Environmental Hazard Evaluation and Environmental Action Levels

An Environmental Hazard Evaluation (EHE) is the link between site investigation activities and response actions carried out to address hazards posed by the presence of contaminated soil and groundwater.

Environmental Action Levels (EALs) are concentrations of contaminants in soil, soil gas, and groundwater that are used in decision making throughout the EHE process. This page provides information on EHE guidance and supplemental models in Microsoft Excel; periodic updates to the EALs and associated guidance; and additional resources for related information. For additional information, contact Roger Brewer of HEER at [email protected].


Evaluation of Environmental Hazards at Sites With Contaminated Soil and Groundwater

Draft Spring 2024 updates to the Environmental Hazard Evaluation (EHE) guidance and related information can be downloaded from the below links. Comments are welcome and should be submitted to Roger Brewer of the HEER Office by May 1, 2024 ([email protected]).

Summary of Spring 2024 Updates
A summary of updates and changes to previous editions of the EHE guidance is provided in Volume 2, Appendix 9. The updates primarily reflect relatively revisions to physiochemical constants used by the U.S. Environmental Protection Agency (EPA) to develop EPA’s 2023 Regional Screening Levels (RSLs). The updates also reflect revision of USEPA toxicity factors for carbon range compounds associated with Total Petroleum Hydrocarbons (TPH).

The document Evaluation of Environmental Hazards at Sites With Contaminated Soil and Groundwater (the “EHE Guidance”) is a technical report that can be used to expedite the identification of potential environmental hazards at sites with contaminated soil and groundwater as well as assist in the cleanup and redevelopment of these properties.

Important Notes:

  • The EHE Guidance should be used in conjunction with the HEER Office’s Technical Guidance Manual, which provides information on site investigation design and implementation as well as a an overview of the EHE process, and other HEER Office guidance.
  • The EALs refer to EPA RSLs as one of a number of sources for soil, water and air screening levels. As stated in the EPA RSL Guidance User’s Manual, the EPA RSLs cannot be used as a stand-alone tool to evaluate the need for additional actions at contaminated sites. The EPA RSLs only address direct exposure of humans to contaminants in soil. Other potential environmental hazards, including leaching and impacts to groundwater, vapor intrusion and gross contamination, have been incorporated into the EALs to allow for a more comprehensive review of contaminated properties without the need to assess these issues separately.

  • HDOH EAL Surfer (Draft Spring 2024)
    • The EAL Surfer is a searchable, electronic version of the EAL lookup tables.
    • Use of the EAL Surfer to screen site data and expedite preparation of EHE reports is highly recommended.
    • The EAL Surfer automatically generates a summary page that can be included in reports. The EAL Surfer also includes a glossary, a summary of information on the chemical selected and an overview of options for more advanced evaluations of environmental hazards.
    • If you have trouble using the pulldown menus on the EAL Surfer then remove the write protection (under the Tools menu). The password to unprotect the EAL Surfer worksheets is EAL. The EAL Surfer is updated on a regular basis. Check this post periodically to ensure that you have the most up-to-date edition available.
  • Comparison of TPH Action Levels to Water Sample Data
    Use of TPH Action Levels (HIDOH Draft March 2024)
    Petroleum Forensics (Newfields Jan 2024)

    Fuel Study Laboratory Reports
    Hawaii DOH Fuel Study (Newfields 2022)
    Hawaii DOH Fuel Study Raw Data (Newfields Oct 2022)

    JP-5 Fuel Study
    A laboratory-based study of the chemistry and toxicity of JP-5 jet fuel was carried out by HDOH in 2023 as part of an Exposure Assessment report related to the 2021 contamination of the Joint Base Pearl Harbor Hickam drinking water system. The study included detailed testing of the BTEXMN and aliphatic carbon range makeup of neat JP-5 jet fuel, vapors emitted from the fuel dissolved-phase hydrocarbons in direct contact with the fuel. Links to the Exposure Assessment report and associated laboratory reports are posted below.

    Note that TPH action levels for middle distillate fuels presented in the updated EAL guidance replace and take precedence over earlier, interim action levels for JP-5 fuel presented in an April 2022 HDOH Technical Memorandum: Recommended Risk-Based Drinking Water Action Levels for Total Petroleum Hydrocarbons (TPH) Associated with Releases of JP-5 Jet Fuel (last revised 02/12/2022). Laboratory data for JP-5 fuel were included as part of the 2024 update to TPH EALs for middle distillate fuels.

    Anticipated updates to TPH action levels for JP-5 contaminated drinking water based on revisions to USEPA toxicity factors for specific carbon ranges are discussed in the HDOH report Exposure Assessment: November 2021 Release of JP-5 Jet Fuel into the Joint Base Pearl Harbor Hickam and Connected Drinking Water Systems (HDOH 2023). Example TPH action levels based on revisions to the USEPA toxicity factors and presented in that document are similar to TPH action levels for middle distillate fuels in general presented in the draft EAL update. A copy of the Exposure Assessment report and associated technical information can be downloaded from the HDOH Red Hill Water Information webpage: https://health.hawaii.gov/about/red-hill-water-information/

    JP-5 Exposure Reports
    JP-5 Exposure Report (HIDOH 2023)
    JP-5 Laboratory Report (Newfields 2022)
    JP-5 Water-Fuel Study Summary Tables (Newfields July 2023)


    Related guidance and information is posted below. Refer also to the HEER Office Technical Guidance webpage.

    PFASs EALs and Total PFAS Risk (April 2024)

    The April 2024 memorandum posted below presents soil, groundwater, indoor air and soil vapor Environmental Action Levels (EALs) for screening of sites contaminated with per- and polyfluoroalkyl substances (PFASs). The action levels represent a supplement to the HEER Office guidance document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (“EHE Guidance;” HIDOH 2024 and updates). An Excel-based EAL Surfer of electronic lookup tables specific to PFASs is available for download from the link below.

    The previous edition of the PFAS EAL guidance was updated in to include action levels for additional PFASs compounds (total 25 compounds). A method for calculation of “Total PFAS Risk” based on “Total Oxidizable Precursors (TOPs)” sample processing methods and data for “Total Organic Fluorine (TOF)” is also added to the guidance. The approach allows consideration of PFAS precursor compounds in assessment of risk and design of remedial actions without the need to identify and assess each precursor compound separately. An Excel spreadsheet is included to assist in calculation of a cumulative Hazard Index for PFASs reported for a sample. A Fact Sheet is provided to summarize the basis of the Total PFAS Risk approach and guide use of the accompanying Excel spreadsheet.

    February 10, 2024: The Total PFAS Calculator was revised to correct Drinking Water and Soil Action Levels for PFBS and PFPeS.

    The PFASs EALs will be periodically updated in the future as new information is obtained. Comments and suggestions for future edits are welcome and should be submitted to Roger Brewer of the HEER Office at any time.

    A recorded webinar entitled “Per- and Poly-Fluoroalkyl Substances – MCLs, MCLGs and Updates to ‘“Hawaii’s” PFAS Guidance” is posted to the HEER Office webinar webpage.

    Also visit the HEER page PER- AND POLYFLUOROALKYL SUBSTANCES (PFASs) for more information on these substances in the environment.

    Per- and Polyfluoroalkyl Substances (PFAS)

    EHE EAL/ESL Training Webinar (Nov 21, 2017)

    read more and download presentation
    Below are links to PowerPoint slides and a recording of a webinar entitled Screening for Environmental Hazards at Sites with Contaminated Soil and Groundwater, presented by Roger Brewer of the HEER Office on November 21, 2017. The webinar discusses the upfront incorporation of Environmental Hazard Evaluation (EHE) concepts in Decision Unit and Multi Increment Sample site investigation methods (refer to HEER Office DU-MIS webinars posted on TGM webpage). Potential environmental hazards posed by different suites of chemicals and the development of soil, water and air action (screening) levels applicable to each concern are then reviewed. The webinar concludes with a discussion of the incorporation of EHE and EAL/ESL approaches in traditional, environmental risk assessments.

    Fall 2014

    Spring 2012 Updates

    Field Investigation of the Chemistry and Toxicity of TPH in Petroleum Vapors: Implications for Potential Vapor Intrusion Hazards. Revised Dec 2012

    Fall 2011 Update

    The Tier 1 EALs were updated in Fall 2011. A summary of updates and HDOH comments can be downloaded from the links below.

    Note that the Fall 2011 edition was revised in January 2012 to correct an error in the TPH action levels.

    June 2010 Update:

  • Related Technical Documents

The case studies presented in the document link below highlight the use of Total Petroleum Hydrocarbon (TPH) data for soil, soil vapor, groundwater, surface water and ambient air associated with the risk-based investigation, remediation and long-term management of petroleum releases. The case studies in large reflect current, HDOH guidance and were prepared with input from multiple, outside state and federal regulators as well as private consultants and experts associated with the petroleum industry. The primary authors, Roger Brewer of the HDOH and Manivannan (Mani) Nagaiah of Langan Engineering & Environmental Services, are also active members of the TPH Risk Working Group of the Interstate Technology & Regulatory Council (ITRC) and acknowledge important contributions to the document from many of the ITRC team members. The HDOH case studies will be referenced in the ITRC TPH Risk document for examples of the site-specific use of TPH data in a variety of petroleum-release scenarios (anticipated publication early 2019).

HDOH, 2018. Collection and Use of Total Petroleum Hydrocarbon Data for the Risk-Based Evaluation of Petroleum Releases, Example Case Studies (October 2018): R. Brewer, M. Nagaiah and R. Keller, authors. Hawaiʻi Department of Health, Hazard Evaluation and Emergency Response Office. Honolulu, Hawaiʻi.


A similarly named guidance document, referred to as the Tropical Pacific Edition, has been prepared for use in the Commonwealth of the Northern Mariana Islands and Guam (formerly referred to as the Pacific Basin Edition). The Tropical Pacific Edition of the EHE guidance incorporates the EPA Regional Screening Level models. Similarities and differences between this guidance and the Hawaiʻi EHE Guidance and the EPA RSL guidance are discussed in Volume 1 of the document.

Contact us at (808) 586-4249 for any questions.