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Zone 7 Water Agency – Hansen Park Test Well Summary <br />and Production Well Design Recommendations <br />6 Zone 7 Water Agency <br />December 2025 <br />2.4. Zone Sampling <br />Depth-discrete water samples were collected from above each screened interval within the well to <br />characterize zonal water quality. Groundwater samples were collected on June 3, 2025, under pumping <br />conditions. Starting with Zone #1, Pacific Surveys installed a sampling tool into the well to the specified <br />zone to collect samples for analysis. Samples were collected at the depths shown in Table 6. Water <br />samples were collected and handled according to the Testing, Sampling, and Analysis Plan prepared for <br />the project and analyzed for general mineral, general physical, inorganic, and PFOS/PFAS constituents. A <br />summary table of zonal water quality analysis results are in Appendix B. Zonal PFHxS detections are shown <br />in Table 7. <br />Table 6. Zone Sampling Information <br />Sample Zone Sample Depth <br />Zone #1 448 feet bgs <br />Zone #2 518 feet bgs <br />Zone #3 598 feet bgs <br />Zone #4 646 feet bgs <br />Zone #5 726 feet bgs <br />Table 7. Zonal PFHxS Concentrations <br />Sample Zone Concentration (ng/l) <br />Zone #1 2.70 <br />Zone #2 ND <br />Zone #3 ND <br />Zone #4 ND <br />Zone #5 2.53 <br />The maximum contaminant level for manganese is 0.050 mg/l. The zonal concentration of manganese <br />ranged from a low of 0.046 mg/l in Zone #1 (448 feet bgs) to high of 0.24 mg/l in Zone #5 (726 feet bgs). <br />Based on a review of water quality from other wells in the area, manganese is not a constituent of concern. <br />The elevated and variable manganese concentrations seen in the well are likely a result of incomplete <br />removal of drilling fluids during the well development process. It is not uncommon to have elevated <br />manganese levels in monitoring wells and small diameter test wells in areas/depths where manganese is <br />not a constituent of concern due to the limitations of development with these types of wells. The <br />composite (all zones contributing) concentration manganese was 0.045 mg/l. <br />2.5. Flow Survey <br />On June 3, 2025, a spinner survey was performed in the well by Pacific Surveys to quantify the <br />groundwater flow contribution from individual screen intervals under pumping (dynamic) conditions.