LONG TERM 1 ENHANCED SURFACE WATER TREATMENT AND FILTER BACKWASH PROPOSED RULE US EPA Office of Ground Water and Drinking Water May 30, 2000

OVERVIEW OF PRESENTATION zBackground yStatutory Authority yPublic Health Concerns yRule Development Process zRegulatory Provisions yLong Term 1 Enhanced Surface Water Treatment Provisions yFilter Backwash Recycling Provisions

BACKGROUND STATUTORY AUTHORITY SDWA Section 1412 (b)(2)(C): zRequires final Federal Register publication of a Enhanced Surface Water Treatment Rule by November 2000 SDWA Section 1412 (b)(14): zRequires 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 Administrator’s ESWTR prior to such date”

BACKGROUND PUBLIC HEALTH - CRYPTOSPORIDIUM zMajor public health concern because: yis not inactivated by standard disinfection practices ycauses gastrointestinal illness, diarrhea, abdominal discomfort, nausea, & vomiting (occasionally death) yseverity and duration of illness is often greater for immunocompromised persons zSources include human & animal feces (septic tanks, wastewater, feedlots, dairies, etc.)

BACKGROUND PUBLIC HEALTH - OUTBREAKS & RISK zCryptosporidiosis outbreaks yMilwaukee, WI yCarrolton, GA yJackson County, OR (small system) yCook County, MN (small system) zReported CDC outbreaks substantially underestimate actual number of outbreaks zExisting SWTR: ydoes not address Cryptosporidium yis not protective for source waters with high microbial pathogen concentrations

BACKGROUND BASELINE - RULE APPLICABILITY LT1 Provisions y11,593 public water systems utilize surface water or ground water under direct influence of surface water (GWUDI) and serve < 10,000 persons ySpecific components apply to smaller subsets of the total universe FBR Provisions y4,636 conventional and direct filtration systems utilize surface water or (GWUDI) & recycle filter backwash y3,538 systems serve than 10,000 persons ySpecific components apply to smaller subsets

BACKGROUND RULE DEVELOPMENT PROCESS zSBREFA Consultations ySeven panel meetings with 16 Small Entity Representatives (SERs) from the water treatment industry, Small Business Administration (SBA), Office of Management and Budget (OMB) zStakeholders Meetings yDenver, CO - 7/98; Dallas, TX 3/99 z6/99 Draft Proposed LT1FBR y20 comment letters received (5 States, trade associations and utilities, and an environmental group)

REGULATORY PROVISIONS LT1 PROVISIONS zSeven (7) components zOnly applies to public water systems serving <10,000 zModeled after the Interim Enhanced Surface Water Treatment Rule (IEWSTR) FBR PROVISIONS zThree (3) components zApplies to public water systems of all sizes that recycle

REGULATORY PROVISIONS LT1 PROVISIONS zRevised Combined Filter Effluent Turbidity Limits zIndividual Filter Turbidity Monitoring zDisinfection Benchmarking z2-Log Cryptosporidium Removal zInclusion of Cryptosporidium in definition of GWUDI zInclusion of Cryptosporidium into existing watershed requirements zRequirement that all newly constructed reservoirs be covered

REGULATORY PROVISIONS LT1 - COMBINED FILTER EFFLUENT TURBIDITY zConventional & direct filtration & membranes NTU 95%, and 1 NTU Max zSlow sand & diatomaceous earth filtration - continue to meet 1 NTU 95%, and 5 NTU Max (SWTR) zAll other filtered systems must demonstrate to State they achieve 2-log and State sets approved turbidity levels zData from ~200 plants in 16 States show: y>42% of systems meet 0.3 NTU 95% y>84% of systems never exceed 1 NTU max

REGULATORY PROVISIONS LT1 - INDIVIDUAL FILTER TURBIDITY MONITORING zRequires conventional & direct filtration systems to continuously (e.g., 1 sample every 15 minutes) monitor turbidity of each filter zIf individual filter turbidity > 1 NTU in 2 consecutive measurements (same filter) a system must yReport each month trigger is exceeded yConduct an Individual Filter Self Assessment if report is generated 3 months in a row on the same filter yArrange for State to conduct a Comprehensive Performance Evaluation (CPE) if report is generated 2 months in a row & in both months turbidity > 2 NTU in 2 consecutive measurements on the same filter

REGULATORY PROVISIONS LT1 - DISINFECTION BENCHMARKING zSystems 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 < 64  g/L and <48  g/L respectively yMonitoring must be during warmest water temperature month & at point of maximum residence time zDisinfection Profile - Weekly measurement of temperature, pH, residual chlorine, and peak hourly flow used to calculate Giardia log inactivation

REGULATORY PROVISIONS LT1 - DISINFECTION BENCHMARKING zAverage of weekly measurements is monthly inactivation value zLowest monthly value is the Disinfection Benchmark zIf 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

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

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

REGULATORY PROVISIONS FBR - RECYCLE PRIOR TO COAGULANT ADDITION zConventional and direct filtration systems which recycle must return recycle prior to point of primary coagulation addition zSoftening plants & contact clarification systems may recycle process solids to alternate locations zStates may establish alternative locations for systems to recycle to on a site-specific basis

REGULATORY PROVISIONS FBR - DIRECT RECYCLE SELF ASSESSMENT zConventional filtration systems which recycle without treatment or equalization of recycle and operate < 20 filters must perform a self-assessment zAssessment - 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 zState determines whether modifications to recycle practice must be made to reduce risk based on Self Assessment results.

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

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