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August 9, 2000 Executive Summary of Arsenic in Drinking Water Stakeholder MeetingBackground On August 9, 2000, the U.S. Environmental Protection Agency (EPA) held a one-day stakeholders meeting in Reno, Nevada, to present elements of the June 22, 2000 proposal and to answer questions about the proposed Arsenic and Clarifications to Compliance and New Source Contaminants in Drinking Water Rule. Over 140 people attended in person and about 40 people joined by phone. Welcome by James Taft, the Acting Director for the Standards and Risk Management Division. While EPA will write down and consider views expressed at the meeting, he encouraged people to submit comments in writing to the Docket for the rulemaking record. Although EPA missed the statutory date for the proposal, the Office of Water is striving to meet the statutory deadline to issue the final rule by January 1, 2001. EPA agrees with the National Academy of Sciences that existing research supports lowering the current standard of 50 parts per billion (ppb). EPA's risk characterization identified the level which would be no more risky than one excess death in 10,000 persons. Although the feasible level (measurable and treatable) is 3 ppb, EPA is proposing 5 ppb and also asking for comments on 3 ppb, 10 ppb, and 20 ppb. Mr. Taft recognized that people have concerns about the data and science supporting the health effects assessment as well as EPA's analysis of the costs and benefits. Asking for comment on so many concentrations is unusual and reflects uncertainties about the health effects. Although EPA does not accept the drinking water supply industry cost estimate, the Agency is continuing to meet with industry to discuss it. Although some believe that EPA has already chosen the final MCL, that is not true. EPA is very interested in getting the points of view of the attendees and other commenters. Regulatory History and SDWA Statutory Process. The presentation highlighted preamble material found on pages 38892-38896, the discussion of risk characterization on page 38902, and sections XIII and XIV. EPA has a statutory requirement to identify how it reconciled inconsistencies in scientific data used in the proposal, and people can comment on how well EPA met this requirement. EPA is adding comments to the rulemaking docket that people submitted after the pre-publication copy of the proposal went on the arsenic web page on May 25, 2000. That added twenty-eight days to the "official" 90-day comment period, which started the date of publication, June 22, 2000, and ends September 20, 2000. Over 95% of the nation's school children are served by CWSs. The current arsenic MCL does not apply to the 20,000 non-transient, non-community water systems (NTNCWSs). The proposal estimates that less than one half of one percent of all students would be exposed to arsenic above 5 µg/L if NTNCWSs continue to be unregulated. However, depending on the comments received, NTNCWSs could be fully regulated in the final rule. The Regulatory Impact Analysis in the docket is also available electronically and on the arsenic web page. The Small Business Advocacy Review panel report is in the docket. Although EPA found no socioeconomic bias or disproportionate risks to children, the Agency invites comment on these positions and submission of any peer-reviewed data on early life exposure risks. The Health Risk Reduction and Cost Analysis is section XIII of the preamble.
MCLG Development, Risk Characterization, and Health Advisory. EPA calculated a theoretical noncarcinogenic MCLG of 3-30 ppb (using the method in the Final Rule for Phase V on pgs. 31781-31784 of the July 17, 1992 Federal Register (57 FR 31776)). The presentation covered a review of the 1996 proposed carcinogen risk assessment guidelines, exposure, NRC report, on-going peer review of health effects section of the proposal. The proposed health advisory would be available soon after the final rule is issued, to give guidance to the public prior to the effect dates 3-5 years after promulgation.
Treatment Decision Tree, Costs, Variances, Affordability. EPA derived treatment costs from 3 models, the W/W Cost Model, the Water Model, and the Very Small Systems model to model flows between 200 and 0.015 million gallons a day. In some instances, the models were modified to be more reflective of current market conditions based on comments from stakeholders. For membrane technologies, EPA used published operating cost data. Results of case studies support EPA's assumption that residuals will not be subject to regulation as hazardous waste. Since we proposed small system compliance technologies, we did not list variance technologies. EPA requests comment on its affordability criteria and approach to measure the cumulative cost of rules
Benefits, Proposed MCL Options, and NODA. Uncertainties in shape of the dose-response curve, use of grouped exposure data, selenium and arsenic levels in diet could overestimate risk. Survival rate applied to Taiwan and incomplete identification of health effects besides bladder cancer underestimate risk in U.S. The Notice of Data Availability for lung cancer risks will be available within a month in order that commenters can undertand how it affects the proposed rule. Excess deaths in Taiwan from lung cancer associated with arsenic appear to be about the same as the arsenic-related deaths from bladder cancer.
National Occurrence Estimates. From the 25-State database EPA derived system, regional, and national estimates for community water systems and NTNCWSs. Analysis of data from the U.S. Geological Survey showed no change over time in well measurements although draw down could affect results. The attendees raised no concerns with these analyses or the underlying rationale. Analytical Methods and Development of the PQL. EPA is proposing to remove approval of inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analytical methods for arsenic, because the detection limits are too high to support the new MCL options. Laboratory capacity appears to be sufficient at the practical quantitation level of 3 ppb with acceptance limits of ± 30%. No one mentioned any concerns after the presentation. Monitoring and Implementation Issues. Stakeholders have already asked if rounding to the nearest 0.001 mg/L must follow the illustrated "even/odd" protocol that would round 0.0055 mg/L to 0.006 mg/L and 0.0045 mg/L to 0.004 mg/L. Applications for monitoring waivers need to provide data below the new MCL, which can be done using existing test methods. EPA is taking comments on the draft compliance guidance available at http://www.epa.gov/safewater/ars/implement.html.
Consumer Confidence Report, Public Notification, and Next Steps. The existing consumer confidence rule (CCR) requires providing the public with health information if arsenic is detected between 25 and 50 ppb. If arsenic is detected, the annual report must provide the MCL, highest detected level, range, and likely source of contamination. The proposal will require that reports provide health effects language starting in the report covering 2001 for detections above the new MCL, which will not be effective until three to five years after the final rule is promulgated, depending on system size. The existing public notification, with reporting arsenic MCL violations within 14 days, will continue as late as May 6, 2002 in States with primacy. Tier 2 will require notice within 30 days for the new, lower MCL violations and NTNCWSs exceeding the new MCL effective 3-5 years after the final MCL is issued. People can call the Safe Drinking Water Hotline to ask for copies of the proposal and/or electronic (if available) or hard copies of the technical support documents for occurrence, analytical methods, treatment, risk, and the regulatory impact analysis. Final
Agenda Meeting times are shown in Pacific Daylight Time (PDT)
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