||Explanation of significant difference for the superfund record of decision : Commencement Bay, South Tacoma Channel, Tacoma, WA.
||Environmental Protection Agency, Washington, DC. Office of Emergency and Remedial Response.
|| [U.S. Environmental Protection Agency, Office of Emergency and Remedial Response],
Hazardous waste sites--Washington.
Hazardous materials ;
Waste management ;
Commencement Bay ;
Ethyl benzene ;
Ground water ;
Site characterization ;
Remedial action ;
ESD(Explanation of Significant Difference) ;
Explanation of Significant Difference ;
Record of Decision ;
South Tacoma Field ;
Pierce County(Washington) ;
Volatile organic compounds ;
Natural attenuation ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
||12 pages : illustrations, maps ; 28 cm
This document presents an Explanation of Significant Differences (ESD) from the Record of Decision (ROD) for South Tacoma Field, which was signed by the United States Environmental Protection Agency in September 1994. In addition to source removal during underground storage tank (UST) excavations, groundwater contaminant levels have greatly decreased since the Remedial Investigation in the early 90's. The responsible parties have investigated the area and found that the contamination is isolated and the levels have dropped. Because of this, the responsible parties asked EPA to re-evaluate the need to install the air sparging and vapor extraction systems. EPA has determined that these systems are no longer necessary to address the groundwater contamination at Pioneer. This ESD changes the selected remedy at Pioneer from air sparging and vapor extraction to monitored natural attenuation and institutional controls.
Cover title. "9/29/1999." "PB99-963114." "EPA/541/R-99/065." "1999." Microfiche.