Assessing the Effectiveness of Contaminated Sediment Remediation in the Housatonic River, Massachusetts

摘要

The Housatonic River is contaminated with polychlorinated biphenyls(PCBs) that originated from the General Electric Company (GE) facility in Pittsfield,MA. The purpose of this study was to evaluate the recovery of benthic macroinvertebrateand fish populations in the 1 1/2-Mile Reach of the East Branch of the Housatonic, an areathat was remediated from 2002 to 2006. River sediment, benthic invertebrates, and fishwere sampled from three locations in June 2007. The results were compared to samplescollected at the same locations in 2000, prior to the start of remediation. Sediment PCBconcentrations following remediation were reduced from the pre-remediation concentrationsby approximately 99% (from a range of 6.6 milligrams per kilogram [mg/kg] dryweight [dw] - 93.2 mg/kg to 0.07 - 0.24 mg/kg dw). The decrease in sediment PCB contaminationwas reflected in a 99.5% decrease in benthic invertebrate tissue PCB concentrations(from 336.5 mg/kg wet weight [ww] to 1.62 mg/kg ww). Post-remediationbenthic invertebrate populations showed an increase in diversity, abundance, and biomassat all locations sampled, and pollution-intolerant species (Ephemeroptera, Plecotera,Trichoptera [EPT] taxa) were markedly increased. Results of the fish sampling indicatedthe presence of a diverse and abundant post-remediation fish community, with noticeablygreater fish presence in the vicinity of stone structures installed as part of habitat restorationin the river channel. In combination, these results indicate that the remediationconducted in the 1?-Mile Reach of the Housatonic River has been successful in substantiallyreducing PCB contamination in river sediment and that reduction is reflected in theresident biota, and that the biota have successfully re-colonized the 11/2-Mile Reach.