Relationship Between Contaminated Ground Water Concentration Levels and Explosion Potentials in Sewer Systems

This paper establishes methods to estimate ground water cleanup levels based on the potential for vapors to accumulate in sewer systems from infiltrating ground water containing dissolved contaminants. The analysis assumes that no free product phase is present and thai the sewer system has a circular cross section. The methods presented can be applied to any volatile chemical contaminant which may he released into the subsurface environment. Simplifying assumptions are made to establish relationships between the target ground water cleanup levels Cgw, the hydrocarbon vapor concentration in the sewer Cv, and the depth of the waler level d, in the sewer. The paper presents sample calculations of target ground water cleanup levels for the release of fresh and weathered gasoline into the subsurface environment.