Diesel fuel is classified as a "diesel range organic" (DRO) for laboratory-testing purposes, and for the purpose of determining cleanup levels. Other DROs include kerosene, heating oil, and jet fuel.
Cleanup levels for diesel range organics in Oklahoma, for example, can vary from 50 mg/kg (milligrams per kilogram) for residential soil, to 2,500 mg/kg for industrial site soil. In Wisconsin, DRO levels of 250 mg/kg are permitted on sites where there is little chance of contaminants migrating into groundwater, and 100 mg/kg on sites where groundwater is at risk. In Washington State, cleanup levels for DROs are as high as 2,000 mg/kg for all sites.
Most states also allow individual sites to set their own cleanup levels based on site-specific assessments. This involves checking whether there are any source-pathway-receptor linkages present. An example would be the contaminated soil (the source) leaching into groundwater, and then into a nearby lake (a pathway), affecting aquatic organisms (receptors). If there are no such linkages present, a site may be permitted to work to higher cleanup levels than the generic levels set by the state.