Potential Approaches for Addressing Groups of Contaminants Under the Safe Drinking Water Act

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. 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 2

3. Statutory Requirements for the Various Drinking Water Regulatory Processes (1996 SDWA Amendments) 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. 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. 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. 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. 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. 3 3

4. Opportunities within SDWA Processes to Consider Contaminant Group(s) Draft CCL1 Preliminary Regulatory Determinations1 Final CCL Proposed Rule (NPDWR1,2) Final Regulatory Determinations Draft UCMR Final UCMR Final Rule (NPDWR) Six Year Review of Existing NPDWRs No further action if make decision to not to regulate (may develop health advisory). UCMR Monitoring Results 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. 4 4

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. Examples of Currently Regulated Groups Common Health One Method Common Health One Method Common Method Common Control Process Common Control Process • 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). • 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

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. 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 Groups Initially Identified

9. Defining Groups Examples of Broad Groupings

10. Groups for Potential Regulatory Development (Near term)

11. Carcinogenic VOCs

12. Nitrosamines

13. Chlorinated DBPs

14. 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. 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. 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. 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. Next Steps • EPA Science Advisory Board consultation • Selection of initial contaminant group • Begin development of proposed regulation for contaminant group