ARCHIVED REPORTS XR0011109 - Laserfiche WebLink

Home Browse Search

' GeofogxafTTechmrs Inc Page 2 Groundwater Monitoring Report Project No 724 2 October 18,2000 ' of groundwater under the site was —17 26 feet below mean sea level The water level has risen significantly at the site since October of 1992 Depth to water averaged approximately ' 32 57 feet bgs in the site's monitoring wells Figure 2 is a groundwater gradient map for the September 26, 2000 monitoring event ' Table 1 in Appendix A contains the groundwater elevations and gradients for all events back to the start of this project in October 1992 Groundwater historically flowed predominately ' to the east at an average of 0 0033 ft/ft 1.2 Groundwater Sampling Procedure ' On September 26, 2000, 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 was suspected, a clear disposable bailer was 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) This indicated that water, representative of actual aquifer conditions, was entering the well Groundwater parameter stabilization was characterized by three successive readings within 10% ' Before a sample was collected, the water level was allowed to recharge to at least 80% of the initial level All water removed from the monitoring well and not used as a sample was placed in a 55-gallon DOT (Department of Transportation 17-H) approved container that was properly labeled and is temporally stored on-site The dedicated Wattera pump was used to collect each sample Extreme care was exercised while collecting samples to prevent agitation of the water contained in the bailer Water samples were transferred into 40-m1 VOA vials preserved with hydrochloric acid in a manner that minimizes sample aeration during transfer of the sample All samples were checked for headspace bubbles, labeled, inserted into foam holders and placed in an ice chest cooled to 4°C for transport to the laboratory The sampling technician, while collecting all samples, wore disposable gloves