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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].
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A summary of updates and changes to previous editions of the EHE guidance is provided in Volume 2, Appendix 9. Revisions to action levels are not expected to significantly alter the results of past site investigations or site investigations currently underway.
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.
The most current edition of the EHE Guidance is dated Fall 2017. The updates primarily reflect relatively minor revisions to physiochemical constants used by the U.S. Environmental Protection Agency (EPA) to develop EPA’s 2017 Regional Screening Levels (RSLs) and new information on risks posed by total petroleum hydrocarbons (TPH).
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.
Hawaiʻi Department of Health, 2017, Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (Fall 2017): Hawaiʻi Department of Health, Hazard Evaluation and Emergency Response Office.
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.
Related guidance and information is posted below. Refer also to the HEER Office Technical Guidance webpage.
EALs FOR PFASs (April 2021)
The April 2021 memorandum posted below presents soil and groundwater 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 2017 and updates). An Excel-based EAL Surfer of electronic lookup tables specific to PFASs is available for download from the link below. (Note – The original April 2021 was revised 4/19/21 to insert Table 4b.)
Action levels for PFBS- were updated to reflect a revised oral Reference Dose toxicity factor for PFBS- published by the USEPA (USEPA 2021). This resulted in a reduction of tapwater and soil direct exposure and leaching action levels for PFBS-. Default, acute aquatic toxicity action levels for PFHxS-, PFBA-, PFHxA-, PFUnDA- and PFDoDA- and associated soil leaching action levels revised to correct error in Fall 2020 tables. The updates affect soil and groundwater action levels for these chemicals at sites where groundwater is not a source of drinking water and is situated >150m from a body of surface water (refer to Summary Table B). Action levels for other site scenarios and other PFASs were not affected. The updated action levels replace and take precedence over action levels presented in the previous, December 2020 technical memorandum.
The PFASs EALs will be periodically updated in the future as new information is obtained. Comments and suggestions for future edits are welcome and may be submitted to Roger Brewer of the HEER Office ([email protected]) at any time.
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.
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.
EHE GUIDANCE – TROPICAL PACIFIC EDITION
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 Editionof 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.