ARCHIVED REPORTS_2013 ANNUAL REPORT

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Discussion BESST performed a dynamic flow and water chemistry profile on City of Ripon well MW-3 on November 13th and thl4th, 2013. The dynamic flow profile was performed using the USGS Tracer Pulse Dynamic Flow Profile method to investigate potential leaks in blank well casing, and to determine flow contribution from the open bore hole below the pump (Figures 2 through 5). Available well information is summarized in the Introduction (Fig.1). Flow Contribution: A dynamic flow test was conducted on November 13th, 2014. MW-3 does not have screen installed, instead, blank casing ends at 127' bgs and is followed by an open borehole. Well construction information identifies the bottom of the borehole at 156' bgs, however, based on a video survey conducted one day prior to profiling, the well bottom is observed at 140' bgs. This indicates that sediments have filled in a portion of the borehole. BESST Inc. has determined that at a pumping rate of 1130 gpm,the 13 ft open hole contributes 91%of the flow (Fig. 3), while the blank casing above the pump contributes about 9%, indicating flow intrusion in this area. Due to resolution limits of the technology, we are unable to discretize the open borehole any further without compromising data accuracy. Chemistry: BESST conducted dynamic water quality sampling using the pressurized mini bailer sampling method on November 14th, 2013, collecting seven (7) water samples at depth. Lab sample results are summarized by analyte in table 1 (page 11), and calculated zonal analyte concentrations are summarized on table 2 (page 12). Figures 7 through 11 (pages 13—17) show the dynamic chemical contribution of the analyte vs.the sampling depth interval (ft.bgs). The zonal concentration is calculated by "flow weighting" the cumulative lab results using the standard mass balance algorithm. When working with samples that are measured "below laboratory detection limit", in order to still perform the mass balancing calculation, a number one-half of the detection limit was selected. This adds a degree of uncertainty as to exactly how low the measured value actually was, but the calculated value is still a useful number in that it yields a relatively low incremental concentration. Also, it should be noted that a sample was taken at 132' bgs but a mass balance calculation was not calculated due to limited flow resolution at this depth. Some overall patterns in the water quality distribution are as follows: • All five (5) analytes are below the MCL as defined by the EPA drinking water standards. • TCE and cDCE both have an asymmetrical distribution. Even though all concentrations of the respective analytes are below MCL, the concentrations of TCE and cDCE below the pump are about 15 times higher than in samples taken above the pump. • Nitrate (as N) concentration gradually increases by about 1.4 mg/L over the entire profile length with the higher concentrations near the well bottom. -Chloroform concentration is about 0.2 mg/L higher in samples taken above the pump than samples taken from below. BESSTINC. Flow and Chemistry Report well MW-3 3 CLOEWL 5UBURFACE 1,130 USG*min-1 TECHNOLMIES