Manufacturing Facility

Abilene, Kansas

When chlorinated solvents were found in a city drinking water supply well close to a manufacturing facility, the State regulatory agency ordered the property owner to conduct a site investigation. To support a risk assessment and feasibility study, Roux Associates performed several investigative tasks which included installing monitoring wells, drilling soil borings, and conducting soil-gas surveys and cone penetrometer testing. GeoprobeTM sampling and aquifer tests of overburden and limestone bedrock aquifers were also performed. A plume of chlorinated solvents was identified in the overburden and bedrock aquifers.

Roux Associates was requested to conduct a preliminary risk assessment to determine potential current and future risks associated with use of the plume for domestic purposes. Data from the investigations were used to construct a groundwater flow and transport model to assist in evaluating the lateral extent of the plume over a period of years and the influence that a proposed interim remedial measure (IRM) would exercise on the plume extent. Potential risks were predicted at a point within the plume, at the proposed IRM location, at the point where the plume was expected to discharge into a river, and at a point halfway between the proposed IRM and the river. Risk estimates were based on modeled concentrations of the chlorinated solvents at each receptor point assuming no remedial action and assuming the presence of the proposed IRM.