WORK PLANS - Laserfiche WebLink

Home Browse Search

3 }PJ File No. 20-3937-01 June 21, 1996 _ A-4 GROUNDWATER MONI'CQBING A-4.1 Water Level Measurements Water level measurements are made in the wells prior to purging and sampling the wells. Measurement protocol is as follows: 1. The wells are opened and allowed to equilibrate with the atmosphere. 2. The water level probe is decontaminated in a trisodium phosphate wash, followed by a distilled-water rinse,prior to use in each well. 3. Water level measurements are made using a conductivity-based water-level meter. Depth-to-water is generally measured from a surveyed mark. on the north rim of the PVC well casing. The water level measurements are converted to elevations using the surveyed casing elevations. A-4.2 Groundwater Sampling Groundwater samples are. collected rfrom.the-monitoring rwells at the site. The sampling protocol for each Well is as follows: ` 1. Down-well equipment (pumps, bailers, etc.) is decontaminated by steam cleaning, or by scrubbing in a trisodium-phosphate wash followed .by a distilled water rinse, prior to use in each well. Bailer cord is replaced prior to use in each well. 2. The depth-to-water is measured using a conductivity-based water-level meter. t 3. The volume of water standing in the well is calculated by subtracting the depth-to-water measurement from the depth'of the well and multiplying by the appropriate conversion factor(3.14 *radius2). 4. Three to five well volumes of water are purged from each well using a submersible pump, bladder pump, or Teflon bailer. 5. Physical parameters (pH, electrical conductivity, and temperature) are monitored for stability during purging.' The physical parameter measurements are recorded on purge-and-sample logs, along with the-time and volume of water purged at each measurement. 20-3937-011UP960068 Page A-5 01996,Kleinfelder,Inc. KLEINFELDER 2825 East Myrtle Street,Stockton,CA 95205-4794 (209)948-1345 (209)948-0621 fax