[Federal Register Volume 61, Number 106 (Friday, May 31, 1996)]
[Notices]
[Pages 27349-27351]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-13431]
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ENVIRONMENTAL PROTECTION AGENCY
[FRL-5510-3]
Soil Screening Guidance
AGENCY: Environmental Protection Agency.
ACTION: Notice of availability of Soil Screening Guidance.
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SUMMARY: The U.S. Environmental Protection Agency (EPA) has developed
the Soil Screening Guidance which is now available. This guidance
presents a framework for developing soil screening levels (SSLs),
focusing primarily on a simple methodology for developing site-specific
screening levels, but including generic levels and the opportunity to
do more detailed modeling. The guidance can serve as a tool to expedite
the evaluation of contaminated soils at sites addressed under the
Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA), commonly known as Superfund. The guidance is intended to be
used to screen out areas of sites, exposure pathways, or chemicals of
concern from further consideration, assuming certain conditions are
present, or to determine that further study is warranted at a site. It
is not a rule, does not have the force of a regulation, nor should it
be interpreted to represent cleanup standards for a site.
The Soil Screening Guidance is presented in three documents: (1) a
Quick Reference Fact Sheet, which provides an overview of the
development and use of soil screening levels; (2) a User's Guide, which
provides details for implementing a simple methodology for calculating
site-specific SSLs; and (3) a Technical Background Document (TBD),
which presents generic SSLs and the technical foundation for the
methodology for establishing SSLs. These documents are available from
the National Technical Information Service at the address listed below.
Additional supporting information, including summaries of previous
outreach activities, is available for inspection in the Superfund
Docket at the address listed below.
As part of the development of the Soil Screening Guidance, EPA
conducted extensive outreach and peer review. A major component of that
outreach was providing the document for public comment (59 FR 67706,
December 30, 1994). As a result of comments received during the public
comment period and the independent scientific peer review conducted
concurrently, several changes were made to the guidance. The highlights
of that process are presented below. In addition, EPA has developed a
more detailed Response to Comments on the public review draft and the
independent scientific peer review. This document is also available
from the National Technical Information Service (see below).
DATES: The Soil Screening Guidance was signed by Assistant
Administrator Laws on May 17, 1996 and is now being published by
National Technical Information Service (NTIS).
ADDRESSES: Copies of the draft Soil Screening Guidance may be ordered
[[Page 27350]]
through the NTIS at (703)487-4650 as follows:
Soil Screening Guidance Quick Reference Fact Sheet, 9355.4-14FSA, PB96-
963501, EPA/540/F-95/041
Technical Background Document for Soil Screening Guidance, 9355.4-17A,
PB96-963502, EPA/540/R-95/128
Soil Screening Guidance: User's Guide, 9355.4-23, PB96-963505, EPA/540/
R-96/018
Soil Screening Guidance: Response to Comments, 9355.4-22, PB96-963506,
EPA/540/R-96/019
Members of the public are invited to inspect the docket developed
to support the Soil Screening Guidance at the Superfund Docket, U.S.
Environmental Protection Agency, 1235 Jefferson Davis Highway,
Arlington, Virginia. [Docket Number SSL]. The docket is available for
inspection between 9:00 a.m. and 4:00 p.m., Monday through Friday,
excluding Federal holidays. Appointments to review the docket can be
made by calling (703) 603-9232. The public may copy a maximum of 266
pages from the docket free of charge, however a charge of 15 cents will
be incurred for each additional page, plus a $25.00 administrative fee.
FOR FURTHER INFORMATION CONTACT: The RCRA/Superfund Hotline at (800)
424-9346 (in the Washington, D.C. metropolitan area, (703) 412-9810).
The Telecommunications Device for the Deaf (TDD) Hotline number is
(800) 553-7672 (in the Washington, DC metropolitan area, (703) 412-
3323). You may also contact David Cooper, Office of Emergency and
Remedial Response (5204G), U.S. Environmental Protection Agency, 401 M
Street, S.W., Washington, D.C. 20460, at (703) 603-8763.
SUPPLEMENTARY INFORMATION:
Introduction
The U.S. Environmental Protection Agency (EPA) responds to releases
and threatened releases of hazardous substances under the authority of
the Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA). Regulations governing such responses are found in
the National Oil and Hazardous Substances Pollution Contingency Plan or
NCP. The process for remedy selection in the NCP generally requires
that a remedial investigation be performed to identify the nature and
extent of contamination at National Priorities List (NPL) sites. From
sampling results, as well as site observations obtained in the field,
specific contaminants and exposure pathways of concern are identified
and used in a baseline risk assessment performed to determine whether
remedial action is warranted. (See source documents 1 and 2 listed at
the end of this document.)
Today's Federal Register notice announces the availability of a new
tool which may reduce significantly the time it takes to complete soil
investigations and cleanup actions, as well as improve the consistency
of these actions across the nation. The guidance was written to enhance
the efficiency of remedial investigation/feasibility study (RI/FS) work
at Superfund National Priorities List (NPL) sites. This guidance on
developing soil screening levels is expected to assist site managers in
quickly identifying contaminated soil of potential concern and in
screening out from further consideration those soils that do not
warrant additional study.
The Soil Screening Guidance presents three recommended methods for
developing risk-based, soil screening levels, but emphasizes a simple,
site-specific approach. The formulae and exposure assumptions used to
develop the screening levels have been taken from the Risk Assessment
Guidance for Superfund 1,2 and have been widely accepted in the
Superfund program for a number of years. These levels are then compared
to on-site soil contaminant levels. Areas of a site which fall below
the screening levels may be eliminated from further assessment. Areas
above the screening levels generally warrant further evaluation of the
potential risks that may be posed by site contaminants to determine the
need for response action. While the guidance is recommended for use as
a screening tool to determine if further study of specific portions of
a site is warranted, the levels should not be interpreted to represent
cleanup standards for a site.
Background
In 1993 EPA's Office of Emergency and Remedial Response (OERR)
developed a draft fact sheet entitled: ``Interim Soil Screening Level
Guidance.'' This guidance discussed the development and use of risk-
based Soil Screening Levels (SSLs) for 30 common Superfund soil
contaminants. The document was issued on September 30, 1993, to provide
the basis for discussion of the SSL project with stakeholders and is
available for review as background information in the Superfund Docket.
The effort to develop such a guidance was requested under both the EPA
Administrator's June 19, 1991, ``30-Day Study,'' and the more recent
Superfund Administrative Improvements Initiatives announced by the
Deputy Administrator on June 23, 1993. This guidance was subsequently
revised and expanded to become the ``Soil Screening Guidance,'' dated
December 1994. This guidance was provided to the public for comment (59
FR 67706) and submitted to independent scientific peer review. As a
result of comments received in this process, we made several changes to
the document. Some of the most significant comments are highlighted
here. The Response to Comments provides a more in-depth discussion of
these changes and many other, less significant technical changes.
(1) Guidance needs to be more user friendly. EPA has modified the
presentation of the guidance because many people commented that it was
not clear how to implement the guidance. The Soil Screening Guidance
has been reorganized into a ``user's guide'' to provide more useful
information on how to develop simple site-specific screening levels and
compare those to contaminant concentrations found at sites.
(2) Generic SSLs will be misused. The generic SSLs are still part
of the framework, but they have been moved to the Technical Background
Document in an effort to prevent their misuse. They now appear in a
section which discusses the technical assumptions that go into the
development of those numbers.
(3) Generic SSLs are too conservative. Another impetus for moving
the generic levels to the TBD is concern that the generic levels were
too conservative. One of the modeling inputs leading to this
conservatism is the assumption of an infinite source of contamination.
To address this concern, the new guidance provides an opportunity use
site-specific information to develop a conservative estimate of the
volume of contamination at the site.
(4) Sampling strategy was based on an assumption that is not
appropriate for all sites. One of the peer reviewers commented that the
approach for sampling the site to determine the contaminant
concentrations was dependent on the assumption of a log-normal
distribution of contamination that may not actually occur at the site.
That approach has been replaced by a strategy that includes adequate
sampling of surface soil in the exposure area, compositing of some
samples to reduce laboratory costs, and comparison of the screening
level with the maximum of the composite samples from each exposure
area. The strategy balances the desire for a statistically based
sampling strategy with the need to control the number of samples and
the laboratory costs.
[[Page 27351]]
(5) Non-residential land uses need to be considered. EPA received
from many stakeholders that SSLs should be developed for other land
uses such as industrial or recreational. EPA agrees in principle that
other land uses need to be considered. However, as a first step in the
development of screening levels EPA chose to focus on residential use
because there is more agreement in the risk assessment community about
the types of relevant pathways and assumptions appropriate for modeling
residential exposures. Several of the Superfund reforms announced in
October 1995 address non-residential land uses and should provide
information which could be used to expand the soil screening guidance
to other land uses.
Goals
EPA's goal in developing this guidance is to provide a tool which
can be used to expedite the evaluation of contaminated soils at sites
addressed under CERCLA. The guidance is intended to be used to screen
out areas of sites, exposure pathways, or chemicals of concern from
further consideration or to determine that further study is warranted
at a site. It may be used where assumptions made in developing the tool
(e.g., residential land use, no ecological concerns) are consistent
with conditions found at specific sites.
This guidance is not intended to be, and should not be construed as
a rule. Use of the guidance is not legally binding either on EPA staff
or on other parties; rather it is intended to be a tool available for
use under appropriate site-specific conditions. NPL sites do not all
meet the conditions necessary for its use, consequently, EPA does not
expect this tool to be useful at all NPL sites. EPA staff applying the
guidance have discretion to follow it or diverge from it as site-
specific conditions may warrant, and each site-specific action will be
explained on its own record.
Please contact individuals and offices listed in the sections of
this notice entitled ``Addresses'' and ``For Further Information
Contact'' to learn more about the Soil Screening Guidance.
Source Documents
1. U.S. EPA. 1989. Risk Assessment Guidance for Superfund:
Volume 1: Human Health Evaluation Manual, Part A, Interim Final.
EPA/540/1-89/002. Office of Emergency and Remedial Response,
Washington D.C. NTIS PB90-155581/CCE.
2. U.S. EPA. 1991. Risk Assessment Guidance for Superfund,
Volume 1: Human Health Evaluation Manual (Part B, Development of
Risk-Based Preliminary Remediation Goals). Publication 9285.7-01B.
Office of Emergency and Remedial Response, Washington, D.C. NTIS
PB92-963333.
Dated: May 17, 1996.
Elliott P. Laws,
Assistant Administrator.
[FR Doc. 96-13431 Filed 5-30-96; 8:45 am]
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