[Federal Register Volume 77, Number 131 (Monday, July 9, 2012)]
[Proposed Rules]
[Pages 40318-40319]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-16692]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 300
[EPA-HQ-SFUND-2011-0647; FRL-9697-5]
RIN 2050-AD75
Availability of Addendum to Documentation Supporting the Proposal
of the Leeds Metal Site to the National Priorities List
AGENCY: Environmental Protection Agency.
ACTION: Proposed rule; notice of data availability.
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SUMMARY: This Notice provides an opportunity to comment on the EPA's
revised Hazard Ranking System (HRS) scoring for the Leeds Metal site in
Leeds, Maine. The site was proposed to the National Priorities List
(NPL) on September 16, 2011.
DATES: Comments must be submitted (postmarked) on or before August 8,
2012.
ADDRESSES: Submit your comments, identified by Docket number EPA-HQ-
SFUND-2011-0647, by one of the following methods:
www.regulations.gov: Follow the online instructions for
submitting comments.
Email: superfund.docket@epa.gov.
Mail: Mail comments (no facsimiles or tapes) to Docket
Coordinator, Headquarters; U.S. Environmental Protection Agency; CERCLA
Docket Office; (Mail Code 5305T); 1200 Pennsylvania Avenue NW.;
Washington, DC 20460.
Hand Delivery or Express Mail: Send comments (no
facsimiles or tapes) to Docket Coordinator, Headquarters; U.S.
Environmental Protection Agency; CERCLA Docket Office; 1301
Constitution Avenue NW.; EPA West, Room 3334, Washington, DC 20004.
Such deliveries are accepted only during the Docket's normal hours of
operation (8:30 a.m. to 4:30 p.m., Monday through Friday, excluding
Federal holidays).
Instructions: Direct your comments to Docket number EPA-HQ-SFUND-
2011-0647. The EPA's policy is that all comments received will be
included in the public Docket without change and may be made available
online at www.regulations.gov, including any personal information
provided, unless the 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; that means the 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 the 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, the 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 the EPA cannot read your comment due to technical
difficulties and cannot contact you for clarification, the 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.
Docket: All 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 material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in www.regulations.gov or in hard copy at the EPA Headquarters CERCLA
Docket Office, 1301 Constitution Avenue NW.; EPA West, Room 3334,
Washington, DC 20004. The 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, and the
telephone number for the EPA Headquarters CERCLA Docket Office is (202)
566-0276. Comments must be submitted to the EPA Headquarters as
detailed at the beginning of this preamble in the ``Addresses''
section. Please note that the mailing addresses differ according to
method of delivery. There are two different addresses that depend on
whether comments are sent by express mail or by postal mail.
FOR FURTHER INFORMATION CONTACT: Terry Jeng, phone: (703) 603-8852,
email: jeng.terry@epa.gov, Site Assessment and Remedy Decisions Branch,
Assessment and Remediation Division, Office of Superfund Remediation
and Technology Innovation (Mail Code 5204P), U.S. Environmental
Protection Agency, 1200 Pennsylvania Avenue NW., Washington, DC 20460.
[[Page 40319]]
SUPPLEMENTARY INFORMATION:
Site Scoring Information
The Leeds Metal HRS site score at the time of proposal to the
National Priorities List was based on an observed release to ground
water of tetrachloroethylene (PCE) and trichloroethylene (TCE)
attributable to waste piles and contaminated soil at the Leeds Metal
facility resulting in a likelihood of release factor category value of
550. The waste characteristics factor category value of 56 at proposal
was based on a hazardous waste quantity for TCE of 10,000, a toxicity
value for TCE of 10,000 and a mobility factor for TCE of 1. The TCE
toxicity value was based on the most recent health effects data review
by the EPA at the time of proposal (76 FR 57702, September 16, 2011).
The targets factor category value was 176.4 at proposal based on
populations relying on contaminated drinking water supplies with either
PCE or TCE levels above HRS health-based benchmarks (i.e., Level I
concentrations). Seven residential wells were documented to contain
Level I concentrations of TCE based on the lowest benchmark value for
TCE for ground water. One of these seven wells was also documented to
contain Level I concentrations of PCE based on the lowest benchmark
value for TCE for ground water. The lowest benchmark for TCE was the
cancer slope screening concentration (0.21 [mu]g/L) and the lowest
benchmark for PCE was also the cancer slope screening concentration
(1.6 [mu]g/L) based on the most recent health effects data review by
the EPA at the time of proposal. Seventeen residents were documented to
drink the water from the seven wells with Level I concentrations. The
likelihood of release, waste characteristics and targets factor
category values resulted in a ground water migration pathway score of
100.00 and an HRS site score of 50.00 at proposal (see 76 FR 57702,
September 16, 2011).
Background on TCE and PCE Benchmarks and Toxicity Values
Following the September 16, 2011, proposal of the Leeds Metal site
to the National Priorities List, the toxicity and benchmark values for
PCE and TCE used in HRS scoring were updated to reflect the EPA's most
recent health effects evaluations on these two substances. The
revisions for these two substances were made available to the public on
March 31, 2012 (see http://www.epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm). Among the factors that changed, which affect the
toxicity and drinking water benchmarks, are the oral reference dose
(RfD) and the oral cancer slope factors. Using the HRS methods for
determining toxicity and benchmarks (see HRS Sections 2.4.1.1 and
2.5.2), the toxicity for TCE has changed from 10,000 to 1,000, however
the toxicity for PCE remains the same at 100. When recalculating the
drinking water benchmarks for TCE, the lowest TCE benchmark value for
drinking water remains based on the cancer slope screening
concentrations; the recalculated TCE benchmark value changes from 0.21
[mu]g/L to 1.0 [mu]g/L. The lowest drinking water benchmark for PCE
changes from 1.6 [mu]g/L to 5.0 [mu]g/L.
Background on Targets Factor Category Value
Based on the changes to the TCE and PCE benchmarks, two drinking
water wells within the 4-mile target distance limit have TCE
concentrations above its lowest benchmark and no well had PCE
concentrations above its lowest benchmark. Thus, now only two wells and
the population using these wells are considered Level I.
The Leeds Metal site's potential population factor value has been
updated to reflect those people utilizing drinking water not currently
found to be contaminated due to this site, but that for HRS purposes
are considered potentially threatened. The basic information supporting
the calculation of this value was presented in Reference 11 which was
available to the public at the time of NPL proposal; however, the
factor value was not included in the HRS documentation record at that
time. Populations utilizing either public or private water supplies
have been incorporated into the HRS evaluation based on the information
in Reference 11 to the HRS documentation record at proposal, which
relied on 1990 and 2000 census data and 2009 population data from the
State of Maine. The impact on eligibility of the site to qualify for
the NPL has been confirmed based on the most current information,
including updated census data (2010) and 2012 well use information.
New Benchmarks, Toxicities, Targets and Site Score
Due to the revised toxicity values and the update to the evaluation
of the potential targets, the likelihood of release factor category
value remains 550, the same as at proposal; the waste characteristics
factor category value, which was 100 at proposal, drops to 56 due to
the changes in the Level I wells; the potential population factor
value, the applicable targets factor category value, changes from 220
to 176.4. As a result of these updates, the HRS ground water migration
pathway score changes from 100.00 to 65.85; and the HRS site score
changes from 50.00 to 32.92. The NPL listing decision is not changed by
this updated information and scoring.
The updated HRS scoring documentation is available in
www.regulations.gov under docket number EPA-HQ-SFUND-2011-0647.
List of Subjects in 40 CFR 300
Environmental protection, Air pollution control, Chemicals,
Hazardous substances, Hazardous waste, Intergovernmental relations,
Natural resources, Oil pollution, Penalties, Reporting and
recordkeeping requirements, Superfund, Water pollution control, Water
supply.
Dated: June 29, 2012.
James E. Woolford,
Director, Office of Superfund Remediation and Technology Innovation.
[FR Doc. 2012-16692 Filed 7-6-12; 8:45 am]
BILLING CODE 6560-50-P