SU0006059 SSNL - Laserfiche WebLink

Home Browse Search

TABLE 4 AVERAGES OF EAST AND WEST PERCOLATION TEST RESULTS CORRESPONDING APPLICATION RATE AVERAGES 24 INCH DEEP PERC TEST BORING PYFRCOLATION RATE / INFILTRATION RATE PERCOLATION RATE/APPLICATION RATE 34.#min/inch / 0.544 gallons/ft'/day 36 INCH DEEP PERC TEST BORING 19.2/min/inch / 0.769 gallons/ft'/day PERCOLATION RATE/APPLICATION RATE ` / 42 INCH DEEP PERC TEST BORING 14.$ min/inch / 0.686 gallons/ft'/day PERCOLATION RATE/APPLICATION RATE / 60 INCH DEEP PERC TEST BORING PERCOLATION 81min/inch 1 0.908 gallons/ft'/day RATE/APPLICATION RATE J AVERAGE SOIL PROFILE PERC RATE: 24"-60" 19.2 min/inch / 0.727 gallons/ft'/day AVERAGE SOIL PROFILE APPLICATION RATE: 24"-60" D. GROUNDWATER INFORMATION NLS§.1. Groundwater depths and elevations throughout San Joaquin County are illustrated on maps pub 'shed by the County Flood Control and Water Conservation District. However, due to the hi egree 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,primarily based on highly accurate groundwater studies at the Tracy Defense Depot. SSSi 2. . The site has been under agricultural production for the last several decades,but has not farm or the last five years. This may explain why the soil nitrate-nitrogen and soil organic matter concentrations were comparatively low. NLS'2. 33. , SS 4.2. As noted in the Prim gpory the underlying water table has been impact with nitra almost 2x the MCL at 88 p Since there are no septic systems upgradient to the sample location, and the s is s ems nearby can be considered crossgradient, this nitrate source can almost assuredly be associated with agricultural inputs, such as nitrogen fertilizers, in addition to natural nitrate formation. Decomposition of crop residues has probably also contributed to nitrate production through mineralization and nitrification. NLS2. , SSS§L3,4.4 . There are no domestic or irrigation wells on the property. TgsL,j results r the nitrate concentration of the water table, as discussed above are found on Page 9 of / the Primary Report. The domestic well location for the Multipurpose Building, and subsequent Church development is unknown as of the date of this Report. Proper setbacks for a publi!:j ll must be followed. The well location should be installed to the south of the proposed fi area which would place the well upgradient to the disposal area. Page -7- Chesney Consulting