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Parcel 3: 0.5 in. water drop= 60 min/in Parcel 4: 1.9 in. water drop= 16 min/in As can be noted,the perc rates are quite variable for each parcel which confirms the variability of the underlying soil structures. The backhoe trench pump-in test calculations demonstrate an avera e acceptance rate (AR) in gals/sq ft/day as follows: ❑ Length of trench= -16 ft @ grade, Hydraulic area= 6 ft ❑ Width of trench= 8 ft @ grade, Hydraulic area=4 ft ❑ Depth of trench= 15 ft from grade, Hydraulic area= 5 ft ❑ Depth of water maintained on the floor of trench= 5 ft ❑ Depth below bottom of trench at periphery of plume=4 ft (est) ❑ Total water volume applied during test= 1000 gals ❑ Extent of water plume area: water surface= 4 ft x 6 ft :. plume area is estimated to be: 12 ft width x 18 ft length= 216 sq. ft. ❑ Acceptance Rate (AR) =total flow absorbed-(area)(time) ❑ AR= 1000 gals_(216 sq. ft.)(4 hrs _24 hrs/day) = 28 gals/sq. ft./day Theoretical Effluent Acceptance: If the bottom 5 feet of a 36 in dia. x 25 ft deep seepage pit accepts effluent at the calculated rate, each seepage pit will initially accept 89 sq. ft. x 28 gals/sq. ft./day= 2487 gals/day. This seepage pit acceptance rate will decline significantly as biomat formation is increased. Since the groundwater is deep in this locale, seepage pits are allowed and are almost always installed. The subject property soils possess virtually no percolative capacity at shallow depths due to the heavy clay soils and the underlying hardpan. This is the reason for not conducting 42 inch deep perc tests. [4] LOCAL GROUNDWATER AND SURFACE WATER INFORMATION The static water table depth,or the zone of saturation is located at approximately 79 feet below grade according to the 1997 "Lines of Equal Depth" published by the San Joaquin County Flood Control District. There is a slight possibility there may be perched water table conditions under the subject property at a higher elevation than the static water level. There is no potential for future septic impact to any surface waters, namely the Angel Lateral, providing applicable distance requirements are followed. The groundwater directional flow appears to be toward the northwest as depicted on the attached "Lines of Equal Elevation" map. Analysis of water obtained from the domestic well which serves the homesite, reveals a nitrate concentration of<1 ppm NO3. The Maximum Contaminant Level(MCL)for NO3 in drinking water is 45 ppm. Therefore, the underlying drinking water aquifers have not been impacted from various nitrate sources. It can be assumed that the recharge for the aquifer(s) that serve this well are not in L Halley Ag research