Hilmar, CA. Subject: 1Q2008 2Q2011 Hilmar. Figure 1.

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2 August 25, 211 Burt Fleischer, R.E.A., R.E.P. Director, Environmental Affairs 91 N. Lander Avenuee Hilmar, CA Subject: Former Primary Land Use and Upper Aquifer Groundwater Quality Trend Update: 1Q28 2Q211 Hilmar Cheese Company, Dear Mr. Fleischer: Jacobson James & Associates, Inc. (JJ&A) has prepared this transmittal to provide a review of the status of the former Primary Lands and Upper Aquifer groundwater quality trends for the Hilmar Cheese Company (HCC) facility located in. The HCC facility is located at 91 Lander Avenue and the former Primary Lands were located adjacent to and surrounding the facility as shown on Figure 1. This transmittal is provided pursuant to the Cleanup and Abatement Order (CAO) No. R , issued by the Central Valley Regional Water Quality Control Board (CVRWQCB) on December 2, 24. The objectives of this transmittal are to: (1) review the landd use for the former Primary Lands; and, (2) provide trend data evaluating Upper Aquifer groundwater quality over time. The transmittal provides the trend analysis for the January 28 to June time period. This period of time was selected to: (a) provide some historical perspective representative of when discharges to the Primary Lands (28 29) occurrred, (b) include 21 when the volume of discharges to Primary Lands was significantly reduced 2 with termination in December 21, and (c) include data for the period of time post Primary 1 The period of time shown for wells that were installed later than January 28 reflects their first sample date. 2 Total discharge for 21 was 15.4 million gallons as compared to 25.8 and million gallons in 29 and 28, respectively. HCC_Land Use and Upper Aquifer Trend Transmittal_211Aug25_FINAL

3 Technical Memorandum: Land Use and Groundwater Quality Trend Update, Hilmar California August 25, 211 Page 2 of 6 Land discharge when standard irrigation practices were occurring through the second quarter of 211. The data summarized herein has previously been submitted to the CVRWQCB under separate cover. The Technical Memorandum is organized as follows: Background Information Status of Former Primary Lands Upper Aquifer Groundwater Quality Trend Data Transmittal Closure BACKGROUND INFORMATION Treated facility wastewater was historically discharged to areas identified as the Primary Lands. The discharge to Primary Lands began in 1989 and were regulatedd by Waste Discharge Requirements (WDRs) issued by the Central Valley Regional Water Quality Control Board (CVRWQCB). The most recent WDR was issued as Order No. R5 21 8, as modified by thee Time Schedule Order (TSO) No. R5 21 9, which required that all discharge to the Primary Lands cease as of February 15, 211. Discharge to the Primary Lands was significantly reduced in 21 and the last discharge was in December 21. Fully treated facility wastewater has been, and continues to be, discharged to areas identified as Reuse Areas (historically referred to as Secondary Lands) for irrigation. The current location and configuration of Reuse Areas in the vicinity of the former Primary Lands iss shown on Figure 2. As shown on Figure 2, portions of the former Primary Lands are now identified as Reuse Areas S 63, S 64 and S 65; the application of waters to these locations is regulated by WDRss Order No. R Monitoring wells have been installed at the facility, former Primary Lands and surrounding areas to meet the requirements of the historic and current WDRs and the CAO. The monitoring wells subject to the WDRs in the vicinity of the former Primary Lands provide data relevant to the CAO activities. The monitoring wells subject to both the WDR and CAO addressed by this transmittal are shown on Figure 2. The monitoring wells provide dataa on water levels and groundwater quality in the Upper Aquifer and Lower Aquifer, which are separated by the Corcoran Clay. The water level and groundwater quality data are currently collected on a quarterly basis. Quarterly reports are provided to the CVRWQCB to transmit the WDR and CAO dataa under separate cover. STATUS OF FORMER PRIMARY LANDS The former Primary Lands are used for agricultural purposes. Figure 3 provides a graphical land use timeline for the former Primary Lands beginning with December 21, when the last Primary Land

4 Technical Memorandum: Land Use and Groundwater Quality Trend Update, Hilmar California August 25, 211 Page 3 of 6 discharge occurred. As shown on Figure 3, portions of the former Primary Lands became Reuse Areas S 63 and S 64 in March 211 and Reuse Area S 65 in April 211. All Reusee Areas can receive HCC Reuse water, TID water and/or Dairy Wastewater. Quarterly WDR reports are submitted by HCC to the CVRWQCB which identify the source, volume and quality of water applied to the Reuse Areas. The information from the quarterly WDR reports is summarized in Figure 3. As indicated on Figure 3, Reuse Areas S 63, S 64 and S 65 have received only Reuse or TID water for the time period addressed by this transmittal. Water quality data for the Reuse and TID water for January through June 211 is included in Table 1. A review of the information on Figure 3 indicates the following for the period of December 21 through June 211: Threee parcels of former Primary Land have been converted to Reuse Areas S 63, 64 and 65. Reusee Areas S 63, S 64 and S 65 received water in April and Reusee Areas S 64 and S 65 received water in May. Reusee Areas S 63 and S 64 received only TID water and S 65 received both TID and HCC Reuse water. A total of approximately 36 million gallons of water wass applied to Reuse Areas S 63 through S 65; comprised of approximately 33 million gallons of TID water and 3 million gallons of HCC Reuse water. Concentrations of total dissolved solids (TDS) for the HCCC Reuse and TID water were in the range of mg/l and mg/l, respectively. Concentration of chloride in the HCC Reuse water was 666 mg/l in April and 62 mg/ /L in May; chloride in TID water is not measured. GROUNDWATER QUALITY TREND DATA Groundwater quality data graphs were prepared for the monitoring wellss that provide data pertinent to the CAO work. The graphs, provided as Attachment 1, provide constituent concentrations trends and groundwater levels for each well. The graphs provided as Attachment 2 provide well trends for the each selected constituent. The graphs identify whichh zone the data is presented for (i.e., the Upper Aquifer Shallow Zone (upper 15 2 feet) or the Upper Aquifer Supply Zone (below the Shallow Zone and above the Corcoran Clay)). The graphs prepared for the individual constituents providedd in Attachment 2

5 Technical Memorandum: Land Use and Groundwater Quality Trend Update, Hilmar California August 25, 211 Page 4 of 6 include the proposed ambient screening thresholds 3 for the Upper Aquifer Shallow Zone and the Upper Aquifer Supply Zone. Two graphs are providedd for the Upper Aquifer Shallow Zone in Attachment 2: graph 1 of 2 provides the data for wells that have generallyy had constituent concentrations above the ambient screening threshold and graph 2 of 2 provides the data for wells that have generally had concentrations below the ambient screening threshold for the specific constituent. The following sections present the data observations based on review of the graphs for the Upper Aquifer Shallow Zone and the Upper Aquifer Supply Zone. Upper Aquifer Shallow Zone A review of the monitoring well (Attachment 1) and constituent (Attachment 2) trend graphs indicates stable to declining constituent concentrations within the Upper Aquifer Shallow Zone since the first quarter of 21 except as identifiedd below. MW 5 (located in the south central portion of the formerr Primary Lands, west of the facility) o Sulfate has exhibited an increasing trend. MW 13 (located in the northeast corner of the former Primary Lands) o Nitrate has exhibited an increasing trend, although the last two quarters showed decreases. At MW 13 it is noted that although sodium, chloride and bicarbonate showed increases in 211 their overall trend is decreasing as is the trend for TDS, a more general measurement of overall water quality. MW 14 (located off site to the south and down gradient of a dairy) o Calcium has exhibited an increasing trend. The trends since the first quarter of 21 weree evaluated due to the significant reduction of Primary Land discharge in 21 with cessation in December 21. It should be noted that fluctuations in constituent concentrations are expected to occur within the Upper Aquifer Shallow Zone in response to: (1) water level and groundwater migration changes due to 3 Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJ&A, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

6 Technical Memorandum: Land Use and Groundwater Quality Trend Update, Hilmar California August 25, 211 Page 5 of 6 seasonal conditions, pumping and irrigation activities; (2) agricultural activities such as the application of manure and dairy wastewater and, (3) the aquifer s processes of establishing equilibrium conditions under the different land use conditions which no longer include Primary Land discharges. The overall trend at each well is the appropriate indicator with regards to monitoring and predicting the Upper Aquifer water quality conditions. And, as previously stated, the overall environment indicates stable to decreasing trends since the first quarter of 21. A review of the trend graphs prepared for the constituents provided in Attachment 2 indicates that: Constituents historically below the proposed ambientt screening thresholds remain below the thresholds since the first quarter of 21. Constituents historically above proposed ambient screening thresholds have generally exhibited stable to decreasing trends since the first quarter of 21 with the following exceptions: o o o Calcium at MW 14 has exhibited an increasing trend; this well is off site to the south and down gradient of a dairy. Nitrate showed an increase at MW 13 in 21 but has been decreasing in 211. Sulfate is exhibiting an increasing trend at MW 5, but iss within the historic range of detections. Upper Aquifer Supply Zone The Upper Aquifer Supply Zone monitoring wells include MW 18, 19, 22, 24, 25 and 29. The trends for these monitoring wells appear stable with recent decreases noted for MW 24. TRANSMITTAL CLOSURE Water level and groundwater quality data will continue to bee collected through the first quarter of 212 at which time the frequency and details of the monitoring and sampling program willl be reviewed with the CVRWQCB. In the interim, quarterly transmittals will be provided to the CVRWQCB with updated land use and trend graphs to allow for monitoring and confirmation of water quality trends following the 21 cessation of Primary Land discharges.

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8 TABLE

9 TABLE 1 WATER QUALITY DATA FOR HCC REUSE WATER, TID WATER AND DAIRY WASTEWATER 1 TDS (mg/l) Nitrate, as Nitrogen (mg/l) TKN (mg/l) BOD (mg/l) Reuse TID Reuse TID Reuse TID Reuse TID Jan ND (.75) Feb Mar Apr May Jun Notes: 1 TDS, Nitrate, TKN and BOD are the only parameters that are analyzed for in both water sources. Additional parameters are analyzed for in the Reuse water. Reuse data is a monthly average. TID water quality based on discrete samples for Reuse areas S63, S64 and S65. BOD = biological oxygen demand mg/l = milligrams per liter ND = non detect TDS = total dissolved solids TID = Turlock Irrigation District TKN = total kjeldahl nitrogen 1 of 1

10 FIGURES

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12 7 S-31 S-23 S-24 MW-24 &< SCALE IN FEET S-3 S-29 S-13 MW-13 OBS-1 B &< MW-16 &< MW-1 &< OSLO ROAD MW-15 &< REVERSE OSMOSIS PONDS MW-21 &< S-43 S-8 S-65 LANDER AVENUE S-44 S-25 MW-9 &< S-63 OSLO STREET MW-6 MW-22 &< &< MW-23 MW-1 &< STORM WATER RETENTION POND MW-7 &< &< AW-4 &<&< AW-3 MW-18 MW-11 LATERAL NO. 6 S-7 MW-12MW-19 &< AUGUST AVENUE MW-8 &< S-64 MW-5 &< MW-2 &< MW-4 &< MW-3 &< AW-2 &< AW-1 &< LEGEND &< B UPPER AQUIFER MONITORING WELL LOWER AQUIFER MONITORING WELL DESTROYED WELL S-58 MW-4 S-6 COLUMBUS AVENUE S-26 MW-17 MW-38 S-4 &< MW-28 S-41 &< MW-29 MW-27 MW-14 &< MW-26 &< MW-25 MW-2 &< C:\GIS\Hilmar\Basemap\Figure 2 Site Plan Reuse.mxd S-2 NOTE: HCC FACILITY REUSE AREA RECEIVING TID FRESHWATER ONLY REUSE AREA RECEIVING HCC REUSE WATER AND TID FRESHWATER EXTENT OF HCC FACILITY AND FORMER PRIMARY LANDS CURRENT REUSE AREA TURLOCK IRRIGATION DISTRICT LATERAL CANAL NOT ALL REUSE AREAS ARE SHOWN ON THIS FIGURE; THERE ARE ADDITIONAL REUSE AREAS TO THE WEST AND SOUTHWEST. LOCATION HILMAR CHEESE COMPANY HILMAR, CALIFORNIA DATE DRAWN BY APPR. BY 8/24/11 DPG SM FIGURE 2 SITE PLAN

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14 ATTACHMENT 1 MONITORING WELL ANALYTICAL AND GROUNDWATER ELEVATION VERSUS TIME GRAPHS: JANUARY 28 JUNE 211

15 4 MW 1 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

16 4 MW 2 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

17 4 MW 3 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

18 4 MW 4 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

19 4 MW 5 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

20 4 MW 6 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

21 4 MW 7 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

22 4 MW 8 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

23 4 MW 9 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

24 4 MW 1 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

25 4 MW 11 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

26 4 MW 12 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

27 4 MW 13 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

28 4 MW 14 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

29 4 MW 15 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

30 4 MW 16 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

31 4 MW 17 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

32 4 MW 18 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Supply Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

33 4 MW 19 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Supply Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

34 4 MW 2 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

35 4 MW 21 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Shallow Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

36 4 MW 22 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Supply Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

37 4 MW 24 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Supply Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

38 4 MW 25 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Supply Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

39 4 MW 29 ANALYTICAL AND GROUNDWATER ELEVATION DATA Upper Aquifer Supply Zone /1/8 5/1/8 9/1/8 1/1/9 5/1/9 9/1/9 1/1/1 5/1/1 9/1/1 1/1/11 5/1/11 (feet above mean sea level) Primary Land Use Stopped December 21 Application of Reuse Water initiated April Total Dissolved Solids (TDS) & Bicarbonate Chloride, Nitrate/Nitrite as Nitrogen, Sulfate, Calcium, Magnesium, Manganese, Potassium, Sodium Total Dissolved Solids Dissolved Calcium Bicarbonate Chloride Nitrate/Nitrite as Nitrogen Sulfate Dissolved Magnesium Dissolved Manganese Dissolved Potassium Dissolved Sodium Non detect results plotted as half of the reporting limit.

40 ATTACHMENT 2 CONSTITUENT SPECIFIC CONCENTRATION VERSUS TIME GRAPHS: JANUARY 28 JUNE 211

41 TOTAL DISSOLVED SOLIDS UPPER AQUIFER SHALLOW ZONE 1 of Total Dissolved Solids (TDS) Ambient Screening Threshold (912) 5 MW 1 MW 3 MW 5 MW 6 MW 7 MW 8 MW 9 MW 13 MW 14 MW 15 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJTDS 1a, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

42 TOTAL DISSOLVED SOLIDS UPPER AQUIFER SHALLOW ZONE 2 of Total Dissolved Solids (TDS) Ambient Screening Threshold (912) 5 MW 2 MW 4 MW 1 MW 11 MW 12 MW 16 MW 17 MW 2 MW 21 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJTDS 1b, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

43 TOTAL DISSOLVED SOLIDS UPPER AQUIFER SUPPLY ZONE Total Dissolved Solids (TDS) Ambient Screening Threshold (713) 5 MW 18 MW 19 MW 22 MW 24 MW 25 MW 29 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJTDS 2, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

44 CHLORIDE UPPER AQUIFER SHALLOW ZONE 1 of Chloride 6 4 Ambient Screening Threshold (239) 2 MW 3 MW 4 MW 5 MW 6 MW 7 MW 8 MW 9 MW 13 MW 14 MW 15 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJCl 1a, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

45 CHLORIDE UPPER AQUIFER SHALLOW ZONE 2 of Chloride 6 4 Ambient Screening Threshold (239) 2 MW 1 MW 2 MW 1 MW 11 MW 12 MW 16 MW 17 MW 2 MW 21 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJCl 1b, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

46 CHLORIDE UPPER AQUIFER SUPPLY ZONE 1 8 Chloride Ambient Screening Threshold (6) MW 18 MW 19 MW 22 MW 24 MW 25 MW 29 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJCl 2, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

47 NITRATE UPPER AQUIFER SHALLOW ZONE 1 of Nitrate 15 1 Ambient Screening Threshold (52) 5 MW 1 MW 2 MW 8 MW 11 MW 13 MW 15 MW 16 MW 17 MW 21 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJNO3 1a, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

48 NITRATE UPPER AQUIFER SHALLOW ZONE 2 of Nitrate 15 1 Ambient Screening Threshold (52) 5 MW 3 MW 4 MW 5 MW 6 MW 7 MW 9 MW 1 MW 12 MW 14 MW 2 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJNO3 1b, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

49 NITRATE UPPER AQUIFER SUPPLY ZONE 5 4 Nitrate Ambient Screening Threshold (34) MW 18 MW 19 MW 22 MW 24 MW 25 MW 29 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJNO3 2, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

50 SULFATE UPPER AQUIFER SHALLOW ZONE 1 of Sulfate 2 Ambient Screening Threshold (128) 1 MW 1 MW 3 MW 5 MW 6 MW 8 MW 9 MW 13 MW 15 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJSO4 1a, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

51 SULFATE UPPER AQUIFER SHALLOW ZONE 2 of Sulfate 2 Ambient Screening Threshold (128) 1 MW 2 MW 4 MW 7 MW 1 MW 11 MW 12 MW 14 MW 16 MW 17 MW 2 MW 21 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJSO4 1b, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

52 SULFATE UPPER AQUIFER SUPPLY ZONE 4 3 Sulfate 2 1 Ambient Screening Threshold (77) MW 18 MW 19 MW 22 MW 24 MW 25 MW 29 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJSO4 2, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

53 CALCIUM UPPER AQUIFER SHALLOW ZONE 1 of Calcium Ambient Sreening Threshold (145) 5 MW 3 MW 4 MW 5 MW 6 MW 7 MW 9 MW 12 MW 13 MW 14 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJCa 1a, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

54 CALCIUM UPPER AQUIFER SHALLOW ZONE 2 of Calcium Ambient Sreening Threshold (145) 5 MW 1 MW 2 MW 8 MW 1 MW 11 MW 15 MW 16 MW 17 MW 2 MW 21 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJCa 1b, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

55 CALCIUM UPPER AQUIFER SUPPLY ZONE 3 25 Calcium Ambient Screening Threshold (18) 5 MW 18 MW 19 MW 22 MW 24 MW 25 MW 29 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJCa 2, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

56 POTASSIUM UPPER AQUIFER SHALLOW ZONE 1 of Potassium (millegram per liter) Ambient Screening Threshold (8.8) MW 1 MW 2 MW 3 MW 4 MW 5 MW 7 MW 8 MW 9 MW 1 MW 13 MW 15 MW 16 MW 17 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJK 1a, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

57 POTASSIUM UPPER AQUIFER SHALLOW ZONE 2 of Ambient Screening Threshold (8.8) Potassium (millegram per liter) MW 6 MW 11 MW 12 MW 14 MW 2 MW 21 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJK 1b, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

58 POTASSIUM UPPER AQUIFER SUPPLY ZONE Potassium (milligram per liter) Ambient Screening Threshold (5) 4 2 MW 18 MW 19 MW 22 MW 24 MW 25 MW 29 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJK 2, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

59 SODIUM UPPER AQUIFER SHALLOW ZONE 1 of Sodium Ambient Screening Threshold (346) 2 MW 1 MW 3 MW 5 MW 6 MW 7 MW 8 MW 9 MW 13 MW 15 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJNa 1a, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

60 SODIUM UPPER AQUIFER SHALLOW ZONE 2 of Sodium Ambient Screening Threshold (346) 2 1 MW 2 MW 4 MW 1 MW 11 MW 12 MW 14 MW 16 MW 17 MW 2 MW 21 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJNa 1b, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.

61 SODIUM UPPER AQUIFER SUPPLY ZONE Sodium Ambient Screening Threshold (133) MW 18 MW 19 MW 22 MW 24 MW 25 MW 29 Note: Proposed thresholds were presented in the June 18, 21 Remedial Investigation Report prepared by JJNa 2, but have not been approved by the CVRWQCB as of the date of this technical memorandum, and as such are provided for comparison purposes only.