ARCHIVED REPORTS XR0008518 - Laserfiche WebLink

Home Browse Search

Ceofo uaf7ec(tnus Inc Page 3 Work Plan Valentine(Castle Motors) Project No 723 2 April 11,2000 2.3 Groundwater Monitoring Groundwater monitoring is proposed on a quarterly basis for the seven monitoring wells and 1 one domestic well located at 60 E Castle Street Notification will be given to SJC PHS/EHD prior to a monitoring event being performed The procedure for performing a groundwater monitoring event is discussed below. Before sampling is attempted, the well will be sounded for depth to water and then a clear disposable bailer will be used to determine if floating product is present The well will be purged of at least 3 well volumes of stagnant water using either a submersible pump or a stainless steel bailer Purging will continue until the temperature, EC, and pH of the groundwater has stabilized (<10% variation between three readings) indicating that formation water representative of aquifer conditions is entering the well These water quality parameters are measured at intervals of each well volume purged In addition to the normal water quality parameters measured during well purging, pH, conductivity (EC) and temperature, we will measure oxidation-reduction potential (ORP) tA stainless steel or disposable plastic bailer will be used to collect each sample Care will be taken to minimize sample agitation from the initial filling of the bailer to the transfer of the sample to the VOA vials and glass amber liter bottles Once the sample container is filled and capped, the bottle will be inverted, tapped, and checked for headspace bubbles The sample container is identified and labeled with a unique designation, inserted into foam holders and placed in an ice chest cooled to 4°C for transport to the Iaboratory All non-disposable sampling equipment is decontaminated using a steam cleaner before and between uses Disposable gloves will be used by the sample technician while collecting the ' samples and will be changed with each sampling event A bailer blank for each well will be collected prior to sampling by filling the decontaminated stainless steel/disposable plastic bailer with water (provided by the laboratory) and then filling a VOA vial (provided by the laboratory) using the same procedures for actual sample collection ' Bailer blanks for each sample, along with a field blank (prepared from water provided by the laboratory poured into a VOA vial on site), will accompany the samples to the laboratory and ' serve as checks against cross contamination A chain of custody document, listing all samples collected, accompanies the samples from field to laboratory, thereby providing a means to track their movement and insure their integrity All water purged from each monitoring well will be placed in a 55 gallon DOT approved ' container, properly labeled and stored on site 2.3.1 Groundwater Sample Analysis ' The groundwater samples will be submitted to Sherwood Laboratories of Hilmar (State Certified Laboratory #1400) and analyzed for • benzene, toluene, ethylbenzene and xylene (BTEX by EPA method 602) gasoline range petroleum hydrocarbons (TPH-Gas by EPA method 5030/8015m) r the oxygenated fuel compounds (MTBE, DIPE, ETBE, TAME and TBA by EPA method 8260) Continued testing for the oxygenated fuel compounds is warranted at the site as previous rmonitoring events have shown the presence of MTBE, DIPE and TBA r