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CONCLUSIONS AND RECOMMENDATIONS In summary, the soil conditions examined near the proposed septic disposal area for the new home on the Site were found to be suitable for a septic system. A satisfactory soil percolation rate of 9.62 min/in was observed in the shallow soil zone at the test location. The soil in the test location was found to be clay. Based on maps of recent aquifer levels, the depth of ground water is approximately 60 to 85 feet below ground surface. Ground water flowed generally to the north or northwest in the area at a rate of approximately 24 feet per mile in the fall of 2024; the gradient could not be calculated for the spring of 2025. Live Oak collected a water sample from the domestic well on the Site on March 2, 2026. Nitrate was detected in the water sample at a concentration of 3.2 mg/L-N, well below the MCL of 10 mg/L-N. DBCP was not detected in the sample. Based on the methods and assumptions described, the nitrate loading calculation indicates that the existing and proposed future on-site septic drain field systems have the potential to cause a buildup of nitrate in the aquifer up to 11.9 mg/L-N, slightly over the MCL of 10 mg/L-N. It should be remembered that the Hantzsche and Finnemore equation is a conservative method for determining potential impacts. Ground water is relatively deep in the area, the clay soils may serve to limit the transportation of nitrate to the aquifer, and the on-site domestic well is not showing nitrate impacts from the existing home. Consequently, the actual nitrate loading experienced on the Site over time may be less than predicted. Although Live Oak cannot make engineering recommendations, we are aware that the San Joaquin County Environmental Health Department often allows the use of standard septic systems with oversized septic tanks in cases where a 30 percent reduction would bring the nitrate loading under the MCL; the subject Site's nitrate loading result meets this criterion. Future septic system construction should follow the San Joaquin County On-Site Wastewater Treatment Systems Standards (2017) where applicable. In this area, only shallow septic systems utilizing leach lines or filter beds are typically permitted. LOGE 2612 Page 14