Description of new 2009 California Stormwater Permit requirements

1. California stormwater permit requirements Michael Josselyn, PhD PWS WRA, Inc. November 2009

2. Purpose of presentation How is stormwater regulated in California?

3. Purpose of presentation How is stormwater regulated in California? What require-ments have been set by state government?

4. Purpose of presentation How is stormwater regulated in California? What require-ments have been set by state government? How are these regulations implemented?

5. Water quality regulations

6. Federal: Clean Water Act Enacted in 1972 to protect nation’s water quality Act prohibits the discharge of pollutants from a point source into “waters of the United States” Unless a permit is obtained by the discharger Environmental Protection Agency is given power to issue and enforce regulations Permit program has been delegated to the State of California—NPDES permits States also given power to approve wetland fill

7. stormwater regulations

8. Legal actions modify CWA Congress issues Clean Water Act 1972 EPA decides not to regulate stormwater due to problems inherent in regulating many outfalls Environmental organizations win law suits to have stormwater regulated under NPDES Congress amends Clean Water Act 1987 Industrial stormwater discharges regulated EPA considers construction activities to be industrial actions 1990 EPA mandated that construction activities be regulated under NPDES permits

9. State of California State Water Resources Control Board is responsible for overall water management in the state Defines stormwater as a “pollutant” and as a “point source” Subject to permitting under NPDES regulations One source of stormwater is from construction sites September 2009: New regulations for construction activities

10. Regional Authority State divided into regions based on watershed boundaries Each region responsible for separate “basin plans” Regulate water quality to ensure beneficial uses of the streams and lakes in its region

11. California construction General Stormwater Permit Established by State Water Resources Control Board September 2, 2009

12. Why focus on construction sites? 20 to 1000 times more sediment from construction sites Turbidity increases Nutrient input higher Sediment buildup in storm drainage devices

13. General permit: construction sites Covers earth moving activities > 4000 sq m Regulates the amount of sediment that can be discharged from construction sites Sets standards for the discharge of certain pollutants Turbidity and pH Establishes a “design storm criteria” Sets forth requirements related to risk level Requires submission of Storm Water Quality Pollution Prevention Plan (SWPPP)

14. Establishes Risk Levels Increasing level of protection Sediment Risk = Type of activity and location of activity Receiving Water Risk = “Sediment sensitivity” of water body

15. Establishes Risk Levels Increasing level of protection Sediment Risk = Type of activity and location of activity Receiving Water Risk = “Sediment sensitivity” of water body

16. Establishes Risk Levels Increasing level of protection Sediment Risk = Type of activity and location of activity Receiving Water Risk = “Sediment sensitivity” of water body

17. Sediment risk Based on soil erosion factor Calculated using Revised Universal Soil Loss Equation (RUSLE) Considers Rainfall Soil Erodibility Length-slope factor Cover factor Sediment controls

18. Revised universal soil loss equation A = R * K * LS * C * P A = the rate of sheet and rill erosion

19. Revised universal soil loss equation A = R * K * LS * C * P A = the rate of sheet and rill erosion R = rainfall-runoff erosivityfactor

20. Revised universal soil loss equation A = R * K * LS * C * P A = the rate of sheet and rill erosion R = rainfall-runoff erosivity factor K = soil erodibility factor LS = length-slope factor K/ LS Factor map for California

21. Revised universal soil loss equation A = R * K * LS * C * P A = the rate of sheet and rill erosion R = rainfall-runoff erosivity factor K = soil erodibility factor LS = length-slope factor C = Cover Factor P = Protection Measures employed

22. Revised universal soil loss equation A = R * K * LS A = the rate of sheet and rill erosion R = rainfall-runoff erosivity factor K = soil erodibility factor LS = length-slope factor C = Cover Factor = 1 for risk assessment P = Protection Measures employed = 1

23. Sediment loss risk factors Determine Value of A and relate risk below

24. Receiving water risk Most sensitivity to sedimentation Fish spawning areas Fish migration areas Any impaired water body for sediment

25. High RiSK = More controls Use Standard Construction BMPs Silt fences, hay bales, temporary detention Additional Factors to be added Ensure soil loss during each phase does not exceed preconstruction soil loss More frequent inspections Develop Rain Event Action Plans to prepare site within 48 hours in advance of rain events Must meet numeric standards for Turbidity and pH Establishes both action and limitation values

26. NUMERIC LIMITS Turbidity Action level = 250 NTU Limit level = 500 NTU Exceed Action Levels Improve BMPs and implement corrective actions Exceed Limit Levels Additional monitoring and possible fines pH Action level = 6.5-8.5 Limit level = 6.0 – 9.0

27. Turbidity measurement

29. Must submit stormwater plan:SWPPP Must be prepared by a qualified individual Evaluates Risk Factors Describes all the best management practices Describes compliance plan Provides for monitor- ing and reporting

31. Watershed regulations Wetland and Stream Protection

32. Water quality regulations

33. Wetland and stream fill protections 401 Water Quality Certification

34. Wetland and stream fill protections 401 Water Quality Certification Must approve loss of wetlands and streams in watersheds regulated by federal government Must try to avoid and minimize impacts Fill must be accompanied by wetland and stream replacement Usually 2 to 3 times as much land as filled

35. Wetland and stream fill protections 401 Water Quality Certification Porter Cologne Act Must approve loss of wetlands and streams in watersheds regulated by federal government Must try to avoid and minimize impacts Fill must be accompanied by wetland and stream replacement Usually 2 to 3 times as much land as filled

36. Wetland and stream fill protections 401 Water Quality Certification Porter Cologne Act Must approve loss of wetlands and streams in watersheds regulated by federal government Must try to avoid and minimize impacts Fill must be accompanied by wetland and stream replacement Usually 2 to 3 times as much land as filled Regulates fill placement in wetlands and streams Cannot result in decreased beneficial uses Fish habitat Human use and health Water quality

37. Watershed level regulation No net loss of wetland and stream habitat Requires that any loss be “mitigated” Replacement areas must be in same watershed

38. Mitigation policies Must create new wetlands and streams in greater quantity than lost—”Mitigation Ratio” Wetlands and stream creation must maintain or reduce hydromodification Wetland must be created similar to that which is lost Performance standards must be met over 5 year monitoring program

39. Wetland mitigation areas Freshwater marsh Riparian and Meadow Habitat

40. Also applies to tidal areas Batiquitos Lagoon Channel Construction

41. Wetland creation technology Has expanded significantly over past 20 years Many wetland types Freshwater marsh Riparian habitat Vernal pools Streams New policies in effect to improve science and performance

42. Mitigation banks Established by private companies Determine areas where development is occurring Create wetland and stream habitat May include habitat for unique plants and animals Sell credits on the open market to private parties and governmental agencies Must maintain these areas in perpetuity

43. Summary of state regulations Strictly regulates construction activities Sets methods to evaluate risk levels associated with various activities Establishes numeric standards for some attributes Seeks to control hydromodification Incorporate features in project design to control flow Regulates stream and wetland fill Requires habitat replacement through mitigation Sets standards for reporting and monitoring