# Presentation: 108593

## 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

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

## 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 Administrator’s ESWTR prior to such date”

## 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.)

## 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

## 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 < 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 < 10,000 persons, 1,098 systems serve _>_ than 10,000 persons
- Specific components apply to smaller subsets

## 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)

## REGULATORY PROVISIONS

**LT1 PROVISIONS**** **
- Seven (7) components
- Only applies to public water systems serving <10,000
- 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

## 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

## 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:
- >42% of systems meet 0.3 NTU 95%
- >84% of systems never exceed 1 NTU max

## 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 > 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 > 2 NTU in 2 consecutive measurements on the _same_ filter

## 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 < 64g/L and <48 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

## 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

## 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

## 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

## 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

## REGULATORY PROVISIONS

**FBR - DIRECT RECYCLE  SELF ASSESSMENT**
- Conventional filtration systems which recycle _without_ treatment or equalization of recycle and operate < 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.

## 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

## 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