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Surface Water Treatment Rule Ground Water Reclassification. PWS TYPE:STATE DETERMINATION BY: CWS6/29/94 NCWS6/29/99 40 CFR 142.16 (b)(2)(B) _______________________________________________________________________________ DETERMINATIONACTION Direct influence Meet avoidance criteria within of surface water 18 months or Install filtration within 18 months 40 CFR34914
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1. Surface Water Treatment Rule Bob Clement
Drinking Water Program
U.S. EPA Region 8
2. Surface Water Treatment RuleGround Water Reclassification
3. Surface Water Treatment RuleGeneral Requirements
4. Surface Water Treatment RuleGeneral Requirements
5. Cryptosporidium
6. Cryptosporidium
7. Cryptosporidium It would take up to 29,000 mg/l of CL2 to inactivate crypto.
Traditional chlorination doesn’t work. Physical removal by treatment is the only method of reduction for crypto.
8. Cryptosporidium
9. Surface Water Treatment Benefits
10. Turbidity Monitoring RequirementsFiltered Systems
11. Turbidity Performance RequirementsFiltered Systems
12. Turbidity Performance RequirementsFiltered Systems
13. Turbidity Standards Systems using a technology other than conventional, direct, slow sand or diatomaceous earth filtration are in compliance if: system demonstrates to the State that alternative filtration technology in combination with disinfection … (40 CFR 141.73(d))
14. Turbidity Standards … alternative filtration technology in combination with disinfection consistently achieves removal and/or inactivation of:
99.9% of Giardia lamblia cysts (filtration + disinfection)
99.99% of viruses (filtration + disinfection)
99% of Cryptosporidium (filtration alone) (Interim Enhanced SWTR 12/16/98)
15. Disinfection Requirements for Filtered Systems
16. Disinfection RequirementsEntry Point to Distribution System Residual entering distribution system
cannot be < 0.2 mg/L for > 4 hours
> 3300 people - continuous monitoring (grab sample allowed every 4 hours up to 5 days if monitoring equipment fails) 40 CFR 141.74(c)(2)
1-4 samples / day allowed for systems serving < 3301 people
If residual is < 0.2 mg/L, must notify the State before end of next business day
17. Disinfection RequirementsEntry Point to Distribution System 1-4 samples / day allowed for systems serving < 3301 people
SIZE # OF SAMPLES
< 500 1
501-1000 2
1001-2500 3
2501-3,300 4
If residual is < 0.2 mg/L, must notify the State before end of next business day
40 CFR 141.74(c)(2)
18. Distribution System Disinfection Requirements Residual cannot be absent or HPC > 500ml in > 5% of samples/month for 2 mo.
Monitoring locations / frequency (same as total coliform samples)
For systems receiving groundwater and surface water, States may allow monitoring at surface water sites 40 CFR 141.74(c)(3)(i&ii)
Above requirements do not apply if HPC monitoring not feasible and State determines adequacy of disinfection
19. Recommended Removal and Disinfection Levels
20. Recommended Removal and Disinfection Levels
21. Disinfection Contact Times