ARCHIVED REPORTS_SITE CONCEPTUAL MODEL 2009

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ameO Effluent from ASB-2 is used to irrigate 86 acres of orchards surrounding the northern half of the Neenah Paper facility and percolation fields to the south near the Stanislaus River. Average daily discharge was approximately 1.2 MGD in 2005 (Lawrence and Associates, 2005). Between June 26 and August 16, 2007, NP discharged 135.6 acre-feet of low TDS water (about 0.87 MGD on average) purchased from SSJID as a corrective action to decrease TDS levels by flushing with low TDS water (Lawrence and Associates, 2008). The low TDS water was discharged to the east orchard, between the NP facility and Highway 99, and resulted in a localized decrease in TDS (Lawrence and Associates, 2008), as the imported water pushed the high TDS water farther from the NP facility property. Prior to 1975, Simpson Paper Company (predecessor to Fox River Paper Company and NP), discharged industrial effluent to the Stanislaus River (Lawrence and Associates, 2005), but land application has occurred since 1975. The daily rate of water disposed of by NP on its property is similar to that for the WWTF, however, actual infiltration rates are probably lower at NP because of enhanced evapo- transpiration due to the orchards. Nonetheless, the influence of the land application of industrial water on the NP property is evident from the higher water levels that are beneath the western portion of the NP property, where the apparent hydraulic mound appears to merge with the mounding conditions near the WWTF (as shown in potentiometric surface maps included as Appendix F). 4.3.3 Groundwater Pumping There are three major users of groundwater in the Study Area: 1. City of Ripon municipal supply wells — eight production wells were operated in 2007, average monthly flow rates exceeding 1,000 gpm were reported for MW-10 and MW-13. 2. Neenah Paper—three industrial supply wells were pumped throughout 2007 at combined flow rates of approximately 860 gpm. 3. Nestle groundwater extraction wells —four extraction wells were pumped at a total average annual flow rate of approximately 600 gpm. The operations of each are described below. City of Ripon Municipal Supply Wells Municipal wells MW-3, MW-5, MW-7, MW-9, MW-10, MW-11, MW-13 and MW-14 were pumped in 2007 for municipal water supply. Total water production in 2007 was approximately 5,300 acre-feet; annual average production was approximately 4.7 MGD (peak production was > 5,500 gpm in July 2007). The total annual water production of 5,300 acre-feet, allocated AMEC Geomatrix, Inc. I:\Doc_Safe\9000s\9837.005\4000 REGULATORY\SCM_01.30.09\1_text\SCM Report Final.doc 32