ARCHIVED REPORTS XR0012675 - Laserfiche WebLink

Home Browse Search

J. H. KLEINFELDER&ASSOCIATES File: 24-2045--2/29:795 fes., December 31, 1986 Page 3 For the protection of the field crew, the PID will also be used to measure the total volatile concentrations in the breathing zone prior to and during the drilling of the soil borings. Total ionizable hydrocarbon readings in excess of 5 ppm above background in the breathing zone will necessitate respiratory protection measures. This procedure requirement will be outlined in a field safety plan for this project. 3.4 monitoring Well Con ru i n The San Joaquin Local Health District generally requires that three presence of ground water monitoring .wells be installed to assess the petroleum hydrocarbons in`Lhe shallow ground watef. An attempt should be made to place one monitcting -well upgradient and two monitoring wells downgradient of the underground storage tank. It is anticipated that the ground water flow is generally to the north-northeast. Permits'lcr the three monitoring wells . should be obtained from the San Joaquin Local Health District prior to drilling. A ground water monitoring well will be constructed in three of the i last soil - borirgs. To preclude introduction of contaminants into the underlying ground water, monitoring wells will not be installed in soil borings where there is a high concentration of petxolewn hydrocarbons. I£ the presence of petroleum hydrocarbons is indicated in the initial soil boring, the next soil boring will be drilled 10 to 20 feet further away from the storage tank. A Eround water monitoring well will be installed only if there is no indication of petroleum hydrocarbons in the soil. Ten�,ative locations for the three ground water monitoring wells are shown €a o;: Plate No. 2. The actual locations of the wells will be selected in the field. Proposed - construction details of the ground water monitoring wells are as follows: o The well casing w.11 be two--inch inside-diameter, flush-threaded joint, schedule 40 PVC pipe. o The wells will be constructed in 8-inch diameter boreholes. o Well screen sections will be perforated with 0.020-inch factory--cut slors. o The screened section may be set five feet above and fifteen feet below depth where ground water is first encountered unless semi-confined or confined aquifer conditions are encountered. o The PVC P_Pe will be steam-cleaned.prior to in,^_tallation. o The annular space between the pipe and the wall of the boring will he. backfilled with clean Lone Star Industries 2/12 Monterey . sand to approximately one foot above the top of the perforated. EM section.