FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

Monitoring Well Installation Work Plan City of Stockton RWCF April 27,2005 Page 2 3.0 MONITORING WELL LOCATIONS AND RATIONALE Two additional monitoring wells are proposed for the Site. The locations and rationale for each monitoring well are described in this section. The proposed monitoring wells are shown on Figure 2. One additional monitoring well is proposed to be located along the south/central margin of the Site, near the intersection of John Turk Road and State Route 4, to monitor elevated ammonia concentrations observed in MW-4. Elevated ammonia concentrations have not been detected in other wells downgradient of the RWCF ponds(MW-3,MW-5, MW-6,MW-7, and MW-16). The second proposed monitoring well will be located in the northeastern portion of the Site in the RWCF parking lot west of and downgradient of, MW-13. The well is designed to monitor nitrate as nitrogen concentrations downgradient of MW-13. Nitrate as nitrogen has not been detected at or above laboratory reported detection limits in the wells upgradient of MW-13 (MW-11, MW-12, and MW-14, with the exception of 0.2 milligrams per liter detected in MW-14 on December 30, 2003), but has been consistently detected in MW-13. 4.0 MONITORING WELL INSTALLATION FIELD PROCEDURES This section includes a description of the site preparation and monitoring well installation,development, surveying, and sampling procedures. 4,1 SITE PREPARATION Condor will prepare monitoring well installation permit applications for submittal to the San Joaquin County Environmental Health Department (SJCEHD). Condor will receive the well installation permits prior to initiating any fieldwork.The proposed monitoring well locations will be marked with white paint and Underground Service Alert (USA) will be notified at least 48 hours in advance of the fieldwork to locate and identify underground utilities in and near the work area. Because companies contacted by USA may not identify utilities past private property lines and into the site, however, it is the responsibility of the property owner to identify any site utilities. Prior to conducting drilling activities, an on-site tailgate meeting will be held with all drilling personnel and Condor representatives in attendance. A site-specific Health and Safety Plan will be discussed with and presented to all personnel for their signatures.. 4.2 MONITORING WELL INSTALLATION PROCEDURES Two shallow monitoring wells will be installed by a California licensed drilling contractor. Each well site will be hand-augured to five feet below ground surface (bgs) before drilling to lessen potential for intercepting utilities. The monitoring well borings will be drilled using a continuous-flight hollow-stem auger. All down-hole drilling equipment will be steam-cleaned prior to use. Drill cuttings and steam cleaning effluent will be discharged on the ground near each well. The monitoring well borings will be drilled to a depth of approximately 15 to 25 feet below ground surface (bgs). The monitoring wells will be constructed with ten feet of four-inch outside diameter, Schedule 40, flush-threaded, machine-slotted PVC screen (0.010-inch slot size). A flush-threaded PVC bottom cap will be placed at the bottom of the screen section in each well. Blank PVC casing will be