PB95-963125 EPA/ESD/R09-94/130 March 1995 EPA Superfund Explanation of Significant Difference for the Record of Decision: South Bay Asbestos, Alviso, CA 10/18/1993 ------- . . , ~ South Bay Asbestos Superfund Site Ring Levee Operable unit Explanation of Significant Differences to the Record of Decision United States Environmental Protection Agency Region IX -San Francisco, California October 1993 ------- -'.' . . EXPLANATION OF SIGNIFICANT DIFFERENCES SITE NAME AND LOCATION South Bay Asbestos Superfund site Ring Levee Operable Unit San Jose, California STATEMENT OF BASIS AND PURPOSE This decision document presents this Explanation. of Significant Differences ("ESD") to the remedial action selected by the United States Environmental Protection Agency ("EPA") for the Ring Levee Operable unit at the South Bay Asbestos superfund Site in San Jose, California. EPA selected the remedial action for the Ring Levee Operable Unit in a R,ecord of Decision Amendment ("ROD") dated June 1991 (# ROD/R09/91/061) (amending # R09-88/026). The overall remedy for the remainder of the site was selected by EPA in a separa~e Record of Decision dated September 29, 1989 (# ROD/R09/89/044) and is not impacted by this ESD. This. ESD was developed in accordance with the applicable provisions of the Comprehensive Environmental Response, Liability, Compensation, and Liability Act (42 U.S.C. Section 9601 et sea., as amended) (CERCLA) and the National ,contingency Plan (40 C.F.R. section 300 et sea.). This ESD is based on the administrative record for this Operable unit and is issued under the authority established in Section 117(c) of CERCLA, 42 U.S.C. 59617(c). This ESD and supporting documents will become part of the administrative record for the South Bay Asbestos Superfund site. The Administrati ve Record for the Site is available for public inspection and review at the Alviso Branch of the San Jose Public Library' located at 1060 Taylor Street, Alviso, California and at the Family Health Foundation located at 1621 Gold Street, Alviso, California.' . EPA is the lead agency for the South Bay Asbestos Superfund site. The modification of the remedy for the Ring Levee Operable Uni t as set out in this ESD has been discussed wi th state and federal support agencies including: California EPA-Department of Toxic Substance Control, the California Department of Health Services, the California Department of Fish and Game, Cal-Trans, the Santa Clara valley Water District, the City of San Jose, the United States Army Corps of Engineers, the united States Agency for' Toxic Substances and Disease Registry and the United States Fish and wildlife Service. . DESCRIPTION OF THE SELECTED REMEDY IN THE ROD The South Bay Asbestos Superfund Site was proposed for inclusion on the Superfund National Priorities List ("NPL") in June of 1984 and was listed on the NPL in October 1984. EPA has been ------- , ~ . -2- the lead agency for Superfund activities at the South Bay Asbestos Superfund site since 1986 when the lead-agency role was transferred from the state to EPA. The Alviso Ring Levee was constructed in March 1983 by the City of San Jose as an emergency measure in response to extensive flooding in the community of Alviso. Later investigation by state agencies revealed that the material used to construct the Ring Levee was serpentine soil rock containing up to 40% asbestos. Since 1986 the Ring Levee has been regularly sprayed, first by EPA and subsequently by the City of San Jose, with a dust suppressant sealant to minimize any risk of an airborne release of asbestos from the Ring Levee. The Ring Levee has also been regularly inspected by EPA and the City of San Jose. In 1992, the City of San Jose erected fences, signs and barriers along a significant. portion of the Ring Levee to eliminate the use of the Levee by local residents. The Ring Levee Operable Unit ROD Amendment selected a remedy with the following components: 1) removal of .the .entire asbestos contaminated ring levee following completion of the Coyote Creek Flood Control Project, 2) off-site disposal of the levee material in compliance with state and federal requirements, 3) restoration of the previously existing wetlands underlying the levee as well as mitigation for lost wetlands values, 4) implementation of dust control measures prior to and during levee removal. The remedy was estimated to cost approximately $2.1 million. SUMMARY OF SIGNIFICANT DIFFERENCES As a result of this ESD, the remedy for the Ring Levee Oper~ble unit is modified to allow the removal of the ring levee in the fall of 1993 approximately two years prior to the anticipated completion of the coyote Creek Flood Control Project. Because of concerns, voiced by the Santa Clara Water District and the City of San Jose, that a ring levee around the Community of Alviso is necessary to provide some degree of flood control, this ESD also modifies the remedy for the Ring Levee Operable Unit to require that an interim replacement levee be constructed using. clean material. Finally, this ESD modifies the remedy for the Ring Levee Operable unit to require that the replacement levee be removed within one year following the completion of the Coyote Creek Flood Control Project. . This ESD does not alter the schedule for restoration of the wetlands which previously existed beneath the ring levee or the wetlands mitigation effort required by the existing Consent Decree between the United States, the City of San Jose and A.J. Raisch Paving Company. As established in the ROD, the wetlands mitigation and restoration activities will occur following the permanent removal of the ring levee which in turn will follow upon the completion of the Coyote Creek Flood Control Project. ------- . -\ . ...." -3- DECLARATION After consideration of the changes made to the selected remedy by this ESD, the remedy for the Ring Levee Operable Unit of the South Bay Asbestos Superfund si te meets the remedy selection standards of CERCLA section 121, 42 U.S.C. 59621, and the National Contingency Plan, 40 C.F.R. P~rt 300. The selected remedy, as modif ied by this ESD, is protective of human heal th and the environment. The selected remedy, as modified by this ESD, attains the Federal and State requirements that are legally applicable or relevant and appropriate under the circumstances of the release, and is cost effective. This remedy, as modified by' this ESD, utilizes permanent solutions and alternative treatment technologies to the maximum extent practicable; however, because treatment of the principal threats of the site was not found to be practicable, this remedy, as modif ied by this ESD, does not satisfy the statutory preference for treatment as a principal element. & . C . W \A.I-. Jo. C. Wise Deputy Regional Administrator 1t:)./S.li' Date ,. . ------- |