MIDDLE WATERWAY SEDIMENT REMEDIATION:A CASE STUDY

摘要

The Middle Waterway,located in Tacoma,Washington USA,is approximately 3,500 feet long and is typified by areas utilized for both waterway commerce and critical fish habitat.The Middle Waterway Action Committee (MWAC)has completed pre-remedial design,remedial options analysis,and remedial design for cleanup of the Middle Waterway.Working under the US Environmental Protection Agency(EPA)Superfund program for the Commencement Bay Nearshore/Tideflat site,the remediation plan includes dredging,thin-layer capping,and natural recovery.Approximately 85,000 cubic yards of dredged material from the navigation channel will be disposed of in a nearshore confined disposal facility(CDF)to support economic development.Due to listing of several fish species under the Endangered Species Act(ESA)as threatened or endangered,the remediation plan has been designed to support the remediation of contaminated sediments,the protection and creation of critical habitat to support salmon recovery,and waterway commerce.The successful integration of these potentially divergent objectives has been key to support by EPA,industry,resource agencies,and public interest groups.Final design plans are expected to be approved in late 2001 with the construction beginning in 2003.