HEER Research Reports

HEER Office research reports can be accessed below. Refer also to presentations and reports posted under the HEER Office Webinars for further information.


The report and fact sheet posted below summarize the results of a detailed, HEER Office study of arsenic in the sediment and biota of Waiākea Pond, in Hilo, Hawaiʻi. High levels of arsenic were identified in sediment throughout the pond. The arsenic is believed to be associated with waste from a canec plant and a sugar mill that operated on the mauka (south) edges of the pond in the early 1900s. Although well above natural background, the arsenic was found to be tightly bound to naturally-occurring iron in the sediment and not significantly toxic. Normal contact with sediment in the pond does not pose a risk to park users. Levels of arsenic in samples of fish and crabs collected from the pond were similar to naturally-occurring levels of arsenic in the same species of fish and crabs from other areas of the islands. The arsenic does not pose a health risk to people who catch and consume fish and crabs from the pond. Although arsenic in the sediment does not pose a significant health risk to park users who periodically come in contact with the sediment, washing hands before eating and maintaining good hygiene in general is recommended to minimize exposure. Contact Roger Brewer or Dr. Diana Felton of the HEER Office in Pearl City for additional information (1-808-586-4249).


The below presentation on “Large Volume Purge (LVP)” methods for the collection of subslab vapor samples was originally give to the Hawaiʻi Association of Environmental Professionals (HAEP) by Roger Brewer of the HEER Office on June 28, 2017. The slides and recorded presentation were subsequently modified to incorporate comments and questions received during the original presentation. A discussion of “LVP” sampling methods will be added to Section 7 of the HEER Office Technical Guidance Manual later this year. Comments and suggestions are welcome and should be sent to [email protected].

A draft update to Section 7 of the HEER Office TGM that incorporates LVP sampling methods is also posted below. Please send comments and edits to Roger Brewer ([email protected]) by October 31, 2017. The document, including figure locations, will be formatted for posting to the TGM web site after incorporation of final edits. The discussion of LVP methods will be updated in the future based on input and experience with LVP methods in the field.

The field report for the LVP study carried out in 2016 by the HEER Office is available for download from the link below. The report provides detailed diagrams of the equipment and methods used to collect both passive vapor samples and LVP vapor samples at the study site. Refer also to presentations on active and passive soil vapor sampling methods posted on this web page in March 2015.


This HEER Office field study evaluates the nature of random variability within and between co-located, discrete soil samples and discusses implications for the continued use of discrete soil (and sediment) sample data for final, decision making purposes as part of an environmental investigation. Hundreds of co-located discrete samples were tested at three sites known respectively to be contaminated with arsenic, lead and PCBs. Part 1 of the study presents the field study design and the resulting data. Part 2 of the study discusses implications for use of discrete data for site characterization and risk assessment purposes.

Included below are links to the 2015 field study report (separate data files provided in Excel), PowerPoint slides and recorded presentations for Parts 1 and 2 of the study presented in 2016, a two-part paper on the study published in January 2017 and a summary of the field study presented to USEPA in August 2017. Refer to the “Discrete Soil Sample Variability Field Study” folder on the HEER Office YouTube channel for recorded presentations.

A brief comparison of discrete vs Multi Increment sampling methods is included in the presentations. Refer to the four-part, Technical Guidance Manual series posted to the HEER Office webinar webpage in June 2017 for a detailed overview of DU-MIS investigation methods, including: 1) Systematic Planning of Site Investigations, 2) Designation of Decision Units, 3) Sampling theory and characterization of DUs (discrete vs MIS) and 4) DU-MIS field implementation.


This HEER Office field study evaluates the chemistry of vapors from fresh fuels and aged petroleum releases to soil and groundwater. Dozens of soil vapor samples were collected from multiple sites in Hawaiʻi and tested using a suite of analytical methods.

The study focuses on the carbon range makeup of the “TPH” component of vapors and the relative vapor intrusion risk posed by “TPH” vs “BTEXN.” The study concludes that the mixture of aromatic and in particular aliphatic compounds that make up the “TPH” component of vapors can still pose significant vapor intrusion risks even though concentrations of benzene and other individual aromatics in vapors are well below levels of concern. Nonetheless, shallow LNAPL is required under most scenarios for a significant risk to be present. The link a paper published on the field study is also provided. The original paper published in 2013 was edited and re-published in 2014.

An audio recording of a presentation given to the USEPA in 2013 is posted below. Slides are not included with the recording.

Field Investigation of the Chemistry and Toxicity of TPH in Petroleum Vapors: Implications for Potential Vapor Intrusion Hazards (2012)


Provides links to download additional HEER Office technical reports, memorandums and fact sheets associated with the Technical Guidance Manual otherwise not provided on this page.

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