State and federal cleanup levels for petroleum hydrocarbons in soil: State of the states and implications for the future

ABSTRACT

The Association for Environmental Health and Sciences Foundation has been collecting information on state-by-state petroleum cleanup levels (CULs) for soil since 1990, with the most recent survey in 2012. These data form the basis for this analysis, including a comparison of the CULs to U.S. Environmental Protection Agency (USEPA) regulatory values. The results illustrate the evolving complexity of state regulatory approaches to petroleum mixtures; benzene, toluene, ethylbenzene, and xylenes; and carcinogenic polycyclic aromatic hydrocarbons, as well as the use of multiple exposure scenarios and pathways to regulate petroleum in soil. Different fractionation approaches in use by various states and the USEPA are discussed, their strengths and limitations are reviewed, and their implications for site CULs are evaluated. Because of an increasing array of scenarios and pathways, CUL ranges have widened over time. As the regulatory environment for petroleum releases becomes more complex, it is increasingly important to develop a conceptual site model for fate, transport, land use assumptions, and exposure pathways at petroleum-contaminated sites to enable selection of the most appropriate CULs available.

KEYWORDS:

• cleanup level
• fraction
• petroleum
• regulation
• soil

Funding

The preparation of this article was supported in part by a grant from the AEHS Foundation and the American Petroleum Institute. The opinions expressed in this article are those of the authors and not necessarily those of the State of Washington Department of Ecology.

Notes

¹ The DTSC guidance on evaluating TPH is no longer active (https://www.dtsc.ca.gov/assessingrisk/humanrisk2.cfm). In DTSC's Human Health Risk Assessment guidance (HHRA Note 3; DTSC 2014), they recommend use of the EPA RSLs for the majority of the chemicals, including TPH. As a result, EPA RSLs were used in this study. Additional approaches are recommended in DTSC's Preliminary Endangerment Assessment Guidance Manual (DTSC 2013) but were not included in this study.

² It appears that Maine and Montana may have adopted the fractionation approach developed by Massachusetts.