The Sinclair Refinery site is a former refinery in Wellsville, Allegany County, New York. The site is composed of a 90-acre refinery area, 10-acre landfill area, and 14-acre offsite tank farm. From 1901 to 1958, the site was used to process Pennsylvania grade crude oil until a fire in 1958 halted operations. Currently, some private companies and the State University of New York occupy the site. A 1981 site inspection revealed that debris from the eroding landfill area has washed into and contaminated the Genesee River. The ROD addresses OU2, remediation of the remaining contaminated areas at the site located within the 90-acre refinery area and the offsite tank farm including the contaminated ground water beneath the refinery. The primary contaminants of concern affecting the soil and ground water are VOCs including benzene and xylenes, semi-volatile compounds including naphthalene and nitrobenzene, and metals including arsenic and lead. The selected remedial action for the site is included.