Wednesday, March 11, 2015

Progress in Remediation of Groundwater at Petroleum Sites in California



Progress in Remediation of Groundwater at Petroleum Sites in California
Type
Journal Article
Author
Thomas E. McHugh
Author
Poonam R. Kulkarni
URL
Volume
52
Issue
6
Pages
898-907
Publication
Groundwater
Date
2014
Abstract
Quantifying the overall progress in remediation of contaminated groundwater is challenging. Researchers used the GeoTracker database to evaluate the progress in groundwater remediation from 2001 to 2011 at over 12,000 sites in California with contaminated groundwater. They present an analysis of analytical results from over 2.1 million groundwater samples representing at least $100 million in laboratory analytical costs. Their evaluation of monitoring data reveals a large decrease in groundwater concentrations of gasoline constituents. For benzene, half of the sites showed a decrease in concentration of 85% or more. For methyl tert-butyl ether (MTBE), the decrease was 96% and for TBE, 87%. At remediation sites in California, the median source attenuation rate was 0.18/year for benzene and 0.36/year for MTBE, corresponding to half-lives of 3.9 and 1.9 years, respectively.
Attenuation rates were positive for benzene at 76% of sites and for MTBE at 85% of sites. An evaluation of sites with active remediation technologies suggests differences in technology effectiveness. The median attenuation rates for benzene and MTBE are higher at sites with soil vapor extraction or air sparging compared with sites without these technologies. In contrast, there was little difference in attenuation rates at sites with or without soil excavation, dual phase extraction, or in situ enhanced biodegradation. The evaluation of remediation technologies, however, did not evaluate whether specific systems were well designed or implemented and did not control for potential differences in other site factors, such as soil type.

No comments:

Post a Comment