Transcript Slide 1

Storm Water Pollution
Prevention Plan Development
Todd E. Hubmer PE
WSB & Associates
[email protected]
How to develop a SWPPP
 Description
of the project
 Description of how storm water and
erosion will be manage on-site
 Includes narrative, erosion control plan
sheets, standard details
 Drainage map, soils map, ponding calcs
SWPPP Components
 Ponding
must treat 0.5” of runoff from new
impervious surface for entire
subwatershed
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Wet basin,
Regional pond,
Combination, or
Alternative method (rain garden, etc.; requires
90 day review by MPCA)
 Road
projects: fit in ponding if you can. If
cannot fit in, other options (grassy swales,
rock checks grit chambers, etc.) should be
used
Inspections and Maintenance
 NPDES
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requires inspection
Every 7 days
Within 24 hours of a 0.5 inch-24 hour rainfall
event
Once a month for areas that have undergone
final stabilization (but work is ongoing in other
areas)
See PCA calendar
Inspections and Maintenance
 Inspection
and maintenance must be
recorded in writing and include:
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Date and time
Name of inspector
Findings and recommendations
Corrective actions taken
Date and amount of rainfall >0.5” in 24 hrs
Documentation of changes in SWPPP
Penalties/Enforcement
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PCA will be increasing
enforcement
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SWCD’s, Watershed Districts can be
authorized agents for PCA
You will need to produce the
SWPPP and inspection reports
 Penalty for non-conformance is
$10,000 per day per violation
Erosion Control BMP’s
Required by NPDES
INLET PROTECTION
MAINTENANCE OF SILT FENCE
OR
IF
ADDITIONAL
BMP’S
GEOTEXTILE FABRIC
MAY BE REQUIRED
ROCK CONSTRUCTION ENTRANCE
TO REDUCE SEDIMENT TRACKED OFF SITE
FINAL STABILIZATION
DESIGNATED WASH-OUT SITE
AFTER
CATEGORY 1 BLANKET, TEMPORARY
SEED, AND SILT FENCE MAINTENANCE
Sediment tracked off site or on streets must
be removed with 24 hours
Silt
fence
repaired,
replaced when
down or sediment
reaches 1/3
height of fence
w/i 24 hours
Other NPDES requirements
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Silt fence repaired, replaced when down or sed
reaches 1/3 height of fence w/i 24 hours
 Temp and perm basins must be drained and
cleaned out when ½ storage volume is gone w/i
72 hours
 Sed deltas, filled CB’s, filled ditches must be
cleaned/stabilized w/i 7 days
 Sed tracked off site must be removed with 24
hours
Other NPDES requirements
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If sed in lakes, wetlands, streams, stabilize area
upstream and remove sed w/i 7 days
Hazardous materials stored appropriately
No dumping of oil, junk, etc
Garbage must be disposed of properly
Once site has undergone final stabilization, NOT
submitted
Other inspection requirements
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Seeding timeline w/i 200 feet of surface water
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Slope steeper than 3:1 – 7 days
Slope 10:1 to 3:1 – 14 days
Slope flatter than 10:1 – 21 days
Surface water is stream, lake, wetland, ditches,
ponds, whether natural or artificial.
 Stockpiles need silt fence
 Riprap at pipe ends w/i 24 hours of connecting
 Dewatering – Water must be directed to storm
water pond or treated before discharge
Questions?