Three refinery land treatment sites which had ceased applications for 6 months, 9 months, and 6 years previously were sampled to define existing conditions. Samples were collected during a 15-month study period. A considerable variation existed in oil content between the 3 sites. Concentrations greater than background were detected as deep as 45-50 cm at all sites. Average oil content remained relatively constant at each site during the study. Possible contributing factors to apparent lack of degradation were long periods of extremely wet or dry soil, low soil N, and presence of persistent hydrocarbons. Thirteen or more organic priority pollutants were identified at each site; however, only trace quantities were found below the till zone. Metals were immobilized in top 25 cm of soil at all sites. Site 2 supported a lush growth of vegetation while sites 1 and 3 supported little or no vegetative growth. Grasses were more tolerant than tree seedlings when planted in areas having an oil content of 5-6 wt.%.

"October 1984." "EPA-600/2-84-162." "PB85-115822." "Cooperative Agreement No. CR 807936010."