LONG TERM 1 ENHANCED SURFACE WATER TREATMENT AND FILTER BACKWASH PROPOSED RULE

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LONG TERM 1 ENHANCED SURFACE WATER TREATMENT AND
FILTER BACKWASH PROPOSED RULE

• US EPA
• Office of Ground Water and Drinking Water
• May 30, 2000

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OVERVIEW OF PRESENTATION

• Background
• Statutory Authority
• Public Health Concerns
• Rule Development Process
• Regulatory Provisions
• Long Term 1 Enhanced Surface Water Treatment
  Provisions
• Filter Backwash Recycling Provisions

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BACKGROUND

• STATUTORY AUTHORITY
• SDWA Section 1412 (b)(2)(C)
• Requires final Federal Register publication of a
  Enhanced Surface Water Treatment Rule by November
  2000
• SDWA Section 1412 (b)(14)
• Requires EPA to develop regulations that,
  Govern the recycling of filter backwash within
  the treatment process of a public water system by
  August 2000 unless such recycling has been
  addressed by the Administrators ESWTR prior to
  such date

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BACKGROUND

• PUBLIC HEALTH - CRYPTOSPORIDIUM
• Major public health concern because
• is not inactivated by standard disinfection
  practices
• causes gastrointestinal illness, diarrhea,
  abdominal discomfort, nausea, vomiting
  (occasionally death)
• severity and duration of illness is often greater
  for immunocompromised persons
• Sources include human animal feces (septic
  tanks, wastewater, feedlots, dairies, etc.)

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BACKGROUND

• PUBLIC HEALTH - OUTBREAKS RISK
• Cryptosporidiosis outbreaks
• Milwaukee, WI - 1993
• Carrolton, GA -1987
• Jackson County, OR - 1992 (small system)
• Cook County, MN - 1993 (small system)
• Reported CDC outbreaks substantially
  underestimate actual number of outbreaks
• Existing SWTR
• does not address Cryptosporidium
• is not protective for source waters with high
  microbial pathogen concentrations

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BACKGROUND

• BASELINE - RULE APPLICABILITY
• LT1 Provisions
• 11,593 public water systems utilize surface water
  or ground water under direct influence of surface
  water (GWUDI) and serve lt 10,000 persons
• Specific components apply to smaller subsets of
  the total universe
• FBR Provisions
• 4,636 conventional and direct filtration systems
  utilize surface water or (GWUDI) recycle filter
  backwash
• 3,538 systems serve lt 10,000 persons, 1,098
  systems serve gt than 10,000 persons
• Specific components apply to smaller subsets

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BACKGROUND

• RULE DEVELOPMENT PROCESS
• SBREFA Consultations
• Seven panel meetings with 16 Small Entity
  Representatives (SERs) from the water treatment
  industry, Small Business Administration (SBA),
  Office of Management and Budget (OMB)
• Stakeholders Meetings
• Denver, CO - 7/98 Dallas, TX 3/99
• 6/99 Draft Proposed LT1FBR
• 20 comment letters received (5 States, trade
  associations and utilities, and an environmental
  group)

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REGULATORY PROVISIONS

• LT1 PROVISIONS
• Seven (7) components
• Only applies to public water systems serving
  lt10,000
• Modeled after the Interim Enhanced Surface Water
  Treatment Rule (IEWSTR)
• FBR PROVISIONS
• Three (3) components
• Applies to public water systems of all sizes that
  recycle

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REGULATORY PROVISIONS

• LT1 PROVISIONS
• Revised Combined Filter Effluent Turbidity Limits
  
• Individual Filter Turbidity Monitoring
• Disinfection Benchmarking
• 2-Log Cryptosporidium Removal
• Inclusion of Cryptosporidium in definition of
  GWUDI
• Inclusion of Cryptosporidium into existing
  watershed requirements
• Requirement that all newly constructed reservoirs
  be covered

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REGULATORY PROVISIONS

• LT1 - COMBINED FILTER EFFLUENT TURBIDITY
• Conventional direct filtration membranes -
  0.3 NTU 95, and 1 NTU Max
• Slow sand diatomaceous earth filtration -
  continue to meet 1 NTU 95, and 5 NTU Max (SWTR)
• All other filtered systems must demonstrate to
  State they achieve 2-log and State sets approved
  turbidity levels
• Data from 200 plants in 16 States show
• gt42 of systems meet 0.3 NTU 95
• gt84 of systems never exceed 1 NTU max

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REGULATORY PROVISIONS

• LT1 - INDIVIDUAL FILTER TURBIDITY MONITORING
• Requires conventional direct filtration systems
  to continuously (e.g., 1 sample every 15 minutes)
  monitor turbidity of each filter
• If individual filter turbidity gt 1 NTU in 2
  consecutive measurements (same filter) a system
  must
• Report each month trigger is exceeded
• Conduct an Individual Filter Self Assessment if
  report is generated 3 months in a row on the same
  filter
• Arrange for State to conduct a Comprehensive
  Performance Evaluation (CPE) if report is
  generated 2 months in a row in both months
  turbidity gt 2 NTU in 2 consecutive measurements
  on the same filter

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REGULATORY PROVISIONS

• LT1 - DISINFECTION BENCHMARKING
• Systems must develop a disinfection profile based
  on calculations of Giardia lamblia inactivation
  over the period of a year unless they can
  demonstrate through applicability monitoring that
  TTHM HAA5 levels are lt 64?g/L and lt48 ?g/L
  respectively
• Monitoring must be during warmest water
  temperature month at point of maximum residence
  time
• Disinfection Profile - Weekly measurement of
  temperature, pH, residual chlorine, and peak
  hourly flow used to calculate Giardia log
  inactivation

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REGULATORY PROVISIONS

• LT1 - DISINFECTION BENCHMARKING
• Average of weekly measurements is monthly
  inactivation value
• Lowest monthly value is the Disinfection
  Benchmark
• If a system changes disinfection practices
  (moving point of disinfection, changing
  disinfectant, changing disinfection process, or
  others as determined by State) they must
  determine the benchmark and consult with the
  State to receive approval for the change in order
  to assure that existing microbial protection is
  not reduced as a result of the change

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REGULATORY PROVISIONS

• LT1 - FLEXIBILITY BURDEN REDUCTION
• Profiling was reduced from daily to weekly
• Applicability Monitoring reduced from quarterly
  at four locations to one-time during critical
  period
• Individual Filter Monitoring - removed 0.5 NTU
  trigger at 4 hours into filter run requirement
  that system perform a filter profile if exceed a
  trigger
• Rule allows States to use TTHM HAA5 data that
  meet specific criteria to serve as applicability
  monitoring samples

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REGULATORY PROVISIONS

• FBR PROVISIONS
• Recycle to be returned prior to point of primary
  coagulant addition
• Systems which practice direct filtration to
  report their recycle treatment capability to
  State
• Systems who recycle without equalization or
  treatment to gather recycle data and submit
  report to State

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REGULATORY PROVISIONS

• FBR - RECYCLE PRIOR TO COAGULANT ADDITION
• Conventional and direct filtration systems which
  recycle must return recycle prior to point of
  primary coagulation addition
• Softening plants contact clarification systems
  may recycle process solids to alternate locations
• States may establish alternative locations for
  systems to recycle to on a site-specific basis

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REGULATORY PROVISIONS

• FBR - DIRECT RECYCLE SELF ASSESSMENT
• Conventional filtration systems which recycle
  without treatment or equalization of recycle and
  operate lt 20 filters must perform a
  self-assessment
• Assessment - Daily monitoring of flows number
  of filters in operation during backwashing for
  one month to determine whether State approved
  operating capacity is exceeded during recycle
  events
• State determines whether modifications to recycle
  practice must be made to reduce risk based on
  Self Assessment results.

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REGULATORY PROVISIONS

• FBR - DIRECT FILTRATION REPORTING
• Direct filtration plants that recycle must report
  to the State whether flow equalization or
  treatment is provided
• State determines whether modifications to recycle
  practice must be made to reduce potential risks

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REGULATORY PROVISIONS

• FBR - FLEXIBILITY BURDEN REDUCTION
• Softening plants contact clarification systems
  may recycle process solids to alternate locations
• States may establish alternative locations for
  systems to recycle to on a site-specific basis
• Based on results of self assessment report and
  direct filtration reports, State determines
  whether modifications to recycle practice must be
  made to reduce risk