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Ge,0kFcd?echnus Inc Page 3 Bndges Specialty Center Report-Groundwater Monitoring Project No 377 2 October 13,1995 3.3 Groundwater Sampling Procedure The groundwater sampling procedure used in this project was as follows, Each well was unlocked, opened, headspace air screened using an Organic Vapor Meter and depth to water was measured from the top of casing As a matter of procedure, the following actions are taken to evaluate the presence of floating product, or third phase contaminant material on the groundwater If field evidence suggests that floating product may be present (i e , the well has a strong odor of hydrocarbons and gasoline is observed on the water meter probe), then either a bailer or product/water interface meter is used to measure the thickness of floating product on the surface of the groundwater In the event that floating product is present, that well would not be sampled unless specifically requested A weighted disposable bailer belayed by a dedicated clean nylon string was used to purge stagnant water from the well Purge water removed from the well was temporarily placed in a graduated container to keep track of removal volume and to monitor for the formation of a sheen Water quality parameters were monitored visually for cloudiness and measured for temperature, conductivity, and pH Three to five well volumes of water was removed from the well prior to sampling and continued until pH, conductivity, and temperature had stabilized (Table 1) to ensure sampling from representative formation water I After stabilization of water parameters, the well was allowed to recharge Prior to sampling the well, a bailer blank was collected by pouring distilled water into the bailer and emptying it into a sample container Sampling was accomplished by slowly lowering the bailer into the well and carefully allowing it to fill with water After filling, the bailer was carefully raised from the well taking precaution not to agitate the contained water The water was slowly transferred into a sample container using a sample transfer device Each sample container consisted of a 1 liter amber glass bottle After assuring that bubbles were not present, the bottle was labeled and inserted into a closed-cell foam holder and placed in an chilled ice chest, for transport to the laboratory A chain of custody document was filled out which listed all samples collected, their date of collection, transfers of custody, and laboratory analyses requested This document is used to track the samples and to ensure their integrity