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<br />EXISTING CONDITIONS
<br />C6,000 1 = 80
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<br />SPECIAL AND IMPAIRED WATERS
<br />THESE SPECIAL AND IMPAIRED WATERS ARE
<br />LOCATED WITHIN ONE MILE (AERIAL RADIUS) OF
<br />THE PROJECT LIMITS AND RECEIVE RUNOFF FROM
<br />THE PROJECT SITE. DUE TO THE PROXIMITY OF
<br />THESE SPECIAL ADN IMPAIRED WATERS, THE BMPS
<br />DESCRIBED IN APPENDIX A OF THE NPDES PERMIT
<br />WILL APPLY TO ALL AREAS OF THE SITE.
<br />WATERBODY
<br />IMPAIRMENT(S)
<br />FECAL CHLOROFORM;
<br />MISSISSIPPI RIVER
<br />FISHES BIOASSSESSMENTS;
<br />MERCURY IN FISH TISSUE
<br />MERCURY IN FISH TISSUE;
<br />LAKE ORONO
<br />NUTRIENT/EUTROPHICATION
<br />BIOLOGICAL INDICATORS
<br />MINIMUM ESTIMATED QUANTITIES FOR
<br />EROSION CONTROL
<br />ITEM DESCRIPTION
<br />ESTIMATED
<br />QUANTITY
<br />DRAINAGE STRUCT. INLET FILTER
<br />44
<br />EACH
<br />ROCK CONSTRUCTION ENTRANCE
<br />1
<br />EACH
<br />CONCRETE WASHOUT
<br />1
<br />EACH
<br />SILT FENCE
<br />2,111
<br />LF
<br />NOTE: QUANTITIES SHOWN ARE THE MINIMUM
<br />REQUIRED, ADDITIONAL QUANTITIES MAY BE NEEDED IF
<br />REQUIRED BY THE MPCA, WATERSHED DISTRICT, OR
<br />CITY. CONTRACTOR IS RESPONSIBLE FOR FINAL
<br />DETERMINATION OF QUANTITIES PRIOR TO
<br />CONSTRUCTION.
<br />EXISTING DRAINAGE AREAS
<br />DRAINAGE AREA
<br />IMPERVIOUS AREA
<br />(ACRES)
<br />PERVIOUS AREA
<br />(ACRES)
<br />TOTAL AREA
<br />(ACRES)
<br />Q OUT (CFS) STORM EVENT
<br />2-YEAR
<br />(2 85")
<br />10-YEAR
<br />(4.24")
<br />100-YEAR
<br />(6.96")
<br />ROUTING
<br />1
<br />10.85
<br />2.65
<br />13.50
<br />46.32
<br />71.48
<br />115.80
<br />SHEET FLOW SOUTH
<br />TOTAL
<br />10.85
<br />2.65
<br />13.50
<br />46.32
<br />71.48
<br />115.80
<br />PROPOSED
<br />DRAINAGE AREAS
<br />DRAINAGE AREA
<br />IMPERVIOUS AREA
<br />(ACRES)
<br />PERVIOUS AREA
<br />(ACRES)
<br />TOTAL AREA
<br />(ACRES)
<br />Q OUT (CFS) STORM EVENT
<br />2-YEAR
<br />(2 85")
<br />10-YEAR
<br />(4.24")
<br />100-YEAR
<br />(6.96")
<br />ROUTING
<br />1
<br />11.72
<br />1.77
<br />13.49
<br />49.89
<br />75.84
<br />120.30
<br />SHEET FLOW SOUTH
<br />TOTAL
<br />11.72
<br />1.77
<br />13.49
<br />49.89
<br />75.84
<br />120.30
<br />STORMWATER RUNOFF SUMMARY
<br />2-YR STORM (2.85")
<br />RUNOFF (CFS)
<br />10-YR STORM (4.24")
<br />RUNOFF (CFS)
<br />100-YR STORM (6.96")
<br />RUNOFF (CFS)
<br />EXISTING SITE
<br />46.32
<br />71.48
<br />115.80
<br />PROPOSED SITE
<br />49.89
<br />75.84
<br />120.30
<br />HANDLING AND STORAGE OF HAZARDOUS
<br />MATERIALS:
<br />IF THE CONTRACTOR INTENDS TO USE POLYMERS,
<br />FLOCCULANTS, OR OTHER SEDIMENTATION
<br />TREATMENT CHEMICALS ON THE PROJECT SITE, THE
<br />CONTRACTOR MUST COMPLY WITH THE FOLLOWING
<br />MINIMUM REQUIREMENTS:
<br />1. THE CONTRACTOR MUST USE CONVENTIONAL
<br />EROSION AND SEDIMENT CONTROLS PRIOR TO
<br />CHEMICAL ADDITION TO ENSURE EFFECTIVE
<br />TREATMENT. CHEMICALS MAY ONLY BE APPLIED
<br />WHERE TREATED STORMWATER IS DIRECTED TO
<br />A SEDIMENT CONTROL SYSTEM WHICH ALLOWS
<br />FOR FILTRATION OR SETTLEMENT OF THE FLOC
<br />PRIOR TO DISCHARGE.
<br />2. CHEMICALS MUST BE SELECTED THAT ARE
<br />APPROPRIATELY SUITED TO THE TYPES OF
<br />SOILS LIKELY TO BE EXPOSED DURING
<br />CONSTRUCTION, AND TO THE EXPECTED
<br />TURBIDITY, PH AND FLOW RATE OF
<br />STORMWATER FLOWING INTO THE CHEMICAL
<br />TREATMENT SYSTEM OR AREA.
<br />3. CHEMICALS MUST BE USED IN ACCORDANCE
<br />WITH ACCEPTED ENGINEERING PRACTICES, AND
<br />WITH DOSING SPECIFICATIONS AND SEDIMENT
<br />REMOVAL DESIGN SPECIFICATIONS PROVIDED BY
<br />THE MANUFACTURER OR PROVIDER/SUPPLIER
<br />OF THE APPLICABLE CHEMICALS.
<br />ON -SITE FUEL TANKS REQUIRE SECONDARY
<br />CONTAINMENT AS REQUIRED BY THE PERMIT.
<br />PORTABLE FUEL TRUCKS SHALL HAVE THEIR SPILL
<br />KITS AVAILABLE DURING FUELING. SPILLS GREATER
<br />THAN 5 GALLONS MUST BE REPORTED TO THE
<br />PROPER AUTHORITIES.
<br />GRADING & SOILS
<br />BASED ON SOIL BORING(S) PROVIDED BY AMERICAN
<br />ENGINEERING AND TESTING SOILS TYPICALLY FOUND
<br />ON THIS PROJECT ARE: SP-SM, FILL.
<br />REFER TO THE GEOTECHNICAL REPORT FOR
<br />ADDITIONAL INFORMATION.
<br />PROJECT NARRATIVE
<br />THE PROJECT SITE IS A PORTION OF THE ELK RIVER HIGH SCHOOL AND VANDENBERGE MIDDLE SCHOOL.
<br />CURRENTLY RUNOFF SHEET FLOWS SOUTH ACROSS THE SITE TO STORM SEWER IN SCHOOL STREET. ULTIMATELY
<br />STORMWATER RUNOFF GOES TO THE LIONS PARK STORMWATER POND.
<br />THE PROPOSED PROJECT CALLS FOR THE REMOVAL OF THE PAVEMENT AT ELK RIVER HIGH SCHOOL AND
<br />VANDENBERGE MIDDLE SCHOOL. ALSO THE VANDENBERGE MIDDLE SCHOOL STORMWATER POND WILL BE
<br />REMOVED. RUNOFF WILL CONTINUE TO SHEET FLOW SOUTH ACROSS THE SITE TO STORM SEWER IN SCHOOL
<br />STREET. ULTIMATELY STORMWATER RUNOFF FLOWS TO THE LIONS PARK STORMWATER POND FOR TREATMENT AND
<br />RATE CONTROL.
<br />CONSTRUCTION ACTIVITY EROSION
<br />PREVENTION PRACTICES
<br />CONTRACTOR SHALL STABILIZE ALL EXPOSED SOIL
<br />AREAS (INCLUDING STOCKPILES). STABILIZATION
<br />MUST BE INITIATED IMMEDIATELY TO LIMIT SOIL
<br />EROSION WHENEVER ANY CONSTRUCTION ACTIVITY
<br />HAS PERMANENTLY OR TEMPORARILY CEASED ON
<br />ANY PORTION OF THE SITE AND WILL NOT RESUME
<br />FOR A PERIOD EXCEEDING 7 CALENDAR DAYS.
<br />STABILIZATION MUST BE COMPLETED NO LATER
<br />THAN 7 CALENDAR DAYS AFTER THE CONSTRUCTION
<br />ACTIVITY IN THAT PORTION OF THE SITE HAS
<br />TEMPORARILY OR PERMANENTLY CEASED.
<br />FOR PUBLIC WATER THAT THE DNR HAS
<br />PROMULGATED "WORK IN WATER RESTRICTIONS"
<br />DURING SPECIFIED FISH SPAWNING TIME FRAMES,
<br />ALL EXPOSED SOIL AREAS THAT ARE WITHIN 200
<br />FEET OF THE WATER'S EDGE, AND DRAIN TO THESE
<br />WATERS MUST COMPLETE THE STABILIZATION
<br />ACTIVES WITHIN 24 HOURS DURING THE
<br />RESTRICTION PERIOD.
<br />PIPE OUTLETS MUST BE PROVIDED WITH
<br />TEMPORARY OR PERMANENT ENERGY DISSIPATION
<br />WITHIN 24-HOURS AFTER CONNECTION TO A
<br />SURFACE WATER.
<br />SEDIMENT CONTROL MEASURES MUST BE INSTALLED
<br />ON ALL DOWN GRADIENT PERIMETERS BEFORE ANY
<br />UPGRADIENT LAND DISTURBING ACTIVITIES BEGIN.
<br />SEDIMENT AND EROSION CONTROL
<br />MAINTENANCE
<br />PERIMETER SEDIMENT CONTROL PRACTICES: WHEN
<br />SEDIMENT REACHES 1/3 THE HEIGHT OF THE BMP,
<br />THE SEDIMENT MUST BE REMOVED WITHIN 24
<br />HOURS. IF PERIMETER SEDIMENT CONTROL HAS
<br />BEEN DAMAGED OR IS NOT FUNCTIONING
<br />PROPERLY, IT MUST BE REPAIRED AND/OR
<br />REPLACED WITHIN 24 HOURS. PERIMETER BMP
<br />MEASURES MAY INCLUDE SILT FENCING.
<br />CONSTRUCTION SITE VEHICLE EXIT LOCATIONS: ALL
<br />TRACKED SEDIMENT ONTO PAVED SURFACES MUST
<br />BE REMOVED WITHIN 24 HOURS OF DISCOVERY OR
<br />MORE FREQUENTLY IF REQUIRED BY CITY OR
<br />WATERSHED.
<br />CONSTRUCTION SITE DEWATERING:
<br />THE CONTRACTOR SHALL BE RESPONSIBLE FOR
<br />OBTAINING ALL DEWATERING PERMITS. DISCHARGE
<br />FROM ALL DEWATERING OPERATIONS SHALL BE
<br />DIRECTED TO ON -SITE DEPRESSIONS. NO
<br />DISCHARGE FROM DEWATERING OPERATIONS SHALL
<br />BE DIRECTED OFF -SITE TOWARDS A WATER OF THE
<br />STATE.
<br />PORTABLE TOILET NOTES:
<br />1. PORTABLE TOILETS POSE AN ENVIRONMENTAL
<br />HAZARD WHEN PLACED IN THE VICINITY OF
<br />STORM DRAINS OR BODIES OF WATER.
<br />PORTABLE TOILET CLEANING ACTIVITIES CAN
<br />ALSO GENERATE POLLUTANTS THAT CAN
<br />DEGRADE WATER QUALITY.
<br />2. PORTABLE TOILET PLACEMENT:
<br />2.1. PLACE PORTABLE TOILETS ON FLAT STABLE
<br />GROUND WITH CLEAR ACCESS TO THE
<br />UNITS.
<br />2.2. LOCATE TOILETS A MINIMUM OF 20 FEET
<br />FROM ANY WATER BODY AND 10 FEET
<br />FROM ANY CURB AND GUTTER. IF
<br />UNFEASIBLE, AN EARTHERN BERM OR SAND
<br />BAG BERM SHALL BE PLACED AROUND THE
<br />UNIT FOR SPILL AND LEAK CONTAINMENT.
<br />2.3. AVOID PLACING TOILETS ON IMPERVIOUS
<br />SURFACES THAT WILL QUICKLY DRAIN TO
<br />STORM SEWERS.
<br />2.4. LOCATE TOILETS SO THAT EXPOSURE TO
<br />TRAFFIC AND MOVING EQUIPMENT IS
<br />MINIMIZED.
<br />2.5. SECURE TOILETS TO THE GROUND WITH
<br />STAKES OR CABLES.
<br />2.6. RINSE WATER FROM CLEANING ACTIVITIES
<br />SHALL NOT BE DISPOSED ON SITE.
<br />3. REGULARLY CHECK TOILETS FOR DAMAGE,
<br />LEAKS AND SPILLS AS PART OF THE WEEKLY
<br />STORMWATER SITE INSPECTION.
<br />4. OWNER IDENTIFICATION AND CONTACT
<br />INFORMATION SHALL BE DISPLAYED IN A
<br />PROMINENT LOCATION ON EACH UNIT.
<br />1►1
<br />60' 30' 0 60' 120'
<br />SCALE 1W = 60'
<br />MECHANICAL AND NON STORMWATER
<br />DISCHARGES, EXISTING AND PROPOSED
<br />1. WATER LINE FLUSHING
<br />2. LANDSCAPE IRRIGATION
<br />3. DISCHARGE FROM POTABLE WATER SOURCES
<br />AGENCY CONTACTS
<br />CITY OF ELK RIVER
<br />ENGINEERING DEPARTMENT
<br />PHONE: (763) 635-1000
<br />MINNESOTA POLLUTION CONTROL AGENCY
<br />PHONE: (651) 296-6300
<br />INDEPENDENT SCHOOL DISTRICT 728
<br />11500 193RD AVENUE NW
<br />ELK RIVER, MN 55330
<br />PHONE: (763) 241 -3400
<br />NOTE:
<br />THE CONTRACTOR MUST COMPLETE, SIGN, OBTAIN
<br />OWNERS SIGNATURE, PAY FEE, AND SEND IN THE
<br />NPDES PERMIT APPLICATION. CONTRACTOR SHALL
<br />PROVIDE A CERTIFIED EROSION CONTROL
<br />SUPERVISOR. SWPPP DOCUMENTATION, INCLUDING
<br />INSPECTION REPORTS SHALL BE RETAINED FOR A
<br />PERIOD OF THREE (3) YEARS. DESIGN
<br />CALCULATIONS ARE ON FILE AT BKBM.
<br />THE OWNER AND CONTRACTOR ARE RESPONSIBLE
<br />FOR IMPLEMENTATION OF THE SWPPP AND
<br />INSTALLATION, INSPECTION, AND MAINTENANCE OF
<br />THE EROSION PREVENTION AND SEDIMENT CONTROL
<br />BMPS, BEFORE, DURING, AND AFTER CONSTRUCTION
<br />UNTIL THE NOTICE OF TERMINATION HAS BEEN
<br />FILED.
<br />STOCKPILES:
<br />ON -SITE STOCKPILES OF SOIL SHALL HAVE
<br />PERIMETER SEDIMENT CONTROL. STOCKPILES SHALL
<br />BE STABILIZED WITH BLANKETS, TARPS, OR HYDRO
<br />MULCH IF LEFT ON -SITE FOR MORE THAN 7 DAYS.
<br />TEMPORARY SEDIMENT BASINS:
<br />TEMPORARY SEDIMENT BASINS SHALL BE PROVIDED
<br />PER APPENDIX A, SECTION C.1.13 OF THE MPCA
<br />GENERAL STORMWATER PERMIT.
<br />ENGINEER ANTICIPATES THAT, PRIOR TO
<br />INSTALLATION OF FILTRATION MEDIA AND DRAIN TILE,
<br />CONTRACTOR WILL USE PROPOSED FILTRATION
<br />BASINS AS TEMPORARY SEDIMENT BASINS.
<br />CONTRACTOR SHALL EXCAVATE TEMPORARY BASINS
<br />AND CLAY LINE PRIOR TO USE. SURFACE WATER
<br />SHALL BE REMOVED BY SKIMMER DEVICE SUCH AS
<br />FAIRCLOTH SKIMMER OR THIRSTY DUCK, OR USING
<br />A PUMP WITH A FILTER. ALTERNATIVE TEMPORARY
<br />SEDIMENT BASINS SHALL BE APPROVED BY
<br />ENGINEER PRIOR TO USE.
<br />IN LIEU OF USING TEMPORARY SEDIMENT BASINS,
<br />THE CONTRACTOR MAY PHASE THEIR CONSTRUCTION
<br />SO THAT NOT MORE THAN 5 ACRES OF AREA IS
<br />DISTURBED AT ONE TIME. FULL STABILIZATION OF
<br />THE DISTURBED AREA IS REQUIRED PRIOR TO
<br />DISTURBING ADDITIONAL AREAS.
<br />SWPPP IMPLEMENTATION, INSTALLATION,
<br />INSPECTION, AND BMP MAINTENANCE BY
<br />NPDES PERMITING CONTRACTOR.
<br />NAM E:
<br />CERTIFICATION #:_____________
<br />DATE:
<br />OTHER NOTES:
<br />1. THIS SWPPP WAS PREPARED BY PERSONNEL
<br />THAT ARE CERTIFIED IN THE DESIGN OF
<br />CONSTRUCTION SWPPPS. COPIES OF THE
<br />CERTIFICATIONS ARE ON FILE WITH BKBM AND
<br />ARE AVAILABLE UPON REQUEST.
<br />2. THIS SWPPP DOCUMENT MUST BE AMENDED
<br />AS NECESSARY DURING CONSTRUCTION IN
<br />ORDER TO KEEP IT CURRENT WITH THE
<br />POLLUTANT CONTROL MEASURES UTILIZED AS
<br />THE SITE. THE SITE MAP SHOWING LOCATIONS
<br />OF ALL STORM WATER CONTROLS MUST BE
<br />POSTED ON THE SITE AND UPDATED TO
<br />REFLECT THE PROGRESS OF CONSTRUCTION.
<br />N OTE:
<br />THE STORM WATER POLLUTION PREVENTION PLAN
<br />FOR THIS PROJECT INCLUDES THE CIVIL
<br />ENGINEERING PLANS AND THE PROJECT MANUAL.
<br />CONTRACTOR TO SUPPLY CONSTRUCTION PHASING
<br />NARRATIVE, ESTIMATED PRELIMINARY QUANTITIES OF
<br />ALL EROSION PREVENTION AND SEDIMENT CONTROL
<br />BMP'S ANTICIPATED AT THE START OF THE
<br />PROJECT AND FOR THE LIFE OF THE PROJECT,
<br />AND LOCATION OF AREAS WHERE CONSTRUCTION
<br />WILL BE PHASED TO MINIMIZE DURATION OF
<br />EXPOSED SOIL AREAS. CONTRACTOR IS TO REVIEW
<br />MINNESOTA POLLUTION CONTROL AGENCY'S
<br />INSTRUCTIONS FOR THE APPLICATION FOR
<br />MINNESOTA'S NPDES/SDS GENERAL STORMWATER
<br />PERMIT FOR CONSTRUCTION ACTIVITY PRIOR TO
<br />SUBMITTING APPLICATION.
<br />INSPECTIONS
<br />EXPOSED SOIL AREAS: ONCE EVERY 7 DAYS AND
<br />WITHIN 24 HOURS FOLLOWING A 1/2 INCH OVER
<br />24 HOURS RAIN EVENT.
<br />STABILIZED AREAS: ONCE EVERY 30 DAYS.
<br />FROZEN GROUND: AS SOON AS RUNOFF OCCURS
<br />OR PRIOR TO RESUMING CONSTRUCTION.
<br />RECORDS: A COPY OF THE GRADING, DRAINAGE
<br />EROSION CONTROL PLAN AND WATERSHED DATA &
<br />SWPPP PLANS AS WELL AS THE
<br />INSPECTIONS/MAINTENANCE LOGS ARE TO BE KEPT
<br />EITHER IN THE FIELD OFFICE, INSPECTOR'S VEHICLE
<br />OR CONTRACTOR'S VEHICLE.
<br />2020 Elk River
<br />High School
<br />Parking Lot
<br />Improvements
<br />900 School St NW
<br />Elk River, MN 55330
<br />Independent School
<br />District #728
<br />11500 193rd Ave. NW
<br />Elk River, MN 55330
<br />WOLD ARCHITECTS
<br />AND ENGINEERS
<br />332 Minnesota Street, Suite W2000
<br />Saint Paul, MN 55101
<br />woldae.com 1 651 227 7773
<br />BKBM'
<br />ENGINEERS
<br />6120 Earle Brown Drive, Suite 700
<br />Minneapolis, MN 55430
<br />Phone: (763) 843-0420
<br />Fax: (763) 843-0421
<br />www.bkbm.com
<br />CONSTRUCTION
<br />DOCUMENTS
<br />O2020 BKBM Professional Engineers, Inc.
<br />All rights reserved.
<br />This document is an instrument of service and is the property of BKBM
<br />Professional Engineers, Inc. and may not be used or copied without
<br />prior written consent.
<br />BKBM JOB NUMBER: 17445.01
<br />I hereby certify that this plan, specification or report was
<br />prepared by me or under my direct supervision and that I am
<br />a duly Licensed Professional Engineer under the laws of the
<br />State of Minnesota.
<br />Kevin A. Bohl
<br />License Number: 52209 Date 01/03/2020
<br />Revisions
<br />Date
<br />Comm: 182030
<br />Date: 01 /03/2020
<br />Drawn: WH (I
<br />Check: KAB North
<br />STORM WATER
<br />POLLUTION
<br />PREVENTION PLAN
<br />6mOOO
<br />VICINITY MAP
<br />
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