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CALIFORNIA’S CRITERIA FOR GROUNDWATER RECHARGE WITH RECLAIMED WATER

CALIFORNIA’S CRITERIA FOR GROUNDWATER RECHARGE WITH RECLAIMED WATER. Bob Hultquist Drinking Water Program California Dept. of Health Services bhultqui@dhs.ca.gov. Recycled Water. California Water Code

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CALIFORNIA’S CRITERIA FOR GROUNDWATER RECHARGE WITH RECLAIMED WATER

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  1. CALIFORNIA’S CRITERIA FOR GROUNDWATER RECHARGE WITH RECLAIMED WATER Bob Hultquist Drinking Water Program California Dept. of Health Services bhultqui@dhs.ca.gov

  2. Recycled Water • California Water Code Recycled water – … water which, as a result of treatment of waste, is suitable for a direct beneficial use or controlled use …

  3. Potable Reuse Issues • The existing set of drinking water standards are not comprehensive and do not define safe drinking water • We keep finding additional chemicals in toxic concentrations that evade “best available treatment • There is little health effects information on low doses of pharmaceuticals and endocrine disrupters

  4. Degrees of Potable Reuse Potential level of contamination & risk or treatment required Safe Drinking Water Act & Clean Water Act 0 100 Reclaimed water contribution (%)

  5. Groundwater Recharge Studies and Reports • 1962 Whittier Narrows • 1976 Water Factory 21 • 1984 LACSD Health Effects Study • 1987 Scientific Advisory Panel • 1996 Epidemiological study at LACSD • 1998 NRC report on potable reuse • 1999 Epidemiological study at LACSD • Underway SARWQH study - OCWD • Underway SAT study - LACSD et al. • Underway OCWD & WBMWD permits

  6. Draft Recharge Criteria • Reclaimed water • Aquifer used as a drinking water source • Indirect potable reuse • Effective natural barrier • Time to identify and respond to problems

  7. Criteria Goals • Address spreading and direct injection • Safe relative to other major California water sources • Protect the groundwater • (Wellhead treatment not an option)

  8. Criteria Goals - 2 • Set health protective criteria that promote regulator, public water system, health agency, medical community, public, and policy maker confidence

  9. Public Concern/Opposition • Risk to children and the ill • Absolutely safe? • Emerging concerns such as pharmaceuticals, prions and endocrine disrupters • Distrust of government • Property values • Growth inducing • Don’t want other people’s waste • Yuck

  10. Draft Criteria • Pathogenic microorganisms • Regulated Chemicals • Nitrogen compounds • Unregulated chemicals

  11. Microorganism Control • Secondary treatment • Filtration • 2 NTU • Disinfection • 2.2 total coliform MPN/100mL • Residence time in the environment • Spreading – 6 months • Direct injection – 12 months

  12. Regulated Chemical Control • Drinking Water Standards • Developed as needed (occurrence) and only when health effects, detection method, and treatment are known • Set of DWS not sufficient for impaired sources or indirect potable reuse

  13. Nitrogen Compound Control • A total nitrogen standard of 5 mg/L is set because all forms of nitrogen could convert to nitrate or nitrite in the groundwater

  14. Other Chemical Concerns • Unregulated contaminants—the usual suspects (ALs, Priority Pollutants) • Gross organic matter(TOC) • Contemporary concerns • Endocrine disrupting (or hormonally active) contaminants • “Industrial” endocrine disruptors • Pharmaceuticals

  15. Emerging contaminants • Unknown with regard to detection, treatment, human health effects at environmental concentrations • Often information available about effects at high levels (drugs), or ecological effects (endocrine disruptors)

  16. Unregulated Chemical Control - Monitoring • Monitor for Chemicals with ALs, Priority Pollutants • But too many compounds to monitor for everything else • Plus, this is a dynamic situation • Industrial practices change • Pharmaceutical prescription preferences change • Public perceptions change

  17. Unregulated Chemical Control – Monitoring (2) Consider groups of contaminants that might be representative for monitoring. These would be selected not necessarily because they have specific human health effects, but because their presence may indicated that other chemicals of similar characteristics or origin.

  18. Monitoring - Endocrine Disruptors (Hormones) • Hormones—“disruptors,” in that doing what they are supposed to, just to someone else. These hormones are representative hormones plus surrogates for other steroid hormones. DHS is considering including for monitoring: • ethinyl estradiol • 17-B estradiol • estrone

  19. Monitoring - “Industrial” Endocrine Disruptors • These might include • Alkyphenols and alkyphenol polyethoxylates (e.g., octylphenol and octyphenol polyethoxylate andnonylphenols and nonylphenol polyethoxylate (surfactants, detergents)—estrogenic activity • PBDE’s—flame retardants—anti-thyroid and may cause neurodevelopmental effects

  20. Monitoring - Pharmaceuticals & Surrogates • These have been found in wastewater and represent the variety of drugs. • Acetominophen—pain treatment • Amoxicillin—antibiotic • Carbamazepine—anti-epilepsy drug • Iodinated contrast media—medical imaging • Triclosan—consumer/household bactericidal soap

  21. Unregulated Chemical Control – Source Control • Clean Water Act type source control for all projects • Plus- the source control program must be supplemented with an effort to further identify and control selected contaminants of public health concern

  22. Unregulated Chemical Control – TOC • Use TOC as a surrogate for unregulated organic chemicals • A small fraction of the TOC may be chemicals present in toxic concentrations

  23. Unregulated Chemical Control - TOC • A treatment performance standard (not water quality objective) of • (0.5 mg/L TOC)/RWC • (new or increased RWC projects) • Establish a treatment goal of (0.3 mg/L TOC)/RWC

  24. Unregulated Chemical Control • >50 % RWC requires: • A demonstration that operating under 50% causes no problems • Advanced oxidation with a yet to be determined UV and hydrogen peroxide dose • Testing for tentatively identified compounds (TICs) • Peer review by independent advisory panel

  25. Status • 6 approved projects • 4 projects under review • Draft evolving (watch the WEB page) • The criteria will become regulation

  26. For more information: DHS Drinking Water Program’s website http://www.dhs.ca.gov/ps/ddwem/

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