UNITED STATES ENVIRONMENTAL PROTECTION AGENCY • REGION IX • SAN FRANCISCO, CA • NOVEMBER 2000 U. S. EPA Announces Public Comment Period on the Proposed Plan for Aerojet Superfund Site — Western Groundwater Operable Unit The United States Environmental Protection Agency (EPA) is requesting comment on the Proposed Plan for the Western Groundwater Operable Unit of the Aerojet Superfund site in Rancho Cordova. This document describes alternatives for cleanup of groundwater contamination at the western end of the Aerojet-General Corp. property. What is the problem? Groundwater contamination is expanding outward from the westward side of the Aerojet Superfund site into Rancho Cordova (Figure 1). The contamination contains perchlorate and N-Nitrosodimethylamine (NDMA) from rocket fuel components and/or their combustion products as well as volatile organic compounds (VOCs) primarily from cleaning solvents. Groundwater contamination has already forced the shut-down of seven public water supply wells in the area. The spread of contaminated groundwater threatens 13 more wells, despite the continued operation of a groundwater treatment system on the Aerojet property. What does EPA propose to do about it? Out of several cleanup alternatives EPA has studied, EPA prefers an alternative that would install several new ground- water extraction wells off the Aerojet property near the head of each plume of contamination. Contaminated groundwater would be pumped out and treated to remove perchlorate, NDMA, and VOCs. Treated water would be discharged to a surface water- course leading to the American River, and land-use controls would prevent future drilling of wells into the contaminated aquifer. What else has EPA considered? EPA has considered several other alternatives, including: • taking no action, • providing replacement water supplies as wells become contaminated, • using existing drinking-water wells to extract and treat contaminated groundwater, • several different configurations of extraction wells (one of which is EPA's preferred alternative), and • different configurations of reinjection wells, both on- and off-property, along with extraction wells. EPA is also considering different options for discharging of treated water. Where can I find more information? You can find more detailed information on the Western Groundwater Operable Unit of the Aerojet site in the Reme- dial Investigation and Feasibility Study report, and other (Cont'd on back) 2500 5000 Maximum Extent of COPCs — — — Western Groundwater Study Area Boundary Aerojet Site Boundary Figure 1: The vicinity of Aerojet Superfund Site (western groundwater contamination shaded) ------- technical documents. These documents are part of the Administrative Record for the site. They are available for review by members of the public at the information reposito- ries for this site: Superfund Records Center 95 Hawthorne Street, Suite 403S San Francisco, CA 94105-3901 415-536-2000 California State University-Sacramento Library 2000 State University Drive East Sacramento, CA 95899-6039 916-278-5672 Community Meeting Thursday, December 7, 2000 7:00 PM to 9:00 PM Mills Middle School 10243 Coloma Road Rancho Cordova, CA 95670 If you want to ask questions, receive a copy of the Proposed Plan, or add your name to the mailing list for the Aerojet Superfund site, please call the EPA Office of Community Involvement toll-free at 800-231-3075 and leave a message for Don Hodge, Community Involvement Coordinator, or send a message via email to hodge.don@epa.gov What can I do? EPA encourages members of the public to review and comment on all alternatives described in the Proposed Plan and other site-related documents. If you are on EPA's mailing list for the Aerojet site, you will be receiving a copy of the Proposed Plan in the mail. Other documents are available in the information repositories for the site. You can submit comments on the Proposed Plan during the Public Comment Period from December 1, 2000 to January 30, 2001. Public Comment Contact Charles Berrey, Remedial Project Manager U.S. EPA Region 9 75 Hawthorne Street (SFD-7-2) San Francisco, CA 94105-3901 Telephone: 415-744-2223 or 800-231-3075 Fax: 415-744-1796 E-mail: berrey.charles@epa.gov Note: Comments must be postmarked or received via e-mail and fax by January 30, 2001. You may also attend the community meeting that EPA will conduct on this Proposed Plan. FIRST CLASS MAIL POSTAGE & FEES PAID U.S. EPA Permit No. G-35 United States Environmental Protection Agency Region 9 75 Hawthorne Street (SFD-3) San Francisco, CA 94105 Attn: Don Hodge Official Business Penalty for Private Use, $300 Address Service Requested ------- |