EHE Guidance – Tropical Pacific Edition

EHE Guidance – Pacific Basin Edition

“Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater – Tropical Pacific Edition” is a technical report with accompanying electronic lookup tables and Environmental Screening Levels (ESLs) prepared for use in tropical areas outside of Hawaiʻi, including Guam and the Commonwealth of the Northern Mariana Islands. This report was renamed in 2016 from “Pacific Basin Edition” to “Tropical Pacific Edition” to emphasize the intended applicability of the included ESLs to tropical climate zones. The vapor intrusion screening levels, for example, assume warm, year-round temperatures and minimal to no heating of buildings. More conservative screening levels would be required for colder climates. Use of the guidance for environmental investigations should be discussed ahead of time with the overseeing regulatory agency. The most recent updates to the guidance are dated Fall 2017. A summary of updates to the 2016 edition of the guidance is provided in the links below and in Volume 2, Appendix 8.

The Tropical Pacific Edition of the EHE guidance follows similar guidance prepared by the Hawaiʻi Department of Health (“the Hawaiʻi Edition”). A comparison of the two documents is provided in Volume 1 of the Tropical Pacific Edition document. In particular, the Hawaiʻi Edition makes default allowances for low-quality groundwater in pre-designated coastal zones, especially in highly developed and/or brackish, coastal areas of the Hawaiian Islands. By Hawaiʻi state law, drinking water standards are not applicable to these areas. Such default allowances may not be acceptable in other areas, however, where all groundwater may be considered by default to be a potential source of drinking water that warrants a higher degree of protection unless otherwise approved by the overseeing, regulatory agency (e.g., in Guam).

The Tropical Pacific Edition of the EHE guidance closely follows toxicity factors, water standards and other guidance published by the U.S. EPA. Within the limitations noted in Volume 1 of the guidance, this helps make the Tropical Pacific Edition of the EHE guidance more useful across a broad geographic area.

The guidance can be downloaded from the links provided below. Comments, suggestions and questions are welcome at any time and should be provided to the contact persons noted below.

Attn: Roger C. Brewer
Office of Hazard Evaluation and Emergency Response
Hawaiʻi State Department of Health
2385 Waimano Home Rd
Pearl City, Hawaiʻi 96782
E-mail: [email protected]
Telephone: +1 (808) 586-4249

Guam Environmental Protection Agency
Administration Building
17-3304 Mariner Avenue
Tiyan, Guam 96913
Telephone: +1 (671) 475-1658/59

Northern Mariana Islands
Ray Masga
Commonwealth of the Northern Mariana Islands
Division of Environmental Quality
Saipan, MP 96950-1304
Telephone: +1 (670) 664-8500
E-mail: [email protected]

Tropical Pacific Environmental Hazard Evaluation (EHE) Guidance – Updated Fall 2017

The Tropical Pacific EHE and ESL guidance was updated in October 2017. The updates primarily reflect relatively revisions to physiochemical constants used to develop the 2017 U.S. EPA Regional Screening Levels and new information on TPH risk. Refer to Appendix 8 in Volume 2 and the Updates worksheet of the ESL Surfer for details. Revisions to action levels for common contaminants are not expected to significantly alter the results of past site investigations or site investigations currently underway.

The EHE guidance should be used in conjunction with HEER Office Technical Guidance Manual, which provides information on site investigation design and implementation as well as a an overview of the EHE process. Note that the ESLs refer to U.S. EPA Regional Screening Levels (RSLs) as one of numerous sources for soil, water and air screening levels. As stated in the U.S. EPA’s RSLs User’s Guide, the RSLs cannot be used as a stand-alone tool to evaluate the need for additional actions at contaminated sites. The 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 ESLs to allow for a more comprehensive review of contaminated properties without the need to assess these issues separately.

The EHE guidance and associated supplemental material can be downloaded from the below links. Try using another browser if you have problems downloading files with the browser you are currently using. The ESL Surfer file has an “Updates” page with a summary of updates. Comments and suggestions from the general public are welcome at any time. Updates will be posted to this website and notification sent to persons on the EAL/ESL mailing list. Workshops to present and discuss the ESLs will also be held periodically. To provide comments or be included on the mailing list for updates and workshop announcements, contact Roger Brewer of the HEER Office at [email protected].

TPESLs Updates Fall 2017 (rev 11 6 17)
Volume 1 (TPESLs Fall 2017 rev 11 6 17)
Volume 2 Appendix 1 (TPH ESLs Fall 2017 rev 11 6 17)
EHE Vol 2 App 2-8 (TPESLs 2017)

Supplemental Models and Guidance

The Environmental Screening Level (ESL) Surfer is a searchable, electronic version of the ESL lookup tables. Use of the ESL Surfer to screen site data and expedite preparation of EHE reports is highly recommended. The Surfer automatically generates a summary page that can be included in reports. The 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. Download the Surfer from the link below then double click on the file to open the program. If you have trouble using the pulldown menus on the Surfer then remove the write protection (under the Tools menu). The password to unprotect the Surfer worksheets is “ESL”. The ESL Surfer is revised on a regular basis to reflect updates to the lookup tables in the ESL document. Please check this webpage periodically to ensure that you have the most up-to-date edition available.

Note – The write-protect password for all Excel file worksheets is “ESL”.

Tier 2 Direct Exposure (HDOH 2017)
Appendix 1 Tables (TPESL Fall 2017rev 11 6 17)
ESL Surfer (TPESL Fall 2017rev 11 6 17)
Vapor Unit Conversion (HDOH 2017)
BTLM Spreadsheet (HDOH 2017)
Batch Test Guidance (Fall 2017)


HDOH, 2017, Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater – Tropical Pacific Edition (Fall 2017): prepared by Hawaiʻi Department of Health, Hazard Evaluation and Emergency Response Office.