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GES GENESIS ENGINEERING&REDEVELOPMENT 1. Nitrate concentrations in the extraction wells decrease to 200 mg/L nitrate as NO3, or 2. Nitrate concentrations reach an asymptotic value in the extraction wells. 2.0 SCOPE OF WORK The objective of the Work Plan is to mitigate nitrate impacts by extracting groundwater and discharging it to the City of Ripon NPWS. A secondary benefit of pumping is that the flow of groundwater induced by pumping may further distribute any remaining amendment form the Treatability Study, which may result in a reduction in nitrate concentrations by denitrification. Specifics regarding these stages as well as design configuration are presented in the following sections. 2.1 Groundwater Extraction Overview The two main factors that control the design of the extraction system are: 1. The rate at which individual extraction wells can be pumped; and 2. The NPWS limits on the concentrations of nitrate (1,000 mg/L) and total dissolved solids ("TDS") (2,500 mg/L) that can be discharged to the system. Quantitative evaluations of aquifer transmissivity and well capacity have not been performed. However,based on the geologic materials in shallow groundwater(i.e. primarily sand and silty sand),the length of prosed screened intervals in the extraction wells (i.e. up to 25 feet), and drawdown measurements made during well purging prior to sampling, it is anticipated that individual wells can be sustainably pumped at approximately 20 gallons per minute ("gpm"). Sustainable pumping rates will be determined during system start up, and may vary through time. Nitrate and TDS concentrations in groundwater in the center of the Site exceed the NPWS limits, and therefore water from the extraction well(s) in this area must be blended with water pumped from other wells to dilute nitrate and TDS concentrations below the NPWS limits. To accomplish this blending, additional extraction wells will be installed outside the area of highest groundwater impact. Based on the distribution of nitrate and TDS throughout the Site, groundwater will be initially be extracted from four wells (Figure 6). Preliminary calculations indicate that NPWS nitrate and TDS limits can be met if one well is pumped in the center of the Site where nitrate concentrations are highest (existing well AT- 1 S) and three wells are pumped in areas of lower nitrate and TDS on the western part of the Site(proposed wells EX-1, EX-2, and EX-3). The pumping rates and which wells are pumped are expected to change over time as nitrate and TDS concentrations change in response to pumping. When pumping rates/locations are adjusted, the goal will always be to a F.Land Inc. 4 of 11 Groundwater Extraction Work Plan October 2014