# Presentation: 800068

## The Stage 2 D/DBPR and LT2ESWTR--Where are We Going

- J. Alan Roberson, P.E.
- Director of Regulatory Affairs
- AWWA-Washington, DC

## Outline

- Overview of the M/DBP Cluster
- Overview of IESWTR and Stage 1 D/DBPR
- Preliminary ICR Data Analysis
- Where the LT2ESWTR and Stage 2 D/DBPR May Be Going

## Microbial/Disinfection By-Products (M/DBP) Cluster

- Balancing of acute microbial risks with chronic chemical risk a unique regulatory challenge
- EPA used negotiative processes instead of traditional proposal and public comment
- ‘92 & ‘93 negotiated rulemaking (Reg-Neg) led to ‘94 proposals for ICR, Stage 1 D/DBPR , & IESWTR
- ICR data would be used for selection of IESWTR option
- ICR delayed due to multiple problems
- ICR monitoring started in July, 1997 instead of October, 1994
- Led to ‘97 Federal Advisory Committee (FACA)

## 1997 Federal Advisory Committee (FACA) Process 

- Looked at components of ‘94 proposals
- What can we use to meet statutory deadlines?
- FACA met through March-July, 1997
- Agreement in Principle signed in July, 1997
- Notice of Data Availability published in *Federal Register *on March 31, 1998
- IESWTR focused on new turbidity standards
- Profiling/benchmarking provisions
- Minor changes to Stage 1 D/DBPR

## The First Regulations in the M/DBP Cluster

- Stage 1 D/DBPR & IESWTR published in the *Federal Register *on Dec. 16, 1998
- New MCLs and treatment techniques
- Optimizing existing treatment rather than major shifts to alternative technologies
- Costs not insignificant--$1 Billion/year
- Compliance in 2001 & 2003
- LT1ESWTR for systems <10,000 people
- Final in 2000 and compliance in 2003

## Stage 1 D/DBPR

- Lowers existing MCL for TTHM from 0.10 mg/l (100 ug/l) to 0.080 mg/l (80 ug/l)
- Applies to all systems (except for transients)
- Phased compliance for small systems
- Establishes new MCLs
- HAA5--0.060 mg/l (60 ug/l)
- MCAA, DCAA, TCAA, MBAA, DBAA
- Chlorite--1.0 mg/l
- Bromate--0.010 mg/l (10 ug/l)

## Stage 1 D/DBPR (cont.)

- Establishes Maximum Residual Disinfectants Levels (MRDLs) for common disinfectants
- Chlorine & chloramine--4.0 mg/l (as Cl2)
- Chlorine Dioxide--0.8 mg/l (as ClO2)
- Daily monitoring for chlorine dioxide & transients
- MRDLs can be exceeded for short periods
- Enhanced coagulation and softening treatment technique for TOC removal
- Step 1 matrix & Step 2 process (with “outs”)

## IESWTR

- Surface water systems serving >10,000 people
- 2 logs *Cryptosporidium* removal credit for conventional treatment
- Lowered combined filter turbidity
- From <0.5 NTU to <0.3 NTU 95% of the time
- From <5 NTU to <1 NTU as a maximum
- Monitor treatment processes carefully
- Compliance still based on 4-hr. intervals

## IESWTR (cont.)

- Individual filter turbidimeters
- Readings every fifteen minutes
- Exceptions reported to state when:
- >1.0 NTU for any 2 15-min. readings or >0.5 NTU for any 2 readings after 1st 4 hours
- Develop filter profile within 7 days
- Self-assessment for >1.0 NTU for 2 15-min. readings at any time in 3 consecutive months
- Comprehensive Performance Evaluation for >1.0 NTU in 2 consecutive months

## IESWTR (cont.)

- Profiling & Benchmarking
- TTHM >0.064 mg/l or HAA5>0.048 mg/l
- Develop profile-daily inactivation for one year based on daily measurements of operational data
- Calculate benchmark & consult with State
- Lowest monthly average inactivation
- Cover new finished water reservoirs
- Sanitary survey requirements

## Information Collection Rule

- DBP and microbial monitoring data to be used for the Stage 2 D/DBPR & LT2ESWTR
- 18 months of data from the systems serving >100,000 people--296 utilities--501 plants
- July, 1997 to December, 1998
- Data is currently being analyzed
- A lot more work than initially thought
- Bench- and pilot-scale treatment studies for systems with high levels of DBP precursors

## ICR Data Analysis Tools

- ICRFED--the very large Federal database for all monitoring & engineering data
- Auxiliary databases developed for more relevant data (Access-based)
- Available on CD from EPA
- Stage 1 baseline & Stage 2 options
- Surface Water Analytical Tool (SWAT)
- Results extrapolated for medium & small systems
- Expert panel for large groundwater systems

**Aux 2**
- CT & Disinfectant Decay

**Aux 3**
- Enhanced Coagulation

**Aux 4**
- Sludge Production   .

**Aux 5**
- Washwater Return

**Aux 6**
- Distribution System   DBPs

**Query**
**Tool**

**Aux 8**
- Model Interface/ Database

- Auxiliary Database Relationships

## Surface Water Analysis Tool  Data Process Overview

## Final Large Surface Water Stage 1 Baseline Technology Cost Levels

## Historical Comparison of TTHM Cumul. Freq. Distributions

- AWWARF Survey 1984-86
- 727 utilities
- NOMS--1976-77
- 450 utilities
- NORS--1975
- 490 utilities
- ICR--three quarters of data
- 469 plants; 1002 quarterly averages

## Slide 17

## Stage 1 Baseline TTHM Levels

## Stage 1 Baseline HAA5 Levels

## TTHM v. HAA5 Plot--Stage 1 Baseline--Running Annual Averages

## TTHM v. HAA5 Plot--Stage 1 Baseline--Single Highest

## TTHM v. HAA5--ICR Maximum Values Based on 4 Quarters

## Microbial Monitoring

- Source water monitoring
*Giardia, Cryptosporidium*, viruses, & coliforms
- Virus monitoring “out”
- Finished water monitoring
*Giardia & Cryptosporidium* monitoring based on triggers in source water monitoring
- Not many plants monitored finished water
- Handful of detects in finished water

## Microbial Monitoring (cont.)

*Cryptosporidium *results (total)
- 93% non-detects
- Higher detections in flowing streams versus reservoirs
- Supplemental survey results--higher detectsions
*Giardia *results (total)
- 82 % non-detects
- Similar higher detections in flowing streams
* *Virus results--77% non-detects

## Cryptosporidium ResultsPercentage Non-Detects--18 Months ICR Data

## Stage 2 D/DBPR & LT2ESWTR

- Part of the ‘92-’93 Reg-Neg agreement
- EPA committed to meeting their deadlines
- How far do we need to go beyond the Stage 1 D/DBPR & IESWTR?
- Negotiations April, 1999-July, 2000
- New health effects data & ICR data will be a key part of the negotiations
- Proposal in early 2001
- Final in May, 2002

## The Possible Future for the Stage 2 D/DBPR & LT2ESWTR

- Major changes to the Stage 1 rules
- Single Maximums
*Cryptosporidium* inactivation requirement
- Inactivation based on additional monitoring?
- 1 log additional for systems on flowing streams
- Minor changes to the Stage 1 rules
- Shaving peak DBP levels
- Distribution systems??
- States requirement for cross-connection controls

## Potential Stage 2 D/DBPR  & LT2ESWTR Options

- DBP options
- 80/60 annual average of the maximum
- Similar to location running annual average
-  Single max.--80/60 & 40/30 as MCLs and 120/90 as an Action Level (combinations?)
- Bromate at either 10 ppb or 5 ppb
*Cryptosporidium* inactivation
- 0, 0.5 log, and 2.0 log requirement
- Ultraviolet (UV) light treatment on and off

## The Revised Matrix--41 SWAT Runs

## Comparison of RAA, LRAA and AAM from ICR TTHM Data--Cl2 Plants

## Comparison of RAA, LRAA and AAM from ICR TTHM Data--CLM Plants

## RAA EquivalenciesBased on ICR plant data

## 80/60 RAA EquivalenciesBased on ICR plant data

## Elements of Potential Microbial Framework

- Treatment Characterization
- Characterize source water
- Determine whether additional *Cryptosporidium* monitoring is necessary
- Monitoring criteria for estimating mean *Cryptosporidium* concentrations in source water
- Criteria for classifying potential exposure
- Using mean *Cryptosporidium* concentration and treatment characterization for plant
- Criteria for mitigating potential exposure
- Based on watershed and/or treatment control measures

## Treatment Characterization

- Characterize existing treatment
- Compare to toolbox
- Determine if adequate and whether further action is necessary. (see toolbox)

## Characterize Source Water - Determine if Cryptosporidium monitoring is needed 

**Use one or more of following: fecal coliform, *****E.coli***** , Total coliform, turbidity, as indicator(s) of challenged watershed, and/or watershed characteristics (a watershed index)**
- If indicator(s) (possibly a mean value) is below a critical level, system would be below Crypto occurrence level of concern
- Acceptable misclassification rates a major issue

## Vulnerability Index

- Protective

- Correct

- Incorrect of Concern

## Characterize Source Water - Monitoring Criteria for Estimating Means

- Suggested conditions: 24 monthly samples (2 years)), at least 10L/sample, 40% mean recovery, 50% CV, approximately $500./sample)
- Concerns: high costs (utilities and states),  method is not approved, interpretation of results, high burden on small systems, does not measure infective Crypto, not necessarily capturing peak events
- Benefits: most direct way of determining relative levels of Crypto in the source water

## Characterize Source Water - Monitoring Criteria for Estimating Means

- Plants that must monitor would monitor monthly for *Cryptosporidium* in source water at intake of each plant
- Method 1623 (or equivalent) by approved labs
- At the end of 2 years, systems would calculate
- option 1: mean value
- option 2: highest running annual mean
- Systems would use mean concentration of each plant to classify potential exposure

##  Classifying Potential Categories Distinguish relative amounts of Cryptosporidium in source water

**  ****Plant                     Highest Running                    Action to Reduce**
** ****Category               Annual Mean           ****	****	****Exposure****	****                   ****	****	****	**

-            D		    >1.0/L		             “Toolbox ”

-           C	             >0.1/L to _< _1.0/L	                           “Toolbox”

-            B		 > 0.01/L to _<_ 0.1/L            No Action/“Toolbox ”

-            A 	    _< _0.01/L			No Action

## Treatment Toolbox Options

- Challenges = (1) assigning category shift values and
- (2) implementation transaction costs for utilities and States

## Total Annualized Costs-- Medium & Large SW Systems

## Capital Costs -- Medium & Large SW Systems

## Household Costs -- Medium & Large SW Systems

## Conclusions

- EPA is going to propose a rule in early 2001
- FACA will have to scramble to complete their negotiations by July, 2000
- Most everyone has some concern about high single DBP values
- Most everyone has some concern about systems “vulnerable” to microbial contamination