1. National Association of Water Companies October 11, 2010 Eric Burneson, Acting Deputy Director, Office of Ground Water and Drinking Water Potential Approaches for Addressing Groups of Contaminants Under the Safe Drinking Water Act

2. Office of Ground Water and Drinking Water 22 Overview Primary objective – Discuss and solicit input on potential contaminant group(s) for EPA to consider for regulatory action, and the approaches for addressing contaminant groups. Outline  Background SDWA Regulatory Processes  SDWA Regulatory Processes and Opportunities to Consider Contaminant Group(s)  Defining Groups - Factors to consider in developing groups  Preliminary Analysis of Contaminant Groups

3. Office of Ground Water and Drinking Water 333 Statutory Requirements for the Various Drinking Water Regulatory Processes (1996 SDWA Amendments) 1)Contaminant Candidate List (CCL) – SDWA requires EPA to develop a list of contaminants that are known or anticipated to occur in drinking water and to publish the list every five years. 2)Regulatory Determination for CCL – EPA must decide whether or not to regulate at least five CCL contaminants with a national primary drinking water regulation (NPDWR) after evaluating criteria specified under the 1996 SDWA; Publish determinations on a five year cycle. 3)Unregulated Contaminant Monitoring – SDWA requires EPA to establish criteria for a program to monitor unregulated contaminants, and to identify no more than 30 contaminants to be monitored, every five years. 4)Regulation Development - If EPA decides to regulate a contaminant via the regulatory determination process, the Agency has 24 months to propose and 18 months to finalize the Maximum Contaminant Level Goal (MCLG) and the NPDWR. SDWA requires that we evaluate a number of components as part of the standard setting process. 5)Six Year Review – Once a contaminant is regulated, EPA is required to review and, if appropriate, revise the existing National Primary Drinking Water Regulation (NPDWR) every six years. If make a decision to revise a standard, SDWA requires that we evaluate a number of components as part of the standard setting process.

4. Office of Ground Water and Drinking Water 444 Opportunities within SDWA Processes to Consider Contaminant Group(s) 1. For these three stages, like to have increased specificity and confidence in the type of supporting data used (e.g. health and occurrence). 2. When setting the NPDWR, SDWA requires that we: (a) establish the MCLG, (b) set MCL as close as feasible to the MCLG, (c) if cannot establish an MCL (because no reliable/feasible method to measure), establish a Treatment Technique (TT), (d) consider maximizing health risk reduction benefits at a cost justified by the benefits in setting the standard. Draft CCL 1 Final CCL Final Rule (NPDWR) Six Year Review of Existing NPDWRs No further action if make decision to not to regulate (may develop health advisory). Preliminary Regulatory Determinations 1 Final Regulatory Determinations Proposed Rule (NPDWR 1,2 ) Draft UCMR Final UCMR UCMR Monitoring Results

5. Office of Ground Water and Drinking Water 5 Defining Group(s) Potential Factors to Consider Has similar health effect endpoint Removed by common treatment or control processes Measured by common analytical method(s), directly or indirectly, under full scan [Known or likely co-occurrence] The more “promising” groups are likely to have many of these factors in common. 5

6. Office of Ground Water and Drinking Water 6 Examples of Currently Regulated Groups Gross Alpha* (essentially group MCLG and MCL)  MCLG = Zero (carcinogens); MCL = 15 pCi/L (based on feasibility and risk)  Measure “gross alpha” with a single method to determine if exceed MCL  If exceed 15 pCi/L MCL, then measure uranium  Subtract uranium from gross alpha, if still exceed, then speciate to find culprit(s) Beta Photon/Particle Emitters** (also group MCLG and MCL)  MCLG = zero (carcinogens); MCL = 4 mrem/yr (dose)  Measure gross beta/photon emitters (allowed to subtract Potassium 40)  Convert from pCi/L to dose; if exceed then speciate to find culprit(s) Haloacetic Acids (HAA 5)  Individual MCLGs for some; Group MCL = 0.06 mg/L  Measure and add individually to determine if exceed MCL Viruses  MCLG = zero; Specifies Treatment Technique 6 Covers ~ 58 alphas (if don’t include the short lived alphas) ** Covers ~179 individual beta and photon emitters; EPA could have established individual MCLGs of zero for each one but concluded that “despite differences in radiation type, energy, or half-life, the health effects from radiation are identical, although they may occur in different target organs and at different activity levels” (56 FR 33050, July 18 1991 at p. 33079). Common Health One Method Common Health One Method Common Method Common Control Process

7. Office of Ground Water and Drinking Water 7 Preliminary Evaluation Developed a list of all regulated and unregulated CCL 3 contaminants. Identified a universe of ~ 20 contaminant groups ranging from broad categories (e.g. SOCs) to more narrow categories (e.g. nitrosamines). Evaluated the contaminants in the contaminant groups: (1) the critical health endpoint(s), (2) the various treatments used to treat/control each contaminant, and (3) the various analytical methods that can be used to measure the contaminant. Groups with more factors in common represented viable groups; those having limited commonalities unlikely to be good groups. As expected, we found limited convergence of factors for broad groups (e.g. all SOCs, pesticides, etc.) so unlikely candidates for groups. Identified groups for further evaluation and potential regulatory consideration for near term and other groups with more data gaps for future consideration.

8. Office of Ground Water and Drinking Water 8 Groups Initially Identified Volatile Organic Compounds (VOCs) Synthetic Organic Compounds (SOCs) Inorganic Compounds (IOCs) Carcinogenic VOCs Non-carcinogenic VOCs Pesticides Carbamates Organophosphates Chloroacetanilides Triazines Conazoles Disinfection Byproducts Nitrosamines Perfluorinated compounds (PFOS/PFOA/PFCs) Estrogenic Compounds Androgenic Compounds Pharmaceuticals Antibiotics Cholinesterase Inhibitors Thyroid Inhibitors

9. Office of Ground Water and Drinking Water 9 Defining Groups Examples of Broad Groupings FactorsBroad based groupings SOCs (74)Pesticides (103)IOCs (26)VOCs (45) Similar Health Effect Endpoints? Cancer Cholinesterase Inhibition Developmental Cholinesterase Inhibition Cancer Neurological Developmental Testicular Uncommon - Various critical effects. Carcinogens Neurological Common Analytical Method (s)? 525.2 (26) Other methods (16) No DW methods (32) 525.2 (20 chems) 551 (13) 508 (13) + other methods 200.8 (15) 200.7 (1) + other methods (8) No DW methods (2) 524.3 + other methods No DW methods (10) Common treatment or control process Typically GAC, RO, NFTypically GAC, AOP, Ozone, RO/NF Typically RO, IX, Coag/Sed, NF Typically Aeration, GAC

10. Office of Ground Water and Drinking Water 10 Groups for Potential Regulatory Development (Near term)

11. Office of Ground Water and Drinking Water 11 Carcinogenic VOCs Regulated (8) - Benzene Carbon tetrachloride 1,2-dichloroethane 1,2-dichloropropane Dichloromethane Tetrachloroethylene Trichloroethylene Vinyl chloride Unregulated CCL3 (8) - Aniline Benzyl chloride 1,3-butadiene 1,1-dichloroethane Nitrobenzene Oxirane methyl 1,2,3-trichloropropane (TCP) Urethane All carcinogens (MCLG for each is set at zero) Common analytical methods (524.3/524.2, 502.2) Common treatment (Aeration and GAC) Some degree of co-occurrence (based on compliance monitoring data) (SDWA allows setting MCLs as close to MCLG as feasible; MCL for each of these regulated carcinogens is set at the quantitation limit; consider setting a total carcinogenic VOC MCL for group based on feasibility) All carcinogens (such that any MCLG would likely be zero) Common methods (524.2 and/or 524.3) for a few (i.e., 1,2,3-TCP, 1,1- dichloroethane, nitrobenzene and 1,3-butadiene) Effective treatment technologies (Aeration and GAC) for most of the 8 except for 2 (oxirane methyl and urethane) Degree of co-occurrence with regulated VOCs unknown at this time (Potentially include in total VOC MCL until individual MCLs established)

12. Office of Ground Water and Drinking Water 12 Nitrosamines Unregulated CCL 3 (5) - N-nitrosodiethylamine (NDEA) N-nitrosodimethylamine (NDMA) N-nitroso-di-n-propylamine (NDPA) N-nitrosodiphenylamine N-nitrosopyrrolidine (NPYR) Common health effect (carcinogens so likely MCLG could be set at zero) Common analytical method (521) used to measure Common opportunities to reduce formation/expos ure  Modify the disinfection process by adding oxidants (e.g., free chlorine, ozone, other) prior to ammonia application  Manage polymer addition  Use TTHM/HAA5 precursor removal treatment in lieu of chloramines  Consider source water protection as well If regulated as group, could consider total MCL, treatment technique, or combination of two concepts

13. Office of Ground Water and Drinking Water 13 Chlorinated DBPs Regulated - Chloroform Bromodichloromethane Dibromochloromethane Bromoform Monochloroacetic acid Dichloroacetic acid Trichloroacetic acid Monobromoacetic acid Dibromoacetic acid Unregulated 100s of unregulated Chlorinated DBPs Common health endpoint (bladder cancer); Substantial bladder cancer risk remains post-Stage 1 and Stage 2 DBPR (so could set MCLG of zero for bladder cancer risk for chlorinated DBPs as supported by epi studies) Some stakeholders advocated a treatment technique approach to capture many contaminants; may be more applicable to this group - Common treatment technique approach - Remove DBP precursors (total organic carbon or TOC) prior to disinfection to reduce DBP exposure and risk -Common analytical measure/indicator - use TOC (e.g., lower concentration bound and/or percent removal) as a performance measure because it is easy to monitor and allows for treatment choice flexibility (e.g., enhance coagulation, oxidation/filtration, GAC, and/or membranes) to achieve TOC performance metric. Technologies/approaches used to remove DBPs precursors and DBPs could also reduce other contaminants Source water protection could also be used to achieve TOC metric (contributes to removal of organic and nitrogenous material )

14. Office of Ground Water and Drinking Water Potential Groups for Future Consideration Perfluorinated compounds (7)  Common health effects & treatment  Common methods for PFOS &PFOA  Limited occurrence data Organophosphate pesticides (31)  Similar health effects & common treatment  Methods for 4 of 31 compounds  Some measured & modeled occurrence Carbamate pesticides (11)  Similar health effects & common treatment  Methods for 3 of 11 compounds

15. Office of Ground Water and Drinking Water Groups Under Consideration with Issues & Challenges Triazine pesticides (6)  Common treatment & health effects  Ongoing risk assessment Chloroacetanilides (9)  Similar health effects & common treatment  Common analytical methods  Minimal occurrence in UCMR 2 Cyanotoxins (3)  Common source – algal blooms  Range of health effects  Analytical methods are challenging

16. Office of Ground Water and Drinking Water Regulatory Development When proposing/ promulgating drinking water regulations, SDWA requires EPA to:  Establish (non-enforceable) maximum contaminant level goals (MCLG)  Determine the “feasible” level for the enforceable maximum contaminant level (MCL) or if it is not feasible to measure the level of the contaminants, establish a treatment technique (TT) that prevents adverse effects to the extent feasible  Estimate the health risk reduction costs and benefits of alternative MCLs or TTs  Determine if benefits justify the costs at the feasible level  Identify feasible technologies and affordable compliance technologies for small systems

17. Office of Ground Water and Drinking Water Regulatory Development Potential Approaches for Groups Standard approach  individual MCLs and/or a total group MCL Hazard Index &r Relative Potency Factor  Methods for deriving group MCLG and/or MCLs Summation of Cancer Risk  method for assessing benefits of groups of carcinogens Treatment barrier approach  Require treatment in those systems likely to have contaminant group members  Identify monitoring parameters that reflect the removal of the contaminants in the group

18. Office of Ground Water and Drinking Water Next Steps EPA Science Advisory Board consultation Selection of initial contaminant group Begin development of proposed regulation for contaminant group