Developing Cleanup Endpoints for Inland Oil Spills

Abstract

ABSTRACT Achieving consensus on cleanup endpoints for inland oil spills can be difficult. They tend to be more stringent than those applied to spills in the marine environment and often require more intensive cleanup methods with the risk of increased ecological impacts. There are limited data on which to evaluate net environmental benefit considerations, weighing the consequences between ecological versus human-use priorities. Inland habitats often lack some of the dynamic physical processes (such as waves and tidal fluctuations) that can speed the rate of natural removal of oil residues. The direct human uses of inland habitats, such as for drinking water, recreation, industrial use, and irrigation, require a higher degree of treatment than may be required in the marine environment to avoid human health and socio-economic impacts. Spills in close proximity to where people live, work, or recreate also often require treatment to a higher level. Inland spills can affect smaller water bodies where there are slower rates of dilution and degradation. There may be large-scale differences in water levels during the response, causing oil to be stranded well above normal levels where it can pose hazards to wildlife as well as humans using these areas. Many states perform risk assessments and develop endpoints for sediment quality and/or surface and groundwater guidelines that must be met as part of the remediation phase after the emergency response is completed. Case studies are used to illustrate these issues. Guidelines are provided for developing appropriate cleanup endpoints for inland oil spills and selection of appropriate treatment methods to reach them.