EPA Grant Number: R827015-01-0
Title: Development of Relevant Ecological Screening Criteria (RESC) for
Petroleum Hydrocarbon-Contaminated Exploration and Production Sites
Investigators: Roman Lanno, Will Focht, Anne Cross
Institutions: Oklahoma State University
EPA Project Officer: Bala Krishnan
Project Period: July 1, 2000 to June 30, 2001 (N/C Ext. to December 31,
2001)
Project Amount: $117,463
Research Category: Ecorisk assessment
Faced with the task of assessing cleanup options based on ecological risk-based on ecological risk-based criteria at thousands of small upstream sites, oil and gas producers are in need of a streamlined rationale for assessing ecotoxicological risk at these sites. The development of a risk based corrective action (RBCA) approach for the protection of ecological resources provides a mechanism for site-specific ecological risk assessment (ASTM 1999). However, a lack of toxicity data for soil organisms and relevant ecological screening criteria (RESC) for conducting ecological risk assessments may result in the use of default parameters and the derivation of overly conservative protection limits, resulting in unnecessary cleanup expense. The proposed research will use crude oil-contaminated soil from the Tall Grass Prairie Preserve, Pawhuska, OK, that vary in hydrocarbon content to conduct laboratory-based toxicity tests with microbes, soil invertebrates, and plants. Toxicity tests will be conducted with standard soil test invertebrates (earthworm Eisenia fetida), non-standard soil test invertebrates (e.g., enchytraeids, collembola, isopods), native prairie plant species, and soil microbial assessments consisting of examining community structure and N-mineralization. This will result in an expanded database from which RESC can be derived. Exposure assessment will consist of determining total petroleum hydrocarbons (TPH) by standard techniques (IR and GC/MS) and by estimating bioavailable petroleum hydrocarbons (BPH) using solid-phase microextraction (SPME) fibers. Results of the laboratory bioassays will be used to generate RESC for plants, soil invertebrates, and microbes exposed to hydrocarbons in prairie grassland soils. Development of dose-response relationships using bioavailable petroleum hydrocarbons and organism responses would allow the applicability of the results of this study to a broader range of contaminated sites, not just prairie habitats.