Regulatory Development and Retrospective Review Tracker

Addition of Subsurface Component to the Hazard Ranking System (HRS)

a.k.a. Subsurface Intrusion HRS Revision (Hazard Ranking System - Vapor Intrusion)

RIN: 2050-AG67 (What's this?)

Docket No.: EPA-HQ-SFUND-2010-1086 (What's this?)

Current Phase: Proposal (What's this?)

The Hazard Ranking System (HRS), required by the Superfund statute, is the primary mechanism used by the EPA to assess the relative threat associated with actual or potential releases of hazardous substances. As a matter of agency policy, those sites that score 28.50 or greater under the HRS are eligible for inclusion on the National Priorities List (NPL).

The NPL is intended primarily to guide the EPA in determining which sites warrant further investigation. A score of 28.50 does not represent a specified level of risk but is a cutoff point that serves as a screening-level indicator of the highest priority releases or threatened releases. The HRS includes four scoring pathways - ground water, surface water, air and soil exposure. Additional pathways have been identified as posing significant threats to human health and the environment that should be considered when evaluating sites for the NPL. One such pathway is subsurface intrusion. Subsurface intrusion occurs when contaminants are released, enter the subsurface environment and move into occupied structures (e.g., residences, workplaces and other buildings) as a gas, vapor or liquid. Over the past decade EPA and state environmental programs have learned significantly more information regarding the risk that this pathway poses to human health. Historically, the EPA's Superfund program has responded to vapor intrusion contamination by two mechanisms: (1) through its emergency response program at sites not on the NPL, or (2) through sites placed on the NPL because of other pathway-related risks. In a May 2010 report, the Government Accountability Office (GAO) concluded that if vapor intrusion sites are not assessed and, if needed, listed on the NPL, some seriously contaminated hazardous waste sites with unacceptable human exposure may not otherwise be cleaned up. Thus, the EPA is working toward a proposed rulemaking to add a new screening component to the HRS that would allow sites with vapor intrusion contamination to be evaluated for placement on the NPL. This addition would enable the HRS to directly consider the human exposure to contaminants that enter building structures through the subsurface environment.

NPRM: Sent to OMB for Regulatory Review02/03/2012
NPRM: EPA Withdrew Rule from Review02/27/2014
NPRM: Sent to OMB for Regulatory Review06/08/2015
NPRM: Received by OMB06/10/2015
NPRM: Regulatory Review Concluded12/21/2015
NPRM: Published in FR02/29/2016
NPRM: Comment Period Open02/29/2016
NPRM: Comment Period Closed04/29/2016
Final Rule: Sent to OMB for Regulatory Review08/31/2016
Final Rule: Received by OMB09/02/2016
Final Rule: Published in FR12/2016 (projected)

Potential Effects

Children's Health
This rule is likely to address an adverse impact on childhood lifestages, including prenatal (via exposure to women of childbearing age). The potential adverse impacts are expected to be due to exposure (i.e., children and/or women of childbearing age are more likely to be highly exposed than other lifestages).

Environmental Justice
This rulemaking involves a topic that is likely to be of particular interest to or have particular impact upon minority, low-income, tribal, and/or other vulnerable populations because:

  • This topic is likely to present an opportunity to address an existing disproportionate impact on vulnerable populations.
  • This topic is likely to result in the collection of information or data that could be used to assess potential impacts on the health or environmental conditions of vulnerable populations.
  • This topic is likely to affect the availability of information to vulnerable populations.

Federal Government - other agencies
Likely to be involved in the implementation of this rule.

Local Governments
Likely to be involved in the implementation of this rule.

Small Entities

Small governments are:

  • Likely to be involved in the implementation of this rule.

State Governments
Likely to be involved in the implementation of this rule.

Tribal Governments
Likely to be involved in the implementation of this rule.

Participate / Learn More Regulatory Review

Some of EPA's rulemakings undergo regulatory review (What's this?), as prescribed by Executive Order 12866 and coordinated by the Office of Management and Budget (OMB). The following list describes which of this rulemaking's stages have completed review and published in the Federal Register, if any, and provides links to the review documents where available. Consult the "Timeline" section of this Web page for the dates of each review.

  • NPRM - This stage of the rulemaking underwent review.
  • Final Rule - This stage of the rulemaking underwent review.
Citations & Authorities

Federal Register Citations

Code of Federal Regulations (CFR) Citation
40 CFR 300

Legal Authority
42 U.S.C. 9601