Water Treatment Plant General Discharge Permit

1. Water Treatment Plant General Discharge Permit Kelli D. Buscher, P.E. SD DENR

2. Clean Water Act Background • 1972 - Clean Water Act established the National Pollutant Discharge Elimination System (NPDES) Program

3. Clean Water Act Background • All “Point Sources” • “discharging pollutants” • into “waters of the US” • must obtain a discharge permit

4. Clean Water Act Background • A discharge permit is required to use public resources for waste disposal and limits the amount of pollutants that may be discharged • The discharge of pollutants to waters is a privilege, not a right

5. Clean Water Act Background • All “waters of the state” have water quality standards • A water quality standard defines the water quality goal of a water body by designating the beneficial use or uses of the water body and by setting criteria necessary to protect those uses

6. Beneficial Uses (1) Domestic Water Supply Waters; (2) Coldwater Permanent Fish Life Propagation; (3) Coldwater Marginal Fish Life Propagation; (4) Warmwater Permanent Fish Life Propagation; (5) Warmwater Semipermanent Fish Life Propagation; (6) Warmwater Marginal Fish Life Propagation;

7. Beneficial Uses (7) Immersion Recreation Waters; (8) Limited Contact Recreation Waters; (9) Fish and Wildlife Propagation, Recreation, and Stock Watering Waters; (10) Irrigation waters; and (11) Commerce and Industry Waters.

8. What Needs to be Covered? • Treatment system overflows • Filter Backwash and Settling Basins • Disinfection and Flushing of Water Lines • Storage system disinfection and overflows • Water line breaks • Other WTP Discharges that fit the limits and management practices

9. Why a General Permit? • Ensure all discharges from water treatment systems are covered • Establish uniform criteria for discharges from these activities • Reduce the administrative time for permit authorization

10. What is NOT Covered? • If the discharge contains radioactive components • If the discharge is to a lake or POTW • If the discharge is a significant contributor of pollution • If the discharge presents a health hazard • If the discharge is not in compliance

11. What is NOT Covered? • If EPA develops federal limits for water treatment plant discharges • If a water quality management plan containing requirements applicable to the discharges is approved • If conditions or standards have changed so that the discharge no longer qualifies for the general permit.

12. Prohibitions • No discharge of sanitary wastewater • No direct discharge of solids and/or sludges • No discharge of floating solids or visible foam • No discharge of toxic pollutants in toxic amounts • SDDENR must be notified in advance of all chemicals used • Prevent or minimize stream scouring or bank erosion caused by the discharge

13. Limits • pH • 6.5-9.0 for most discharges • 6.5-8.8 for coldwater marginal fisheries • 6.6-8.6 for coldwater permanent fisheries

14. Limits • Total Suspended Solids • 90 mg/L for most • 30 mg/L for coldwater permanent fisheries • Total Dissolved Solids • 2,500 mg/L for most • 1,000 mg/L for domestic water supplies

15. Limits • Conductivity • 2,500 μmhos/cm • Chlorinated water • 0.05 mg/L Total Residual Chlorine • Chloraminated water • 0.05 mg/L Total Residual Chlorine • 1.0 mg/L Ammonia

16. Outfalls • DW1 • Raw or partially treated water from the treatment system • Lime softening ponds • Filter backwash • Overflows from treatment units • Raw water

17. Outfalls • DW2 • Completely treated water from treatment, storage, or distribution • Storage system overflows • Water line breaks • Hydrant flushing • Hydrostatic testing • Disinfection of new lines

18. Outfall DW1 Flow Duration of Discharge pH Temperature Total Fluoride Sulfates TSS TDS TRC (if chlorinating) Ammonia (if chloraminating) Conductivity Alkalinity Monitoring Requirements

19. Outfall DW2 Total Flow Duration of Discharge pH TSS TRC (if chlorinating) Ammonia (if chloraminating) Monitoring Requirements

20. Best Management Practices • Permit requires the development of a BMP plan • Describe what will be done to reduce pollution from temporary discharges such as overflows and line flushing

21. Representative Outfalls • Representative outfalls cover activities at similar sites • Sampling would only have to be performed at selected outfalls • Provide documentation showing that the discharges from these activities will be similar in quality and nature

22. Frequently Asked Questions • Are all water systems required to get coverage under the discharge permit? • Do all water systems need coverage under both outfalls? • How is the state going to handle chlorine for discharges into road ditches? • What if we can not get a sample during a discharge?

23. Frequently Asked Questions • The permit requires that no chemicals be added without DENR notification. How will that work? • Can we use chemicals for dechlorination? • Why would I want coverage under this permit instead of the temporary one? • What are the next steps?

24. For more information • Kelli Buscher • kelli.buscher@state.sd.us • 605.773.3351 • Anthony Mueske • anthony.mueske@state.sd.us • 605.773.3351 • http://www.state.sd.us/denr/DES/Surfacewater/WTP.htm