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LOGE 1844: Farris NLS Addendum Page 4 March 5, 2019 Table 1. Estimate of Deep Percolation of Rainfall for Ripon, CA. Month Average Rain- Average Potential Annual Potential Fall (inches) Evapotranspiration Deep Percolation of (inches) Rain (inches) January 2.44 1.24 1.20 February 2.07 1.96 0.11 March 1.93 3.41 None April 1.03 5.10 None May 0.46 6.82 None June 0.13 7.80 None July 0.02 8.06 None August 0.04 7.13 None September 0.17 5.40 None October 0.63 3.72 None November 1.24 1.80 None December 2.05 0.93 1.12 Totals 12.21 53.37 2.43 Notes: CIMIS evapotranspiration information at wwwcimis.water.ca.gov/cimis/for ETo Zone 12. Rainfall from Modesto City County Airport station (045738). Closest active station to Site was selected. • Reduced Rainfall: For this method, rainfall levels from the closest rain station are multiplied by a percentage based on a reasonable assumption from the literature. Because the Hantzsche and Finnemore model utilized a value of approximately 75 percent rainfall as the rate of recharge from percolating waters in the Chico area, that value is applied to local rainfall in the project area. The San Joaquin County Environmental Health Department recommended this approach in 2017, with the understanding that it would better characterize recharge within the County (personal communication with Rodney Estrada, Lead REHS, January 6, 2017). As discussed above, Modesto City-County Airport station (045738), the closest active station to the Site, reports the average total annual precipitation from March 1906 through June of 2016 to be 12.21 inches (Table 1). Assuming 75 percent of this precipitation percolates to the aquifer (as Hantzsche and Finnemore did in Chico), the rate of recharge from percolating waters is calculated to be an average of 9.2 inches per year. • Regional Recharge from Percolating Waters: In 2018, the Eastern San Joaquin Groundwater Authority (ESJGA) commissioned a comprehensive