SITE INFORMATION AND CORRESPONDENCE

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Mr. Mike Desso - 2 - 19 November 2007 Nestle USA Inc. layer is between approximately 30 to 45 feet bgs, has TCE concentrations up to 2,500 Pg/L, and is less extensive. The primary objective of the IRAP is to stop continued migration of VOCs in shallow groundwater away from the Former Facility. An additional objective is to reduce the concentrations of VOCs dissolved in groundwater. Nestle presented an evaluation of four methods to achieve the objectives: 1. Groundwater extraction and treatment exclusively from upper zone extraction wells. (Note: The existing treatment system that ECM operates at the Former Facility would be modified to improve the capture of dissolved-phase VOCs in groundwater within the sand immediately beneath the clay layers.), 2. In situ reductive dechlorination by zero-valent iron, 3. Enhanced in situ bioremediation, and 4. In situ chemical oxidation by activated persulfate injection and ozone sparging. In the IRAP, Nestle proposed to proceed with the first method listed above: Groundwater extraction and treatment exclusively from upper zone extraction wells. Treated water would continue to be conveyed to the City of Ripon wastewater treatment plant. In the 19 September 2007 review letter, Regional Water Board staff concurred with their proposal, provided Nestle addressed the comments listed below: 1. The installation of shallow extraction wells screened within the sandy material with elevated concentrations of VOCs should be implemented in such a way as to maximize gradient control. Nestle should utilize the groundwater model developed for the site. 2. The monitoring well network should be configured to monitor horizontal and vertical groundwater flow gradients. A monitoring well should be installed across the groundwater table at well nest M-6. This should enhance the vertical flow gradient monitoring capabilities. 3. The additional objective to reduce concentrations of VOCs dissolved in groundwater could be enhanced with implementation of an in situ remediation technology. Nestle should continue their evaluations of the other three technologies evaluated in the IRAP as well as other possible technologies not yet evaluated. Work Plan The Work Plan proposes the installation and development of two groundwater extraction wells and four groundwater monitoring wells screened within the sand layer identified in the IRAP as the layer containing the largest mass of dissolved TCE. The screens will be placed between 50 and 60 feet bgs. However, Nestle is prepared to modify the screen intervals in the field if the targeted sand layer occurs at a different interval in any of the well soil borings. Also, for proper sizing of extraction well screens and filter packs, Nestle will perform sieve analyses of