I grew up near a location in Texas in the 1970-1980's where oil well companies would truck in mud from wells, and dump it in a field to dry up and the liquid would run off, the water in the ditches had an oily sheen for miles (would ride my bike around town as far as I could go). I just checked and the field is still there and brown/empty but the company got replaced by a church and it's across the street from a junior high school now (and across a different street from the de facto segregated part of town where most of the African American kids got on the bus I rode to school).