7762 Federal Register / Vol. 76, No. 29 / Friday, February 11, 2011 / Proposed Rules (2) A quorum consists of five is not placed on the Internet, but will be NOEL—no observed effect level members. publicly available in hard copy form. NPDWR—National Primary Drinking Water Regulation * * * * * Publicly available docket materials are available either electronically through NRC—National Research Council Dated: February 2, 2011. PBPK—Physiologically-Based http://www.regulations.gov or in hard Thomas L. Strickland, Pharmacokinetic copy at the Water Docket, EPA/DC, EPA PWS—public water system Assistant Secretary for Fish and Wildlife and West, Room 3334, 1301 Constitution Parks, Department of the Interior. RfD—reference dose Ave., NW., Washington, DC. The Public SDWA—Safe Drinking Water Act Dated: January 18, 2011. Reading Room is open from 8:30 a.m. to UCMR—Unregulated Contaminant Beth G. Pendleton, 4:30 p.m., Monday through Friday, Monitoring Rule μ Regional Forester, USDA—Forest Service. excluding legal holidays. The telephone g—microgram (one-millionth of a gram) U.S.—United States [FR Doc. 2011–2959 Filed 2–10–11; 8:45 am] number for the Public Reading Room is BILLING CODE 3410–11–P; 4310–55–P (202) 566–1744, and the telephone I. General Information number for the EPA Docket Center is (202) 566–2426. Does this action impose any requirements on my public water FOR FURTHER INFORMATION CONTACT: Eric ENVIRONMENTAL PROTECTION system? AGENCY Burneson, Office of Ground Water and Drinking Water, Standards and Risk Today’s action notifies interested 40 CFR Part 141 Management Division, at (202) 564– parties of EPA’s determination to regulate perchlorate, but imposes no [EPA–HQ–OW–2008–0692, EPA–HQ–OW– 5250 or e-mail [email protected]. 2009–0297; FRL–9262–8] For general information contact the EPA requirements on public water systems Safe Drinking Water Hotline at (800) (PWSs). However, this action also RIN 2040–AF08 426–4791 or e-mail: hotline- initiates the process to develop a [email protected]. national primary drinking water Drinking Water: Regulatory regulation (NPDWR) for perchlorate. At SUPPLEMENTARY INFORMATION: Determination on Perchlorate such time as the Agency establishes an AGENCY: Environmental Protection Table of Contents NPDWR, certain PWSs will be required Agency (EPA). I. General Information to take action to comply with the ACTION: Regulatory determination. Does this action impose any requirements regulation in accordance with the on my public water system? schedule specified in the regulation. SUMMARY: This action presents EPA’s (or II. Background II. Background the Agency’s) regulatory determination A. What is the purpose of this action? for perchlorate in accordance with the B. Background on Perchlorate Regulatory A. What is the purpose of this action? Determinations Safe Drinking Water Act (SDWA). The purpose of today’s action is to Specifically, EPA has determined that C. What is EPA’s final regulatory determination on perchlorate and what present EPA’s final determination to perchlorate meets SDWA’s criteria for regulate perchlorate in drinking water, regulating a contaminant—that is, happens next? III. Final Regulatory Determination for the rationale EPA used to make this perchlorate may have an adverse effect Perchlorate regulatory determination, and EPA’s on the health of persons; perchlorate is A. May perchlorate have an adverse effect response to certain key issues raised by known to occur or there is a substantial on the health of persons? commenters on previous Federal likelihood that perchlorate will occur in B. Is perchlorate known to occur or is there Register (FR) notices on the drinking public water systems with a frequency a substantial likelihood that perchlorate water regulatory determination for will occur in public water systems with and at levels of public health concern; perchlorate. (All comments are and in the sole judgment of the a frequency and at levels of public health concern? addressed in a Response to Comments Administrator, regulation of perchlorate document that is available in EPA’s in drinking water systems presents a C. Is there a meaningful opportunity for the reduction of health risks from docket ID No. EPA–HQ–OW–2009–0297 meaningful opportunity for health risk perchlorate for persons served by public for this regulatory determination.) reduction for persons served by public water systems? water systems. Therefore, EPA will D. Regulatory Determination B. Background on Perchlorate initiate the process of proposing a E. Key Commenter Issues Regulatory Determinations national primary drinking water 1. Health Implications of Perchlorate The statutory and regulatory regulation (NPDWR) for perchlorate. Exposure above the RfD background for this action is described DATES: For purposes of judicial review, 2. Other Thyroid Inhibiting Chemicals 3. Perchlorate in Food in detail in the October 10, 2008, FR the regulatory determination is issued as 4. Iodide Nutritional Status notice discussing EPA’s preliminary of February 11, 2011, as provided in 40 5. Physiologically-Based Pharmacokinetic regulatory determination for perchlorate CFR 23.7. (PBPK) Modeling (73 FR 60262; USEPA 2008a). Briefly, ADDRESSES: EPA has established dockets F. Next Steps SDWA section 1412(b)(1)(A), as for this action under Docket ID numbers IV. References amended in 1996, requires EPA to make EPA–HQ–OW–2008–0692 and EPA– Abbreviations and Acronyms a determination whether to regulate at HQ–OW–2009–0297. All documents in least five contaminants from its these dockets are listed on the http:// CBI—confidential business information Contaminant Candidate List (CCL) every www.regulations.gov Web site. Although CCL—Contaminant Candidate List five years. To regulate a contaminant in listed in the index, some information is EPA—U.S. Environmental Protection Agency drinking water, EPA must determine FR—Federal Register not publicly available, e.g., Confidential HRL—health reference level that it meets three criteria: (1) The Business Information or other kg—kilogram contaminant may have an adverse effect information whose disclosure is L—liter on the health of persons; (2) the restricted by statute. Certain other MCL—maximum contaminant level contaminant is known to occur or there material, such as copyrighted material, MRL—Minimum Reporting Limit is a substantial likelihood that the VerDate Mar<15>2010 18:19 Feb 10, 2011 Jkt 223001 PO 00000 Frm 00042 Fmt 4702 Sfmt 4702 E:\FR\FM\11FEP1.SGM 11FEP1 mstockstill on DSKH9S0YB1PROD with PROPOSALS Federal Register / Vol. 76, No. 29 / Friday, February 11, 2011 / Proposed Rules 7763 contaminant will occur in public water additional approaches to analyzing data mandated by the 1996 SDWA systems with a frequency and at levels related to EPA’s perchlorate regulatory Amendments. Specifically, EPA has of public health concern; and (3) in the determination. These additional found that perchlorate may have an sole judgment of the Administrator, comments were sought in an effort to adverse effect on the health of persons, regulation of such contaminant presents ensure consideration of all potential that perchlorate occurs or there is a a meaningful opportunity for health risk options for evaluating whether there is substantial likelihood that perchlorate reduction for persons served by public a meaningful opportunity for human will occur in public water systems with water systems. Once EPA makes a health risk reduction of perchlorate a frequency and at levels of public determination to regulate a contaminant through a NPDWR. EPA stated that the health concern, and that regulation of in drinking water, SDWA requires that alternative analyses presented in this perchlorate in drinking water systems EPA issue a proposed NPDWR within notice could lead the Agency to make a presents a meaningful opportunity for 24 months and a final NPDWR within determination to regulate perchlorate. health risk reduction for persons served 18 months of proposal. EPA received over 6,000 comments on by public water systems. EPA included perchlorate on the first, the August 2009 notice. second, and third CCLs that were EPA has evaluated the approximately A. May perchlorate have an adverse published in the Federal Register on 39,000 public comments received on the effect on the health of persons? March 2, 1998 (63 FR 10273; USEPA May 2007 document, the October 2008 Yes. The perchlorate anion is 1998), February 24, 2005 (70 FR 9071; notice, and August 2009 notice. EPA has biologically significant specifically with USEPA 2005a), and October 8, 2009 (74 prepared a response to comment respect to the functioning of the thyroid FR 51850; USEPA 2009a), respectively. document that addresses the comments gland. Perchlorate can interfere with the On May 1, 2007, EPA published an related to the perchlorate regulatory normal functioning of the thyroid gland update on the Agency’s evaluation of determination (USEPA, 2010a). This by inhibiting the transport of iodide into perchlorate as part of the preliminary response to public comment document, the thyroid, resulting in a deficiency of regulatory determination for 11 other the public comments on the August iodide in the thyroid. Perchlorate CCL 2 contaminants (72 FR 24016; 2009 notice, and supporting materials inhibits (or blocks) iodide transport into USEPA 2007). The Agency did not make are available electronically at http:// the thyroid by chemically competing a preliminary determination for www.regulations.gov (Docket ID No. with iodide, which has a similar shape perchlorate