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Overview of Safe Drinking Water Standards

Overview of Safe Drinking Water Standards. Spring, 2008 Drinking Water Program Office of Environmental Public Health Public Health Division Oregon Department of Human Services. Which Contaminants Does EPA Regulate?. May have adverse effect on the health of persons, and

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Overview of Safe Drinking Water Standards

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  1. Overview ofSafe Drinking Water Standards Spring, 2008 Drinking Water Program Office of Environmental Public Health Public Health Division Oregon Department of Human Services

  2. Which Contaminants Does EPA Regulate? • May have adverse effect on the health of persons, and • Known or likely to occur in public drinking water systems with frequencies and levels of health concern, and • Regulation presents meaningful opportunity for health risk reduction for persons served by public water systems

  3. Forms of EPA Drinking Water Standards • Maximum Contaminant Level Goal (MCLG) – no known or anticipated adverse health effects, with margin of safety • Maximum Contaminant Level (MCL) – enforceable standard set as close as feasible to MCLG considering technology, treatment, cost, field conditions • Treatment Technique (TT) – in lieu of MCL when levels can’t be measured • Action Level (AL) – triggers action by water supplier

  4. Setting Standards - Health Effects Matter • Acute effects – occur within hours or days of the time that a person consumes a contaminant at high levels. Example: acute gastrointestinal illness. • Chronic effects – occur after people consume a contaminant at low levels over many years. Examples: cancers, organ damage

  5. Setting Standards - Exposure Matters • Long-term exposure – same people daily (communities, schools, workplaces): • Acute contaminants, and • Chronic contaminants • Short-term exposure – different people daily (campgrounds, parks, motels, restaurants): • Acute contaminants • EPA bases drinking water exposure on 2 liters per day

  6. 91 Regulated Drinking Water Contaminants • 7 Microbials (bacteria, viruses, parasites) • 7 Disinfection by-products (trihalomethanes, haloacetic acids) • 16 Inorganic chemicals (arsenic, nitrate, lead) • 56 Organic chemicals (solvents, pesticides) • 5 Radiologic contaminants (uranium)

  7. EPA Standards - History

  8. More EPA Standards in 2005-07: • Parasitic microorganisms • Disinfection by-products • Arsenic (increased protection) • Groundwater (viruses) • Lead and Copper revisions

  9. Microbial ContaminantsGeneral • Concern – Acute waterborne disease outbreaks in public water systems • Purpose – Protect public health by controlling disease-causing organisms from humans and animals: • Bacteria (Legionella, Campylobacter) • Viruses (Norovirus) • Parasites (Giardia, Cryptosporidium)

  10. Microbial ContaminantsGeneral • Health concern - acute gastrointestinal illness (AGI) • Nausea • Diarrhea • Cramps • Headaches • Particular risk to infants, children, elderly, immunocompromised individuals

  11. US Waterborne Disease Outbreaks 2003-04 (CDC)

  12. Microbials – Coliform Bacteria • Coliform bacteria do not generally cause disease, but are respected indicators: • Total coliform = environmental contamination • Fecal coliform/E. coli = fecal contamination • Rule history • National regulation for coliform bacteria - 1975 • Total Coliform Rule – 1989

  13. Microbials – Coliform Bacteria • Application – ALL public water systems, conduct monthly or quarterly coliform sampling from the distribution system, based on population • MCLs • Based on presence/absence in samples taken, including repeat samples • Small systems – more than 1 coliform-present sample per month/quarter • Large systems – more than 5% coliform-present samples per month • Confirmed fecal/E. coli = boil notice

  14. Microbials – Surface Water Treatment • Health concern – Waterborne disease outbreaks from Giardia and Cryptosporidium in filtered and unfiltered surface water systems • Purpose – Improve public water protection through control of viruses, Giardia, Cryptosporidium • Application – All public water systems using surface water, or using groundwater under the direct influence of surface water

  15. Microbials – Surface Water Sources • Rule history • National regulation for turbidity (particulates) - 1975 • Surface Water Treatment - 1989 • Interim Enhanced Surface Water Treatment – 1998 • Filter Backwash – 2001 • Long-term 1 – 2002 • Long-term 2 - 2006

  16. Microbials – Surface Water Treatment • Specific requirements • All surface water systems must disinfect • All must filter unless filter avoidance criteria met • Achieve minimum filtration and disinfection effectiveness: • 99.99% virus reduction • 99.9% Giardia reduction • 99% Cryptosporidium reduction • Extra treatment if source water Cryptosporidium levels are high • Correct deficiencies identified in sanitary surveys

  17. Microbials – Groundwater Rule • Health concern – Virus-like outbreaks in undisinfected ground water systems, no agent found • Purpose – Increase protection against viruses and bacteria in public water systems using ground water sources that are susceptible to fecal contamination, estimated at 8% of all public wells

  18. Microbials - Groundwater • Application – all public water systems using ground water • Rule history • National regulation for coliform bacteria - 1975 • Coliform Rule – 1989 • Ground Water Rule – 2006

  19. Microbials – Groundwater Rule • Specific requirements • Sanitary surveys to identify deficiencies, water system must correct or provide disinfection treatment • Source water monitoring • Triggered monitoring if coliform detected in the distribution system • Assessment monitoring for fecal indicators at State discretion

  20. Microbials – Groundwater Rule • Specific requirements (continued) • Treatment techniques • Correct all deficiencies, or • Provide alternate water source, or • Eliminate source of contamination, or • Provide treatment to reduce viruses 99.99%

  21. Disinfection By-products • Formed from reaction of disinfectants used to kill microbes with natural organic substances in water called precursors • Health concern - bladder cancer and reproductive effects • Purpose – Improve public health protection by reducing exposure to disinfection by-products and disinfectant residuals

  22. Disinfection By-products • Application – all community and nontransient noncommunity water systems that add a disinfectant or distribute water that has been disinfected • Rule history • National regulation for total trihalomethanes – 1979 • Stage 1 Disinfection By-products Rule – 1998 • Stage 2 Disinfection By-products Rule – 2006

  23. Disinfection By-products • Rule requirements - Stage 1 • Revise standard for total trihalomethanes (TTHM) • New MCLs for haloacetic acids (HAA), disinfectant residuals • Meet quarterly running annual average across the water distribution system for TTHM, HHA (1 sample/plant/year to 4/plant/quarter) • Meet maximum residual disinfectant levels • Treatment technique for precursor removal based on TOC, alkalinity (enhanced coagulation)

  24. Disinfection By-products • Rule requirements - Stage 2 • Determine sampling locations, 2007-10 • distribution system evaluation to determine sampling locations • Small system waiver • Begin monitoring, 2012-14 • Meet TTHM and HHA levels as a locational quarterly running annual average at each sampling location starting 2013-2014

  25. Lead and Copper • Lead and copper primarily enter the water via corrosion of building plumbing and fixtures and can be minimized by corrosion control treatment of the drinking water supply • Health concern - Lead can damage the brain, blood cells, and kidneys, especially for infants and young children. Copper can cause gastrointestinal distress. • Purpose – Protect public health by minimizing exposure to lead and copper at the tap

  26. Lead and Copper • Application – all community and nontransient noncommunity water systems • Rule history • National regulation for lead – 1975 • Oregon ban on lead solder - 1985 • Lead and Copper Rule – 1991 • LCR minor revisions – 2000 • LCR clarifications - 2007

  27. Lead and Copper • Rule requirements • Identify high-risk homes for sampling sites (5-100) • Sample 1-liter standing water • Meet action levels for lead and copper at 90% of sites • If lead action level exceeded: • Conduct public education, and • Install corrosion control treatment, or • Provide alternate water source, or • Replace plumbing

  28. Inorganic Contaminants • Purpose – Protect public health by reducing exposure to 16 metals and minerals, both naturally-occurring and from agriculture/industry • Health concern – Primarily chronic effects on organs, blood, bones, including cancer. Nitrate has acute effects on blood for infants • Application – all community and nontransient noncommunity water systems. Nitrate applies to all water systems, and arsenic monitoring.

  29. Inorganic Contaminants • Rule history • National regulation for 10 inorganics – 1975 • Phase 2 Rule – 1991 • Phase 5 Rule – 1992 • Arsenic Rule – 2001 • Sampling • Surface water systems, annual • Ground water systems, every three years • Reductions/waivers, once every 6 or 9 years • Nitrate, annual

  30. Organic Chemicals • Purpose – Protect public health by reducing exposure to 56 volatile (VOC) and synthetic (SOC) organic chemicals including industrial solvents/chemicals and pesticides • Health concern – Primarily chronic health effects on blood, organs, nervous system, including cancer • Application – All community and nontransient noncommunity water systems

  31. Organic Chemicals • Rule history • National regulation for 6 organics – 1975 • Phase 1 Rule - 1987 • Phase 2 Rule – 1991 • Phase 5 Rule – 1992 • Sampling • One test every three years • Systems serving over 3,300 must test twice every 3 years for SOCs • Surface water systems must test for VOCs annually

  32. Radioactive Contaminants • Purpose – Protect public health by reducing exposure to 5 radioactive contaminants, both geologic and man-made. Rarely found in Oregon • Health concern – Primarily cancer from long-term exposure • Application – All community water systems

  33. Radioactive Contaminants • Rule history • National regulation for 4 contaminants – 1975 • Radionuclide Rule – 2000 • Radium 226 & 228 • Uranium • Sampling • Initial quarterly tests for one year • Once every 3, 6, or 9 years based on initial results

  34. Setting Future Standards • Contaminant Candidate List • Unregulated Contaminant Monitoring • National Contaminant Occurrence Database • Consider five contaminants every five years, regulate or not

  35. Contaminant Candidate List 3 - 2008 • 7500 contaminants evaluated • 104 candidate contaminants listed: • 11 microbials – waterborne pathogens • 93 chemicals • Commercial chemicals • Biological toxins • Pesticides • Disinfection by-products

  36. Possible Future Standards • Radon • Revise coliform rule • Distribution protection • Emerging contaminants • MTBE (gasoline additive) • Perchlorate (rocket fuel, munitions) • Pharmaceuticals, personal care products • Pesticides

  37. 971-673-0405 oregon.gov/dhs/ph/dwp For More Information!

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