SITE INFORMATION AND CORRESPONDENCE

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Mr. Eric J. Holm March 26, 1997 Page 2 2. Delta proposed fifteen sampling locations at the Site: Three are located in the area adjacent to the dip tanks; three are located east of Building No. 5, three are between Buildings No. 9 and 10; three are around Building No. 17, and three are around Building 16. DTSC's comments: The proposed soil gas sampling locations are not adequate for the purpose of delineating extent and source(s) of the contamination in soils and/or groundwater beneath the Site. Based on Delta's Phase I Environmental Assessment Report, BEM's soil and groundwater sampling results, Holz's operational and chemical usage history, and local hydrogeology, DTSC believes that additional soil and soil gas sampling are needed in the following areas: (1) Dip Tank Area. Solvents are used in the four dip tanks located in the northeast of the Site for cleaning and preparation of the metal for rubber adhesion. Drums containing solvents including TCE, PCE, 1,1,1-TCA, methyl-ethyl-ketone (MEK), methyl-isobutyl-ketone, toluene and methylene chloride are stored in the paved storage yard located to the south of the dip tanks. Elevated levels of VOCs and other contaminants have been found in groundwater beneath this area. Historically, approximately 3,000 gallons of caustic solution was released from the dip tank into the concrete containment structure in April 1988. To determine the sources of the metals, VOCs, and semi-VOCs found in groundwater beneath the Site, and the extent of the contamination in this area, additional soil gas samples at 10, 20, and/or 30 feet need to be collected in areas up gradient and beneath the dip tanks,the paved storage yard, along the sewer lines, at the floor's drains, and the parking lot. Soil samples should be collected in the above specified areas to determine if the soil is contaminated with semi-VOCs,metals, and phenolic compounds. (2) Building No. 1, "Cement Mix" and "Cement Application" Area. Building No. 1 consists of a quality control laboratory,plant management offices and the metal roll building department. Adhesive chemicals and solvents (i.e., Chemlock) are mixed in the"Cement Mix"and"Cement Application" areas for application in the spray booth.