ENHANCED NATURAL ATTENUATION OF CHOLRINATED ALIPHATIC HYDROCARBONS (CAHs) AT CUDAHY BUSINESS PARK – PARCEL 3
Lisa M. Smith
Due to the high industrial use of chlorinated solvents, CAH contaminated groundwater is now a common problem. Natrual attenuation consists of naturally-occurring processes in the soil and groundwater that reduce the mass, toxicity, mobility, volume, or concentrations of contaminants. Natural attenuation of petroleum contaminated groundwater utilizing microbial degradation is a commonly accepted remediation alternative. However, the use of natural attenuation for CAHs is a lesser accepted and a newer alternative that requires specific groundwater conditions.
Natural attenuation has many advantages. The cost is usually much lower than other remediation techniques such as pump and treat. Natural attenuation is also a popular remediation option since it is generally noninvasive and does not require additional surface structures. Also, since the toxic solvents are degraded to nontoxic constituents such as methane, ethane, and ethane in the subsurface, the toxic compounds are not brought to the surface. This avoids possible release to the atmosphere or exposure to human receptors.
The CAH contaminated groundwater at the Cudahy Business Park – Parcel 3 Site is being remediated using natural attenuation. To increase the potential for natural attenuation success, the source of contamination has been removed and whey has been placed at the bottom of the excavation site to increase the organic carbon source.
This research will show that natural attenuation of CAHs is a successful remediation alternative and that removing the contaminant source and increasing the organic carbon and nutrients in the subsurface, increases the success of natural attenuation and shortens the time required for CAH degradation.