2013-18954. Update to An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the United States for the Years 1987, 1995, and 2000

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of public comment period and letter peer-review.

SUMMARY:

EPA is announcing a 30-day public comment period for the draft document entitled, Update to An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the United States for the Years 1987, 1995, and 2000, (EPA/600/R-11/005A). EPA also is announcing that Versar, Inc., an EPA contractor for external scientific peer review, will select a group of experts to conduct a letter peer-review of the draft document. The document was prepared by the National Center for Environmental Assessment (NCEA) within EPA's Office of Research and Development.

In November 2006, EPA released the report: An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the United States for the Years 1987, 1995, and 2000, (EPA/600/P-03/002F). That report presented an evaluation of sources and emissions of dioxins, dibenzofurans, and coplanar polychlorinated biphenyls to the air, land, and water of the United States. The inventory suggested that there was a significant reduction in environmental releases of dioxin-like compounds from regulated industrial sources between the years 1987 and 2000, and that the open burning of residential refuse in backyard burn barrels was the largest source in 2000 that could be reliably quantified. This revised draft is an update to the 2006 report and reflects the additional consideration of pre-2006 peer review. This update does not expand the scope of the document beyond the three reference years covered in the 2006 document or earlier drafts: 1987, 1995, and 2000. Changes in the updated report reflect the addition of previously unquantified sources and adjustments to emission factors, for example those used for municipal and medical waste incinerators. The largest source added to the inventory was emissions to air from forest fires, a source previously classified as preliminary and not included in the quantitative inventory. The updated inventory lists the top three air sources in the year 2000 as forest fires, backyard barrel burning of refuse, and medical waste incinerators.

EPA intends to forward the public comments that are submitted in accordance with this notice to Versar to distribute to the external peer-reviewers for their consideration during the letter peer-review. When finalizing the draft document, EPA intends to consider any public comments received in accordance with this notice. EPA is releasing this draft assessment for the purposes of public comment and peer review. This draft assessment is not final as described in EPA's information quality guidelines, and it does not represent and should not be construed to represent Agency policy or views.

The draft document is available via the Internet on the NCEA home page under the Recent Additions and the Data and Publications menus at www.epa.gov/​ncea.

DATES:

The 30-day public comment period begins August 7, 2013, and ends September 6, 2013. Technical comments should be in writing and must be received by EPA by September 6, 2013.

ADDRESSES:

The draft document, Update to An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the United States for the Years 1987, 1995, and 2000, is available primarily via the Internet on the National Center for Environmental Assessment's home page under the Recent Additions and the Data and Publications menus at www.epa.gov/​ncea. A limited number of paper copies are available from the Information Management Team, NCEA; telephone: [phone]; facsimile: 703-347-8691. If you are requesting a paper copy, please provide your name, mailing address, and the document title.

Comments may be submitted electronically via www.regulations.gov,, by mail, by facsimile, or by hand delivery/courier. Please follow the detailed instructions provided in the SUPPLEMENTARY INFORMATION section of this notice.

FOR FURTHER INFORMATION CONTACT:

For information on the public comment period, contact the Office of Environmental Information Docket; telephone: [phone]; facsimile: 202-566-9744; or email: [e-mail].

For technical information, contact Matthew Lorber, NCEA; telephone: [phone]; facsimile: 703-347-8694; or email: [e-mail].

SUPPLEMENTARY INFORMATION:

I. Information About the Document

The purpose of this document is to present a comprehensive inventory and an overview of sources and environmental releases of dioxin-like compounds in the United States. The major identified sources of environmental releases of dioxin-like compounds are grouped into six broad categories: combustion sources, metals smelting, refining and processing sources, chemical manufacturing sources, natural sources, and environmental reservoirs. Estimates of annual releases to land, air, and water are presented for each source category and summarized for reference years 1987, 1995, and 2000. The quantitative results are expressed in terms of the toxicity equivalent (TEQ) of the mixture of polychlorinated dibenzo-p-dioxin (CDD) and polychlorinated dibenzofuran (CDF) compounds present in environmental releases using a procedure sanctioned by the World Health Organization (WHO) in 1998. This TEQ procedure translates the complex mixture of CDDs and CDFs characteristic of environmental releases into an equivalent toxicity concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), the most toxic member of this class of compounds. The total releases under the national inventory for 1987 in g WHO98 TEQDF (grams of dioxin toxic equivalents (TEQs), to include only dioxin and furan congeners (not dioxin-like PCB congeners), and determined using the 1998 World Health Organization's Toxic Equivalency Factors (TEFs)) were 15,000 to air, 2,400 to land, 360 to water, and 36 to products. For 1995, the releases in g WHO98 TEQDF were 3,400 to air, 2,500 to land, 30 to water, and 47 to products. For 2000, the releases in g WHO98 TEQDF were 2,300 to air, 2,300 to land, 28 to water, and 7 to products. This document also provides limited estimates for releases of dioxin-like polychlorinated biphenyls (PCBs).

In comparison to the version of this document released in 2006, estimates of CDD/CDF releases to air increased for all years. The changes reflect the addition of new sources and adjustments to emission factors used for municipal and medical waste incinerators. The largest new source added was forest fires, which was previously classified as preliminary and not included in the quantitative inventory. Based on a number of new studies, it was decided that sufficient data were now available to move this source into the quantitative inventory. The forest fire releases in 2000 were about four times higher than in 1987 and in 1995 (due to more fires) causing a particularly large percent increase in that year. The top three air sources in 2000 were forest fires (730 g WHO98 TEQDF), backyard barrel burning of refuse (600 g WHO98 TEQDF), and medical waste incinerators (400 g WHO98 TEQDF). Other new sources added to the present document were secondary zinc smelters, glass manufacturers, lime kilns, agricultural burning, outdoor wood combustors, aluminum foundries, copper foundries, and septic systems.

II. How to Submit Technical Comments to the Docket at www.regulations.gov

Submit your comments, identified by Docket ID No. EPA-HQ-ORD 2011-0805, by one of the following methods:

• www.regulations.gov: Follow the on-line instructions for submitting comments;
• Email: [e-mail];
• Fax: [phone];
• Mail: Office of Environmental Information (OEI) Docket (Mail Code: 28221T), U.S. Environmental Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460. The telephone number is 202-566-1752. If you provide comments by mail, please submit one unbound original with pages numbered consecutively and three copies of the comments. For attachments, provide an index, number pages consecutively with the comments, and submit an unbound original and three copies; or
• Hand Delivery: The OEI Docket is located in the EPA Headquarters Docket Center, EPA West Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC. The EPA Docket Center's Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is 202-566-1744. Deliveries are only accepted during the docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information. If you provide comments by hand delivery, please submit one unbound original with pages numbered consecutively and three copies of the comments. For attachments, provide an index, number pages consecutively with the comments, and submit an unbound original and three copies.

Instructions: Direct your comments to Docket ID No. EPA-HQ-ORD-2011-0805. Please ensure that your comments are submitted within the specified comment period. Comments received after the closing date will be marked “late,” and may only be considered if time permits. It is EPA's policy to include all comments it receives in the public docket without change and to make the comments available online at www.regulations.gov,, including any personal information provided, unless a comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through www.regulations.gov or email. The www.regulations.gov Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to EPA without going through www.regulations.gov,, your email address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket visit the EPA Docket Center homepage at www.epa.gov/​epahome/​dockets.htm.

Docket: Documents in the docket are listed in the www.regulations.gov index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other materials, such as copyrighted material, are publicly available only in hard copy. Publicly available docket materials are available either electronically at www.regulations.gov or in hard copy at the OEI Docket in the EPA Headquarters Docket Center.

Dated: May 2, 2013.

Debra B. Walsh,

Acting Deputy Director, National Center for Environmental Assessment.