WORK PLANS - Laserfiche WebLink

Home Browse Search

16- KLEINFELDER SURVEY The elevation of the top of the PVC casings is usually surveyed and tied into permanent markers, if readily available. Survey is to 0.1 foot for the "x" and "y" coordinates and .01 foot for the "z" coordinate. +�. MONITORING WELL DEVELOPMENT AND SAMPLING �. Monitoring wells are developed after installation. Each well is first sampled with a clear acrylic bailer to visually inspect for hydrocarbon layer or sheen. If no product layer or sheen is observed on the water, the well is developed by surging and pumping. Surging along the screened interval of the well is performed to draw the sediment from the formation into and out of the well, and to set the sand pack. The sediment laden water is airlifted from the well at a rate of between 0.75 and 10 gallons per minute (gpm) depending on recharge rate and casing size. Development continues until the discharge runs relatively clear of fines. Approximately 5 to 10 well volumes are generally removed from each monitoring well. Discharge water is stored in 55-gallon drums and left onsite for later discharge or disposal, depending on laboratory results. After the wells are developed, the aquifer is allowed to equilibrate for 24-48 hours. The ti. wells can then be purged and sampled. During the purging of the wells, field parameters (pH, conductivity, and temperature) are monitored. Samples are collected after the field parameters have stabilized (normally requiring the removal of five well volumes). Water sampling containers are supplied by and prepared by the laboratory. These �. sample containers are immediately sealed after sample collection and placed in an iced cooler. At the end of the day, the water samples are delivered under chain-of-custody to an analytical laboratory certified by the state for the planned chemical analysis. To prevent cross-contamination between wells, all developing and sampling equipment is thoroughly washed in a alcanox solution and rinsed in distilled water or steam cleaned prior to use in the next monitoring well. i.. LW 121-88-1108