel wash racks, or equivalent systems).
• Street sweeping of tracked sediment
A copy of the Stormwaer Management Report is available through the owner or engineer upon request.
Soil data and water level map is included in the Stormwater Management Report.
Methods to be used for down gradient perimeter control
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The SWPPP must be amended as necessaryto include additional requirements, such as additional or modified BMPs that
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• Silt Fences- are designed as a temporary sediment barrier consisting of a filter fabric attached to support posts. This site has three applications for silt fence. These applications arely
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are designed to correct problems identified or address situations whenever:
as follow: 1. the installation of silt fence along the grading limits to protect the wetlands from sediment during the grading and utility construction process, 2. the installation of silt
fence around the created ponds and rain gardens after construction to control the sediment runoff until the turf is established and the development is completed, 3. the installation of
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There is a change in design, construction, operation, maintenance, weather or seasonal conditions that has a
silt fence surrounding temporary stockpiles.
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significant effect on the discharge of pollutants to surface waters or underground waters.
If down gradient BMPs are overloaded (based on frequent failure or excessive maintenance), additional up gradient BMPs shall be installed to eliminate the overloading. The inspector or
2. Inspections or investigations by site owner or operators, USEPA or MPCA officials indicate the SWPPP is not
contractor shall notify the design engineer to establish appropiate up gradient BMP's or elimate any point load sources.
effective in eliminating or significantly minimizing the discharge of pollutants to surface waters or underground
waters or that the discharges are causing water quality standard exceedances (e.g., nuisance conditions as
Methods to be used to contain Stockpiles
defined in Minn. R. 7050.0210, subp. 2).
Silt fence- will be used to provide perimeter control around stockpiles.
3. The SWPPP is not achieving the general objectives of minimizing pollutants in storrnwater discharges associated
Methods to be sued for storm drain inlet protection
with construction activity, or the SWPPP is not consistent with the terms and conditions of this permit.
• Storm Drain Inlet Protection - Storm drain inlet protection is a sediment barrier placed around a storm sewer inlet. This structure traps sediment before it enters the storm sewer
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4. At any time after permit coverage is effective, the MPCA may determine that the project's stormwater
system. The utility contractor will be required to install inlet protection per the City's details.
discharges may cause, have reasonable potential to cause, or contribute to non -attainment of any applicable
. Outlet Structures and Outlet Protection - There are wetlands located within & adjacent to this project, as a result outlet structures are proposed to transfer water from the storm water
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water quality standard, or that the SWPPP does not incorporate the applicable requirements in Part I I I.A.8.,
treatment pond to the wetland after treatment. These structures will serve to provide skimming and rate control. Rip -rap will be placed at the base of all aprons to provide erosion
(Impaired Waters and TM DLs). If a water quality standard changes during the term of this permit, the MPCA will
protection by protecting the downstream soils from turbulence and high discharge velocities.
make a determination as to whether a modification of the SWPPP is necessary to address the new standard. If
the MPCA makes such determinatiorl or any of the determinations in Parts 111.B.1: 3., the MPCA will notify the
Methods to minimize vehicle tracking at construction exits and street sweeping activites
Pennittee(s) in writing. In response, the Pennittee(s) must amend the SWPPP to address the identified concerns
• Temporary Rock Construction Entrance - A rock entrance berm is constructed of coarse clean rock installed at the proposed entrance point for all construction vehicles. A detail of
and submit information requested by the MPCA, which may include an individual permit application. If the
the rock entrance berm is shown on the final grading plan. This stone pad provides a tire cleaning mechanism for all vehicles leaving the site. There is one entrance forthis project.
MPCA's written notification requires a response, failure to respond within the specified timeframe constitutes a
Please see the Erosion & Sediment Control Plan for location of rock entrance berth.
permit violation.
• Street Sweeping - Weekly street sweeping shall be taken place. However weekly sweeping may not be adequate. Sweeping is required 24 hours after discovery of track out.
Methods to be used to minimize soil compaction and preserve top soil (unless infeasible) on site
• '„
• Topsoil will be stripped and stockpiled. Grading operations will be performed and held down 0.5'to allow for topsoil respread.
EXISTING UTILITIES SHOWN ARE SHOWN IN AN APPROXIMATE WAY ONLY. THE CONTRACTOR SHALL DETERMINE THE EXACT
Measures to be used if Dewaterinq is required on site
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LOCATION OF ANY AND ALL EXISTING UTILITIES BEFORE COMMENCING WORK. HEAGREESTOBEFULLYRESPONSIBLEFORANY
AND ALL DAMAGES ARISING OUT OF HIS FAILURE TO EXACTLY LOCATE AND PRESERVE ANY AND ALL EXISTING UTILITIES.
Dewaterin shall be routed to the sedimentation ponds for treatment before leaving site. See Erosion Control Plan for direction on Dewaterin methods
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DRAWING NAME
NO.
BY
DATE
REVISION
USE (INCLUDING COPYING, DISTRIBUTION, AND/OR CONVEYANCE OF
INFORMATION) OF THIS PRODUCT IS STRICTLY PROHIBITED WITHOUT
SATHRE-BERGQUIST, INC.'s EXPRESS WRITTEN AUTHORIZATION. USE WITHOUT
SAID AUTHORIZATION CONSTITUTES AN ILLEGITIMATE USE AND SHALL THEREBY
INDEMNIFY SATHRE-BERGQUIST, INC. OF ALL RESPONSIBILITY.
SATHRE-BERGQUIST, INC. RESERVES THE RIGHT TO HOLD ANY ILLEGITIMATE
USER OR PARTY LEGALLY RESPONSIBLE FOR DAMAGES OR LOSSES RESULTING
FROM ILLEGITMATE USE.
I HEREBY CERTIFY THAT THIS PLAN OR SPECIFICATION WAS
PREPARED BY ME OR UNDER MY DIRECT SUPERVISION AND THAT I
AM A DULY REGISTERED PROFESSIONAL ENGINEER UNDER THE
LAWS OF THE STATE OFMINNESOTA.
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SATHRE-BERGQUIST, INC.
1400025THAVE N#120PLYMOUTH,MN.55447(952)47G6000
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CITY PROJECT NO.
CHANHASSEN, WATERVI EW
M I N N E SOTA
WOODDALE BUILDERS
FILE NO.
9745-166
WATERVIEW
1
RSM
07/09/24
City Comments - 6/28/24
DRAWN
2
RSM
07/10/24
Lot Width Adjustments
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RSM
DATE
ROBERTS. MOLSTAD, P.E.
Date: 06/14/24 Z�,t-/Z8
Lic. Na.
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