ARCHIVED REPORTS XR0011061 - Laserfiche WebLink

Home Browse Search

' C,eolagccal7"eekK�cs Inc Page 4 Groundwater Monitonng Report Project No 724 2 May 17,2004 ' distance to the deep well screen in the MW-4/MW-104 well pair is double the distance of the other two well pairs 1.2 Groundwater Sampling Procedure On March 20, 2004, Del-Tech Geotechnical Support personnel arrived on-site, opened the wells and measured the depth to water with an electrically actuated sounding tape The water level reading was recorded to an accuracy of 0 01 foot In wells where free-floating ' product is suspected, a clear disposable bailer is used to gauge the interface No free- floating product was observed during this monitoring event Stagnant water in the well casing was purged using a dedicated Wattera pump as recorded in the field logs (Appendix C) The rate of well purging was monitored The wells were purged of at least three casing volumes until the groundwater parameters (temperature, ' conductivity, and pH) had stabilized (Appendix C) Wells MW-6, MW-7 and MW-110 de- watered before three well volumes were removed This indicated that water representative of actual aquifer conditions was entering the well Groundwater parameter stabilization was characterized by three successive readings within 10% variance Before a sample was collected, the water level was allowed to recharge to at least 80% of the initial level All purge water removed from the monitoring well was placed in a properly labeled 55-gallon DOT (Department of Transportation 17-H) approved container ' and is temporarily stored on-site A dedicated Wattera pump was used to collect each sample Water samples were transferred in a manner that minimizes sample aeration during transfer of the sample into 40-m1 VOA vials preserved with hydrochloric acid All samples were ' checked for headspace bubbles, labeled, inserted into foam holders and placed into an ice chest cooled to 4°C for transport to the laboratory The sampling technician, while collecting all samples, wore disposable gloves A chain of custody document, listing all samples collected and their intended analyses, ' accompanied the samples from field to the laboratory, thereby providing a means to track their movement and ensure their integrity ' 13 Laboratory Analyses The groundwater samples collected on March 20, 2004, were delivered to Sherwood Labs ' of Hilmar, California (certification #1400) for analyses of 1