This Site is the location of a pump house for an inactive municipal drinking water wellfield which had remained unused for at least 20 years.  Contaminated soil was discovered under the building slab during the demolition of an old pump house. The suspected source of contamination was from former diesel powered pump equipment. The release area was located within a Zone II for the water supply, therefore contaminant plume delineation and successful Site remediation was important. CDW performed remedial activities including the excavation and off-site disposal of approximately 400 cubic yards of impacted soil. A monitoring well was subsequently installed adjacent and downgradient of the excavation area. Two rounds of groundwater analysis indicated that concentrations of petroleum compounds decreased to below applicable standards and a Class A-2 RAO was prepared to achieve regulatory closure. A new pump house was constructed in it’s place for possible use of the wellfield as a backup municipal water supply in the future.