[Federal Register Volume 67, Number 230 (Friday, November 29, 2002)]
[Notices]
[Pages 71169-71172]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-30261]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-7414-4]


Draft Guidance For Evaluating The Vapor Intrusion to Indoor Air 
Pathway From Groundwater And Soils (Subsurface Vapor Intrusion 
Guidance)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: EPA is publishing a draft guidance addressing the evaluation 
of the ``vapor intrusion pathway.'' The draft guidance is intended to 
provide a tool to help the user conduct a screening evaluation as to 
whether or not the vapor intrusion exposure pathway is complete and, if 
so, whether it poses an unacceptable risk to human health. It is not 
intended to provide recommendations for delineating extent of risk or 
eliminating risk.

DATES: Send your comments to reach us on or before February 27, 2003.

ADDRESSES: Comments may be submitted electronically, by mail, by 
facsimile, or through hand delivery/courier. Send an original and two 
copies of your comments to: OSWER Docket, Environmental Protection 
Agency, Mailcode: 5305-G, 1200 Pennsylvania Avenue, NW, Washington, DC 
20460, Attention Docket ID No. RCRA-2002-0033. Follow the detailed 
instructions as provided in section I.B.

FOR FURTHER INFORMATION CONTACT: For general information, contact the 
RCRA Hotline at (800) 424-9346 (toll free) or call (703) 412-9810; or, 
for hearing impaired, call TDD (800) 553-7672 or TDD (703) 412-3323. 
For more information on specific aspects of this guidance, contact 
Henry Schuver, Office of Solid Waste (5303W), U. S. Environmental 
Protection Agency, Ariel Rios Building, 1200 Pennsylvania Avenue, NW, 
Washington, DC 20460-0002, (703) 308-8656, e-mail address: 
[email protected].

SUPPLEMENTARY INFORMATION:

[[Page 71170]]

I. General Information

A. How Can I Get Copies Of This Document And Other Related Information?

1. Docket
    EPA has established an official public docket for this action under 
Docket ID No. RCRA-2002-0033. The official public docket consists of 
the documents specifically referenced in this action, any public 
comments received, and other information related to this action. 
Although a part of the official docket, the public docket does not 
include Confidential Business Information (CBI) or other information 
whose disclosure is restricted by statute. The official public docket 
is the collection of materials that is available for public viewing at 
the OSWER Docket in the EPA Docket Center, (EPA/DC) EPA West, Room 
B102, 1301 Constitution Ave., NW, Washington, DC. The EPA Docket Center 
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 OSWER 
Docket is 202-566-0207. To view docket materials, you should call in 
advance and make an appointment. You may copy a maximum of 100 pages 
from any regulatory docket at no charge (unless the documents require 
copyright permission). Additional copies cost $0.15 per page.
2. Electronic Access
    You may access this Federal Register document electronically 
through the EPA Internet under the ``Federal Register'' listings at 
http://www.epa.gov/fedrgstr/.
    An electronic version of the public docket is available through 
EPA's electronic public docket and comment system, EPA Dockets. You may 
use EPA Dockets at http://www.epa.gov/edocket/ to submit or view public 
comments, access the index listing of the contents of the official 
public docket, and to access those documents in the public docket that 
are available electronically. Once in the system, select ``search,'' 
then key in the appropriate docket identification number.
    Certain types of information will not be placed in the EPA Dockets. 
Information claimed as CBI and other information whose disclosure is 
restricted by statute, which is not included in the official public 
docket, will not be available for public viewing in EPA's electronic 
public docket. EPA's policy is that copyrighted material will not be 
placed in EPA's electronic public docket but will be available only in 
printed, paper form in the official public docket. When a document is 
selected from the index list in EPA Dockets, the system will identify 
whether the document is available for viewing in EPA's electronic 
public docket. Although not all docket materials may be available 
electronically, you may still access any of the publicly available 
docket materials through the docket facility identified in Unit I.B.
    For public commenters, it is important to note that EPA's policy is 
that public comments, whether submitted electronically or in paper, 
will be made available for public viewing in EPA's electronic public 
docket as EPA receives them and without change, unless the comment 
contains copyrighted material, CBI, or other information whose 
disclosure is restricted by statute. When EPA identifies a comment 
containing copyrighted material, EPA will provide a reference to that 
material in the version of the comment that is placed in EPA's 
electronic public docket. The entire printed comment, including the 
copyrighted material, will be available in the public docket.
    Public comments submitted on computer disks that are mailed or 
delivered to the docket will be transferred to EPA's electronic public 
docket. Public comments that are mailed or delivered to the Docket will 
be scanned and placed in EPA's electronic public docket. Where 
practical, physical objects will be photographed, and the photograph 
will be placed in EPA's electronic public docket along with a brief 
description written by the docket staff.

B. How and To Whom Do I Submit Comments?

    You may submit comments electronically, by mail, by facsimile, or 
through hand delivery/courier. To ensure proper receipt by EPA, 
identify the appropriate docket identification number in the subject 
line on the first page of your comment. Please ensure that your 
comments are submitted within the specified comment period. Comments 
received after the close of the comment period will be marked ``late.'' 
EPA is not required to consider these late comments, but will make 
every effort to do so if time and resources permit. If you wish to 
submit CBI or information that is otherwise protected by statute, 
please follow the instructions in section I.C. Do not use EPA Dockets 
or e-mail to submit CBI or information protected by statute.
1. Electronically
    If you submit an electronic comment as prescribed below, EPA 
recommends that you include your name, mailing address, and an e-mail 
address or other contact information in the body of your comment. Also 
include this contact information on the outside of any disk or CD ROM 
you submit, and in any cover letter accompanying the disk or CD ROM. 
This ensures that you can be identified as the submitter of the comment 
and allows EPA to contact you in case EPA cannot read your comment due 
to technical difficulties or needs further information on the substance 
of your comment. EPA's policy is that EPA will not edit your comment, 
and any identifying or contact information provided in the body of a 
comment will be included as part of the comment that is placed in the 
official public docket, and made available in EPA's electronic public 
docket. 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.
i. EPA Dockets
    Your use of EPA's electronic public docket to submit comments to 
EPA electronically is EPA's preferred method for receiving comments. Go 
directly to EPA Dockets at http://www.epa.gov/edocket, and follow the 
online instructions for submitting comments. To access EPA's electronic 
public docket from the EPA Internet Home Page, select ``Information 
Sources,'' ``Dockets,'' and ``EPA Dockets.'' Once in the system, select 
``search,'' and then key in Docket ID No. RCRA-2002-0033. The system is 
an ``anonymous access'' system, which means EPA will not know your 
identity, e-mail address, or other contact information unless you 
provide it in the body of your comment.
ii. E-mail
    Comments may be sent by electronic mail (e-mail) to [email protected], Attention Docket ID No. RCRA-2002-0033. In 
contrast to EPA's electronic public docket, EPA's e-mail system is not 
an ``anonymous access'' system. If you send an e-mail comment directly 
to the Docket without going through EPA's electronic public docket, 
EPA's e-mail system automatically captures your e-mail address. E-mail 
addresses that are automatically captured by EPA's e-mail system are 
included as part of the comment that is placed in the official public 
docket, and made available in EPA's electronic public docket.

[[Page 71171]]

iii. Disk or CD ROM
    You may submit comments on a disk or CD ROM that you mail to the 
mailing address identified in Unit I.B.2, below. These electronic 
submissions will be accepted in WordPerfect or ASCII file format. Avoid 
the use of special characters and any form of encryption.
2. By Mail
    Send an original and two copies of your comments to: OSWER Docket, 
Environmental Protection Agency, Mailcode: 5305-G, 1200 Pennsylvania 
Avenue, NW, Washington, DC 20460, Attention Docket ID No. RCRA-2002-
0033.
3. By Hand Delivery or Courier
    Deliver your comments to: OSWER Docket, EPA West Building, Room 
B102, 1301 Constitution Avenue, NW, Washington DC, 20004, Attention 
Docket ID No. RCRA-2002-0033. Such deliveries are only accepted during 
the Docket's normal hours of operation as identified in section I.A.1.
4. By Facsimile
    Fax your comments to (703) 603-9234, Attention Docket ID No. RCRA-
2002-0033.

C. How Should I Submit CBI To the Agency?

    Do not submit information that you consider to be CBI 
electronically through EPA's electronic public docket or by e-mail. 
Send or deliver information identified as CBI only to the following 
address: RCRA CBI Document Control Officer, Office of Solid Waste, 
Environmental Protection Agency, Mailcode 5305-W, 1200 Pennsylvania 
Avenue, NW, Washington, DC 20460, Attention Docket ID No. RCRA-2002-
0033. You may claim information that you submit to EPA as CBI by 
marking any part or all of that information as CBI (if you submit CBI 
on disk or CD ROM, mark the outside of the disk or CD ROM as CBI and 
then identify electronically within the disk or CD ROM the specific 
information that is CBI). Information so marked will not be disclosed 
except in accordance with procedures set forth in 40 CFR part 2.
    In addition to one complete version of the comment that includes 
any information claimed as CBI, a copy of the comment that does not 
contain the information claimed as CBI must be submitted for inclusion 
in the public docket and EPA's electronic public docket. If you submit 
the copy that does not contain CBI on disk or CD ROM, mark the outside 
of the disk or CD ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and EPA's 
electronic public docket without prior notice. If you have any 
questions about CBI or the procedures for claiming CBI, please consult 
the person identified in the FOR FURTHER INFORMATION CONTACT section.

D. What Should I Consider as I Prepare My Comments for EPA?

    You may find the following suggestions helpful for preparing your 
comments:
    1. Explain your views as clearly as possible.
    2. Describe any assumptions that you used.
    3. Provide any technical information and/or data you used that 
support your views.
    4. If you estimate potential burden or costs, explain how you 
arrived at your estimate.
    5. Provide specific examples to illustrate your concerns.
    6. Offer alternatives.
    7. Make sure to submit your comments by the comment period deadline 
identified.
    8. To ensure proper receipt by EPA, identify the appropriate docket 
identification number in the subject line on the first page of your 
response. It would also be helpful if you provided the name, date, and 
Federal Register citation related to your comments.

II. Summary

    The draft guidance (Evaluating the Vapor Intrusion to Indoor Air 
Pathway From Groundwater and Soils) examines a single exposure 
pathway--the ``vapor intrusion pathway.'' It is intended to be a 
screening tool to aid users in determining whether a vapor intrusion 
pathway is complete and, if so, whether the completed pathway poses an 
unacceptable risk to human health. A complete pathway means that humans 
are exposed to vapors originating from site contamination. The draft 
guidance begins with simple and generally reasonable conservative 
screening approaches and gradually progresses toward a more complex 
assessment involving increasingly greater use of site-specific data. 
For those sites determined to have an incomplete vapor intrusion 
pathway, further consideration of the current site situation generally 
should not be needed. For those sites determined to have a complete 
pathway, guidance is provided to evaluate whether the pathway does or 
does not pose a potential significant risk to human health.
    This draft guidance is not intended to provide recommendations to 
delineate the extent of risk or eliminate the risk. Its sole purpose is 
to determine if there is a potential for an unacceptable risk. EPA 
generally recommends reevaluation of those sites that are screened-out 
if site conditions or land use changes in a way that might alter a 
decision to screen-out, or other new information suggests greater 
conservatism is appropriate in assessing the vapor intrusion pathway.
    Because this is a draft guidance document, not a regulation, it is 
not subject to the notice and comment requirements of the 
Administrative Procedure Act. Nonetheless, EPA is choosing, in its 
discretion, to solicit comments on the document in the interest of 
developing the most accurate, useful guidance document.

III. At What Sites Are We Currently Suggesting You Use This Guidance?

    EPA suggests that you use this draft guidance at RCRA Corrective 
Action, CERCLA (National Priorities List and Superfund Alternative 
Sites), and Brownfields sites, but, at this time, we do not recommended 
it for use at Subtitle I Underground Storage Tank (UST) sites.
    We recommend that State and Regional UST corrective action programs 
continue to use a risk-based decision making approach as described in 
OSWER Directive 9610.17: Use of Risk-Based Decision Making in UST 
Corrective Action Program to address this pathway at UST sites.

IV. Data Evaluation

    Vapor intrusion is a rapidly developing field of science and policy 
and this draft guidance is intended to aid in evaluating the potential 
for human exposure from this pathway given the state-of-the-science at 
this time. EPA will continue to explore this area in efforts to improve 
the state-of-the-science of this complex exposure pathway. A workgroup 
of EPA and State representatives is currently being organized to 
evaluate this pathway over the next several years. As the state-of-the-
science improves, this guidance will be revised as appropriate. EPA and 
State site managers are encouraged to contact EPA's Office of Solid 
Waste (OSW) to join the workgroup and/or provide the workgroup with 
relevant site information that can be added to the Office of Solid 
Waste and Emergency Response (OSWER) database to facilitate these 
efforts.

V. Will This Draft Guidance Supersede Existing Guidance?

    This draft guidance supersedes the draft RCRA EI Supplemental 
Guidance for Evaluating the Vapor Intrusion to

[[Page 71172]]

Indoor Air Pathway (December 2001). It does not supersede State 
guidance. However, EPA believes that States will find this guidance 
useful and anticipates that States will consider this draft guidance 
when evaluating the vapor intrusion pathway. Additionally, the lead 
regulatory authority for a site may determine that criteria other than 
those recommended in this draft guidance are more appropriate for the 
specific site or area. For example, site-specific indoor air criteria 
may differ from the generic indoor air criteria generally recommended 
in this guidance and, consequently, the corresponding soil gas or 
groundwater screening levels may differ. Also, the site-specific 
relationship between indoor air concentrations and subsurface soil gas 
or groundwater concentrations may differ from that assumed in 
developing this guidance. Therefore, we suggest that the first step 
generally should be to consult with the lead regulatory authority to 
identify the most appropriate approach for evaluation of any potential 
vapor intrusion to indoor air pathway.

VI. When Do We Recommend You Start Using This Draft Guidance?

    EPA recommends that you consider the use of this draft guidance 
now.
    Although the document is still in draft and EPA is requesting 
comment on it, it has gone through extensive internal and inter-agency 
review, and we believe it is a technically sound product. While we hope 
to receive useful comments that will result in improvements when the 
draft is finalized, we believe the document in its current state 
provides the best guidance and information currently available on these 
issues.
    Please recognize that this is a guidance document, not a 
regulation. This document presents current technical and policy 
recommendations of the Office of Solid Waste and Emergency Response, 
based EPA's current understanding of the subsurface vapor intrusion. 
EPA personnel (and of course, states) are free to use and accept other 
technically sound approaches, either on their own initiative, or at the 
suggestion of responsible parties or other interested parties. In 
addition, personnel who use this guidance document are free to modify 
the approach recommended in this guidance. This guidance document does 
not impose any requirements or obligations on EPA, states, or the 
regulated community. Rather, the sources of authority and requirements 
for addressing subsurface vapor intrusion are the relevant statutes and 
regulations (e.g., RCRA, CERCLA and the NCP).

    Dated: November 22, 2002.
Marianne Lamont Horinko,
Assistant Administrator, Office of Solid Waste and Emergency Response.
[FR Doc. 02-30261 Filed 11-27-02; 8:45 am]
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