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1 **Summary of Comments and Discussion U.S. Environmental Protection Agency**  **Preliminary Regulatory Determinations for**  **the Third Contaminant Candidate List STAKEHOLDER MEETING**  Washington Plaza Hotel 10 Thomas Circle NW Washington, DC 20005 June 16 , 20 11 **Welcome and Opening Remarks** Pamela Barr, U

. S
. EPA

 Every five ye ars, EPA is required to make decisions on at least five contaminants on the Contaminant Candidate List (CCL) . The next set of determinations is due in final form in the summer of 2013. EPA has made no decisions at this point, and some information is still being collected and updated.  EPA welcomes comments from stakeholders during this process. George Hallberg, Cadmus (F acilitator )

 The meeting objectives are as follows: o Provide an overview of the Safe Drinking Water Act (SDWA) regulatory processes with a specific focus on the regulatory determinations for unregulated contaminants listed on the Contaminant Candid ate List . o Discuss the approach and data sources being used to evaluate potential contaminants for Regulatory Determinations 3. o Share and discuss health effects and occurrence information for specific contaminants being evaluated for Regulatory Determinatio ns 3. o Solicit input/feedback from stakeholders on contaminants and information under consideration.  After each presentation, stakeholders are invited to ask questions or provide comments. EPA is particularl y interested in information regarding additional sources of data.**DRAFT**

2 **Overview of the Various SDWA Regulatory Processes, the Contaminant (CCL) and Regulatory Deter**  **minations Process** Wynne Miller, U.S. EPA

 This presentation covered the following topics: o An overview of SDWA regulatory processes. o An overview of SDWA statutory criteria for Regulatory

Determinations and potential outcomes. o The history

and timeline for previous CCL and Regulatory Determination efforts. **Overview of Approach to Evaluate Potential Contaminants for Regulatory Determinations** Zeno Bain, U.S. EPA

 This presentation covered the following topics: o The approach used to screen and identify potential contaminants for Regulatory D eterminations. o The approach and information considered in evaluating contaminants against the three SDWA statutory

criteria for proceeding with a drinking water regulation . o A list of potential c ontaminants being evaluated for Regulatory Determinations 3. o An introduction to the Drinking Water Strategy .  A participant made recommendations related to stakeholder access and involvement. This meeting was advertised in a Federal Register (FR) notice two weeks in advance and potential participants were given five business days to pre
- register. The participant recommended that EPA allow for written comments to be submitted after the meeting, when participants and others have had an opportunity to review th e materials in more detail . The participant also suggested that EPA provide notice of stakeholder opportunities farther in advance and perhaps hold more frequent meetings to increase stakeholder access . EPA explained that this meeting was planned so it wou ld be convenient for attendees of the American Water Works Association’s 130th Annual Conference & Exposition (ACE), which was held in Washington, D.C. on June 11 to 16, 2011. EPA will try

to allow more time for registration in the future. In addition, EPA noted that potential meeting participants should not hesitate to contact EPA even after a registration deadline has passed . The deadline was established to get a tentative headcount, so an appropriate meeting facility could be reserved . EPA would encourage all to attend the meetings as long as space allows.  A participant asked if EPA will make meeting materials available in PDF format. EPA does plan to make the presentations available on the Agency website.**DRAFT**

3 **Contaminants Being Evaluated for Regulatory Determinations 3 (Part 1)**  Zeno Bain, U.S. EPA

 This presentation provided background, health effects , and occurrence information for the following contaminants: o Nitrosamines (considered as a group) :  N - nitrosodimethylamine (NDMA).  N - nitrosodiethylamine (NDEA).  N - nitrosodi
- n - prop yl amine (NDPA).  N - nitrosopy

rrolidine (NPYR).  N - nitrosodiphenylamine (NDPhA). o Chlorate.

 A participant asked if EPA plans to revisit the cancer slope factors for all carcinogens based on the 2005 guidelines. EPA will follow the 2005 guidelines for all mutagenic carcinogens and revise the cancer slope factors accordingl y. EPA explained that f etuses, infants and children are especially sensitive to the nitrosamine compounds , so it is important to apply

the Age Dependent Adjustment Factor (ADAF) . In addition, early exposure may

lead to increased risk of cancer later in life, and additive risk should also be taken into consideration.  EPA clarified that the infant formula powder data (presented on slide 29) only represents the concentration in dry

powder . B ecause NDMA levels in formula have decreased to below detection limits, the primary source of exposure to infants drinking formula would be the water used to reconstitute the formula.  A participant asked about the advantag es of regulating contaminants as a group. EPA explained that it may

be more efficient to regulate contaminants as a group; EPA can develop one regulation instead of several individual regulations. Regulating contaminants as a group may also be more efficient for public water s ys tems, because they can plan treatment strategies based on the group of contaminants rather than adjusting their practices several times in response to several individual regulations. Also, the group approach may

address additive risk , as well as potentially providing public health protection from other related contaminants.  A participant asked how EPA plans to address situations where the Minimum Reporting Level (MRL) is greater than the Health Reference L evel (HRL). EPA noted that th ere is ongoing research in this area; however, at this time EPA must work with the approved anal ytical methods. If EPA did decide to regulate nitrosamines, for example, the Agency would need to consider constraints on analy tical feasibility

posed b y the MRL when establishing the Maximum Contaminant L evel ( MCL). There are a number of regulated compounds where the MCLhas been limited by analy tical feasibility . EPA would also need to perform extrapolations to estimate the occurrence of the contaminants at the lower value.  A participant asked if EPA is anticipating a move to advanced treatment methods that forgo chloramines in order to reduce nitrosamine formation . EPA responded that this issue must be investigated in more detail. However, EPA’s data set does include some**DRAFT**

4 sy stems using chlorine with higher nitrosami ne occurrence levels. EPA added that one option might be to control organic matter prior to chloramination .  A participant asked for more information on the Maximum Contaminant Level Goal (MCL G) for carcinogens. EPA explained that, prior to the 2005 regulations, all carcinogens received a MCL G of zero. However , future Regulatory D eterminations may look at this more closely . I f there is a demonstrated mode of action with a quantitative precursor effect, then the reference dose, not cancer, would be the contro lling effect. EPA mentioned chloroform as one example of this situation.  A participant suggested that, if regulations constrain chloramine use, cost may be a less important factor than operational difficulties. Depending on the MCL chosen , operational diff iculties could preclude the use of chloramines entirely . Constraining the use of chloramines could lead to increased issues with other DBPs and impact how water sy stems treat for disinfection. EPA acknowledged that this is an ongoing area of discussion and study .  A participant described a model that is under development for perchlorate and chlorate. Under the worst
- case scenario for perchlorate, months of storage time could occur before levels of concern are exceeded. However, for chlorate, the model indic ates that as little as two or three day s of storage time could lead to levels higher than the WHO benchmark. The participant added that EPA may have to choose which contaminants and issues will drive decision making because there may be some risk tradeoffs .  A participant asked about the sources of occurrence data for contaminants on the CCL , and particularly

why the CWSS was noted as an occurrence data source . EPA clarified that Community

Water Sy stem Survey

(CWSS) data include some occurrence data from large s ys tems, as well as data on treatment methods and general trends. The participant recommended that EPA provide more specific information on data sources. Other participants noted that EPA prepares detailed support documents for the Regulatory D etermination process that provide this ty pe of information. EPA agreed that data sources will be described in detail in the support documents.  EPA clarified that all seven nitrosamines discussed in the presentations, including the two included in the second cycle o f the Unregulated Contaminant Monitoring Rule (UCMR2 ) but not in the CCL 3, c ould be included in the group. **Contaminants Being Evaluated for Regulatory Determinations 3 (Part 2)** Melissa Simic, U.S. EPA

 This presentation provided background, health effects , and occurrence information for the following contaminants: o Moly bdenum. o Strontium. o Vanadium.  A participant asked about the essential nutrient levels for moly bdenum. For adults, including pregnant women, the amount is 45
- 50 micrograms per day (per the Institute of Medicine, 2001). Essential nutrient levels for infants are based on amounts in maternal milk and can also be found in the Institute of Medicine document. EPA added that this is**DRAFT**

5 still under investigation as new data become available; if EPA were to develop a new reference dose and HRL , they would likel y be higher than they are currently .  A participant asked about the relative contributions of natural and industrial sources for IOCs in areas with levels near the HRL. EPA has looked at this is sue, and it can’t be easily resolved in a broad sense (though i n local areas it can sometimes be sorted out) . H owever, for naturall y- occurring elements like strontium, there is a natural contribution to almost all water samples. EPA added that, under SDWA, the source of the contaminant does not matter . Instead, EPA only considers whether a contaminant occurs in drinking water at frequencies and levels of concern.  A participant asked if EPA will develop its own risk assessment for vanadium. EPA responded that the Integrated Risk Information System ( IRIS ) currently does not have a risk assessment for soluble vanadium salts. However, additional data are becoming available from new human
- based studies. EPA has also updated its literature search and has compiled a new database that is more comprehensive than the Agency for Toxic Substances and Disease Registry (ATSDR) toxicological profile . Vanadium may receive a revised Office of Water risk assessment value, based on the new data.  A participant asked about the process of updating risk assessments. EPA reminded all of the participants that no decisions or determinations have been made at this time. In addition, any new risk assessments prepared for these contaminants is subject to peer review. Some occurrence data (such as final data from UCMR2), are not yet available. EPA has performed a new literature search for the contaminants with outdated risk assessments. EPA has identified new studies and is working on updating risk assessments, but (per the process discusse d in the introductory presentation) this is an ongoing effort. **Contaminants Being Evaluated for Regulatory Determinations 3 (Part 3)** Zeno Bain, U.S. EPA

 This presentation provided background, health effects , and occurrence information for the following contaminants: o 1,1,1,2 - Tetrachloroethane. o 1,2,3 - Trichloropropane. o 1,3 - Dinitrobenzene. o 1,4 - Dioxane. o Methyl Tertiary

Butyl Ether (MTBE). o Nitrobenzene. o PFOS and PFOA. o RDX.  A participant noted the importance of considering PFOS and PFOA separately , based on their individual chemical properties. The participant noted that industry has been partnering with EPA on a stewardship program that aims to phase out PFOA emissions and p roduct content over the next several years. The participant also suggested that occurrence data for PFOA is not robust or representative enough for a Regulatory D etermination at this time.**DRAFT**

6  EPA clarified that when there are no detects above the HRL , detect s above half the HRL are presented in the slides . If there are no detects above half the HRL , EPA presents the total number of detects.  A participant noted that three chemicals discu ssed in this presentation had zero , two, or three detects in the UCMR1 and UCMR2 data, and that this wo uld seem to indicate a negative Regulatory

D etermination. The participant added that obtaining additional representative data is not an issue when UCMR results are available. **Contaminants Being Evaluated for Regulatory Determ inations 3 (Part 4)**  Guy Cole, U.S. EPA

 This presentation provided background, health effects , and occurrence information for the following contaminants: o Dimethoate. o Disulfoton. o Diuron. o Molinate. o Terbufos and Terbufos Sulfone.  A participant asked about th e PBT Profiler. EPA explained that the model places half
lives (and other predicted properties) into bins or categories , which result s in some repetition of reported half
- life values . **Contaminants Being Evaluated for Regulatory Determinations 3 (Part 5**  **)** Ali Arvanaghi, U.S. EPA

 This presentation provided background, health effects , and occurrence information for the following contaminants: o Acetochlor and its ESA and OA d egradates. o Alachlor ESA and OA d egradates (alachor is currently regulated). o Metolachlo r and its ESA and OA d egradates.  EPA provided some additional information about the Pesticide Data Progr am (PDP). PDP is a U.S. Department of Agriculture (USDA) program that is best known for monitoring pesticide residue on foods. However, it also includes some finished water data .  A participant asked if the studies of contaminant degradates considered the occurrence of the parent compound. EPA noted that while data on parent compounds were available in some reports , the published reports did not alway s pre sent information on their co
occurrence . EPA did not have the “raw” data from these studies and could only note what was stated in the reports. S ome older U.S. Geological Survey (USGS ) papers have observed that degradates are more widel y detected than the parent compounds, because the parent has degraded.  A participant expressed support for a positive Regulatory D etermination on this set of contaminants. Some states have listed waters as “impaired” because they contain these contaminants. The parti cipant added that industry has been working with EPA to collect**DRAFT**

7 data and derive reference doses. Another participant noted that there have been limited detections for these contaminants, suggesting that they should not be regulated.  A participant asked whe ther EPA might consider pesticides as a group or as subgroups. EPA recapped the four grouping criteria with regard to their applicability to pesticides. First, there are no common anal ytical methods for the broader groups of “pesticides, ” though there are potential opportunities for research in this area. Second, only the more advanced or expensive treatment options are common to the group. Third, occurrence data are limited, especially regarding co
- occurrence. Finall y, onl y small subgroups have common heal th endpoints. EPA has not ruled out considering these or other contaminants as groups, but it appears unlikely that EPA will be able to formulate a broad pesticide group. **Additional Questions** 

 A participant asked why the hormones included in the CCL 3 we re not selected for further consideration. EPA responded that occurrence data were too limited. However, several hormones are proposed for UCMR3, which should provide more comprehensive data.  A participant asked under what conditions EPA considers earl y li fe stages to be sensitive subpopulations. EPA explained that, as more studies are conducted and more data become available, earl y l ife stages will likely be considered sensitive subpopulations for more contaminants. For example, recent strontium studies have indicated that neonates and adults respond differently across a range of doses. EPA will also be considering earl y life stages when it applies the Age Dependant Adjustment Factor. In addition, the 1996 SDWA amendments require EPA to consider sensitive s ub
- populations when developing or revising regulations. Because of this, EPA take s sensitive sub
- populations into account during the Six
- Year Review process as well .  A participant asked if EPA is considering a different review schedule for the nitrosamines and other grouped contaminants. EPA responded that no decisions have been made at this time, but the nitrosamines will be considered as a possible group during the Regulatory Determination process. At this point, only the carcinogenic volatile organic contaminants (VOCs) have been slated for review for regulation as a group . **Next Steps and Closing Remarks** Pamela Barr, U.S. EPA

 EPA asked participants to submit additional inform ation by e - mail to Zeno Bain at bain.zeno@epa.gov .  EPA will develop draft determinations by the summer of 2 012 in order to meet the final deadline of summer 2013. EPA does not anticipate that it wi ll be able to hold any more public meetings, but there will be a public comment period for the draft determinations and EPA will consider these comments as it develops the final determinations.