1. Storm Water Pollution Prevention Plan Development
Todd E. Hubmer PE WSB & Associates

2. 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

3. SWPPP Components
Ponding must treat 0.5” of runoff from new impervious surface for entire subwatershed
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
The handout is included on the course guide disk, entitled, “NPDES Phase II Construction Permit Info.doc”
This handout should be updated to reflect the most current requirements for the NPDES Phase II permit.
We also prepared a copy of the current NPDES Phase II permit, and distributed it as part of the course notes. That permit can be downloaded in its most up-to-date version.

4. Inspections and Maintenance
NPDES 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

5. Inspections and Maintenance
Inspection and maintenance must be recorded in writing and include:
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

6. Penalties/Enforcement
PCA will be increasing enforcement
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 Jail

7. Erosion Control BMP’s Required by NPDES

8. INLET PROTECTION

9. MAINTENANCE OF SILT FENCE
OR IF ADDITIONAL BMP’S
MAY BE REQUIRED
GEOTEXTILE FABRIC

10. ROCK CONSTRUCTION ENTRANCE TO REDUCE SEDIMENT TRACKED OFF SITE

11. FINAL STABILIZATION

12. DESIGNATED WASH-OUT SITE

13. CATEGORY 1 BLANKET, TEMPORARY SEED, AND SILT FENCE MAINTENANCE
AFTER
CATEGORY 1 BLANKET, TEMPORARY
SEED, AND SILT FENCE MAINTENANCE

14. Sediment tracked off site or on streets must be removed with 24 hours

15. Silt fence repaired, replaced when down or sediment reaches 1/3 height of fence w/i 24 hours

16. Other NPDES requirements
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

17. Other NPDES requirements
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

18. Other inspection requirements
Seeding timeline w/i 200 feet of surface water
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

19. Questions?