ARCHIVED REPORTS XR0011295 - Laserfiche WebLink

Home Browse Search

Geoloywaf'TecFuucs Inc Page 3 Groundwater Monitoring Report • Project No 425 2 November 17, 1997 water level reading was recorded to an accuracy of 0 01 foot In wells where free floating product was suspected, a clear disposable bailer is used to gauge the interface Stagnant water in the well casing was purged using either a Grundfos pump or electronic bailer as recorded m the field logs (Appendix C) The rate of well purging was monitored The wells were purged of at least three casing volumes and until the groundwater parameters (temperature, conductivity, and pH) had stabilized (Appendix Q indicating that water, representative of actual aquifer conditions, was entering the well Groundwater parameter stabilization was characterized by three successive readings within 10% In this case the instrument was not calibrating properly, and pH measurements were not considered reliable Before a sample was collected, the welI's water level was allowed to recharge to at least 80% of it's initial level All water removed from the monitoring wells and not used as a sample, was placed in a 55 gallon DOT (Department of Transportation 17-H) approved container that is properly labeled and temporally stored on-sate A bailer was used to collect each sample Bailer cleanliness was assured by collecting a bailer blank (pouring distilled water through the bailer and collecting it in a VOA vial) prior to collecting the analytical sample Extreme care was exercised whale collecting samples to prevent agitation of the water contained in the bailer Water samples were transferred from the bailer into 40 ml VOA vials preserved with hydrochloric acid using a bottom emptying device which minimizes sample aeration during transfer of the sample All samples were checked for head space bubbles, labeled, inserted into foam holders and placed in an ace chest cooled to 4°C for transport to the laboratory Disposable gloves were worn by the sampling technician while collecting all samples A chain of custody document, listingall collected and their intended samples p analyses, accompanied the samples from field to the laboratory, thereby providing a means to track their movement and insure their integrity 1.3 Laboratory Analyses The groundwater samples collected on September 19, 1997 were delivered to Sherwood Lab (Department of Health Services Certification No 1400), of Hilmar, California, for analysis The samples were analyzed using the following methods o EPA method 602 - BTEX i o EPA method 5030/8015(m) - TPH-Gasoline o EPA method 8260 - Ethanol, Tertiary Butanol, MTBE, DIPS, ETBE and TAME