ARCHIVED REPORTS XR0010084 - Laserfiche WebLink

Home Browse Search

Table 1 Monitoring Well Water Levels, con't Well Date Well Depth to Casing Water Floating No Sampled Depth Water Elev Elev Product (ft) (ft) (MSL ft)* (MSL ft) MW-9" 8120197 1595 833 4828 39 95 None MW-9" 12/12/97 1595 800 — 4028 None MW-9^ 3131198 1318 723 — 4105 None MW-9^ 6/30/98 13 18 749 ---- 41 79 None MW-9^ 9129198 1318 876 ----- 3962 None MW-9^ 1114199 13 18 841 -- 39 87 None MW-9^ 4129199 1332 787 — 4041 None MW-9^ 10/5199 1332 871 — 3957 None MW-9" 1/27100 1311 813 ----- 4015 None MW-9^ 4/20100 1309 791 ---- 4037 None I * Casing elevation data from Evan Technologies, Site Investigation Report, April 7, 1992 ^ Casing elevation data from Triple"ET Engineering and Surveying, August 14, 1997 Monitoring for 3rd quarter canceled by PHS EHD The sampler proceeded to purge well volumes of groundwater using a submersible electric purging pump (a volume calculation was done for each well following sounding measurements) Conductivity, pH, and water temperature readings were obtained between each well volume purge, and these were noted on the attached groundwater sampling information sheets Once these readings stabilized after two consecutive purge volumes, aquifer water is assumed to be entering the well When the well recovered to about 80% of the initial water level, the sample was collected Purge water was stored on-site in drums The well sampling information sheets are attached The groundwater sample was collected with a new disposable bailer The groundwater sample was then poured with minimum cavitation into the appropriate, laboratory prepared sample containers leaving no headspace The sample container was then immediately capped, labeled and placed in a chilled ice chest for shipment to Chromalab, Inc in Pleasanton, California (a State Certified Testing Lab) under chain-of-custody documentation Groundwater Contour Map and Flow Gradient A groundwater contour map to a known datum was prepared for the data listed in Table 1 above (see Figure 1) The groundwater flow direction was to the north-northwesterly under a calculated gradient of 0 003 The flow direction is consistent with historic observed trends, and remains relatively flat Overall groundwater levels appear to have dropped slightly from the previous quarter However slightly higher groundwater levels occur near the center of the site, groundwater mounds have formed in this vicinity in the past The nearby canal and on-site imgation line are reported full and leakage from the line could account for these water level changes (see Figure 1)