Overview of Safe Drinking Water Standards

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Overview ofSafe Drinking Water Standards

• Spring, 2008
• Drinking Water Program
• Office of Environmental Public Health
• Public Health Division
• Oregon Department of Human Services

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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

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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 cant be measured
• Action Level (AL) triggers action by water
  supplier

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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

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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

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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)

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EPA Standards - History
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More EPA Standards in 2005-07

• Parasitic microorganisms
• Disinfection by-products
• Arsenic (increased protection)
• Groundwater (viruses)
• Lead and Copper revisions

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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)

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Microbial ContaminantsGeneral

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

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US Waterborne Disease Outbreaks 2003-04 (CDC)
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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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)

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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

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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

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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

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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

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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.

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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

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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

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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

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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

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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

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Setting Future Standards

• Contaminant Candidate List
• Unregulated Contaminant Monitoring
• National Contaminant Occurrence Database
• Consider five contaminants every five years,
  regulate or not

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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

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Possible Future Standards

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

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For More Information!

• 971-673-0405
• oregon.gov/dhs/ph/dwp