National Association of Water CompaniesOctober 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

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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

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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.

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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 CCL1

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

Determinations1

Final Regulatory Determinations

Proposed Rule (NPDWR1,2)Draft UCMR

Final UCMR

UCMR Monitoring Results

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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.

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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

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•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 HealthOne Method

Common Method Common Control Process

Common Control Process

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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.

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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

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Defining Groups Examples of Broad Groupings

Factors Broad based groupings

SOCs (74) Pesticides (103) IOCs (26) VOCs (45)

Similar Health Effect Endpoints?

Cancer Cholinesterase InhibitionDevelopmental

Cholinesterase InhibitionCancerNeurologicalDevelopmentalTesticular

Uncommon - Various critical effects.

CarcinogensNeurological

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, NF Typically GAC, AOP, Ozone, RO/NF

Typically RO, IX, Coag/Sed, NF

Typically Aeration, GAC

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Groups for Potential Regulatory Development (Near term)

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Carcinogenic VOCsRegulated (8) -

BenzeneCarbon tetrachloride1,2-dichloroethane1,2-dichloropropaneDichloromethaneTetrachloroethyleneTrichloroethyleneVinyl chloride

Unregulated CCL3 (8) -

Aniline Benzyl chloride1,3-butadiene1,1-dichloroethaneNitrobenzeneOxirane 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)

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Nitrosamines

Unregulated CCL 3 (5) -

N-nitrosodiethylamine (NDEA)N-nitrosodimethylamine (NDMA)N-nitroso-di-n-propylamine (NDPA)N-nitrosodiphenylamineN-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/exposure

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

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Chlorinated DBPs Regulated - ChloroformBromodichloromethaneDibromochloromethaneBromoformMonochloroacetic acidDichloroacetic acidTrichloroacetic acidMonobromoacetic acidDibromoacetic acid

Unregulated

100s of unregulatedChlorinated 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 )

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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

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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

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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

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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

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Next Steps

• EPA Science Advisory Board consultation

• Selection of initial contaminant group

• Begin development of proposed regulation for contaminant group