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SSS§ 6.3. On May 16, 2007, the two perc test borings were drilled in the referenced locations. The sidewalls of each boring were scored with a pry-bar to open potentially smeared sidewails. Two inches of fine gravel was placed at the bottom and three-inch perforated PVC pipe was inserted in each test boring. On May 17, 2007, each boring was pre-saturated with water at 3x each bore hole volume at 0900 hrs, 24 hrs before the start of testing. This pre-saturation exceeds EHD Standards. i SSS§ 6.4Z, 6.5. On May 17, 2007,percolation testing commend :-No st ding water was observed after the 24-hr soak period in either of the two test borings. Contequent , EHD Pere Test Procedure #2 was conducted in which testing was done over a four-hour peri o induce maximum soil saturation. The test results indicate equal perc rates between the 24 inch and 40 incherc test depths, rl 9.2 p p minutes per inch (min/in). A summary of the perc test results with corresponding applicati n rat in gallons of effluent accepted per square foot of soil,per day are found in Table 2: TABLE 2 PER_COI,ATIONTEST RESULTS 70 AREAWITH °y ' RRN� ESPONDING PP (GAL COI�ETIDAY .< � Q:�� 24 INCH DEEP PERC TEST BORING inch 1 0.671 gallonslft2/day PERCOLATION RATE 1 APPLICATION RATE 40 INCH DEEP PERC TEST BORING 19.2 inch 1 0.671 gallons/ft/day PERCOLATION RATE/APPLICATION RATE Application Rate adapted from California State Water Resources Control Board Guidelines for Design o emge Systems and is based on the Perc Rate. D. GROUNDWATER INFORMATION NLS§ 2.1, SSS§ 4.1'. g q Groundwater depths and elevations throu hout San Joa uin CountY<are illustrated on maps published by the County Flood Control and Water Conservation District. However, due to the high degree of variability in groundwater elevations in the Tracy area, groundwater lines of equal depth and equal elevation are not drawn for this area. The last map denoting lines of equal elevation for the Tracy area was published in 1992, and show the general groundwater flow to be in a northeasterly direction, toward the San Joaquin River. This is regarded as the generalized groundwater directional flow,based on highly accurate groundwater studies at the Tracy Defense Depot. Well logs were found in EHD files for surrounding domestic wells, so well construction details and underlying lithology could be determined. Subsurface lithology illustrate intervening strata of sand and clay. NLS§ 2.2, 3.1, SSS2. ,4.2. Since surrounding properties have been intensely farmed for several decades, the potentia or nitrate contamination in the underlying groundwater is y significant. This was d o stra d with the nitrate test results for the water to e (71 ppm) nd for,/ the on-site domestic w 11 (5$ ppm) 5 Chesney Consulting