The Perdido Groundwater Contamination site is located in the Town of Perdido, Baldwin County, Alabama. Site contamination occurred as a result of a 1965 train derailment on the Louisville and Nashville Railroad (now CSX Transportation, Inc.). Chemical (particularly benzene) from derailed tank cars spilled into drainage ditches, infiltrating the underlying aquifer. The area of ground water contamination covers approximately 15 acres and is centered downgradient about 300 yards from the derailment site. The Alabama Department of Public Health, Division of Public Water Supply (ADPWS) first documented reports of taste and odor problems in resident's water wells in 1981. Further studies showed benzene contamination in 6 of 27 wells, which led to supplying bottled water to 250 affected residents. The selected remedial action for this site includes: ground water pump and treatment using air stripping or activated carbon adsorption with the reinjection of treated water back into the aquifer, and air monitoring during operations; and ground water monitoring to measure success of the cleanup. The estimated capital cost for this remedial action is $169,000 with estimated annual O&C cost of $103,000.