Laserfiche WebLink
ti <br /> a o EIDPIDOSERVICES, INCORPORATED <br /> MPDS-UNG981-05 <br /> November 18 , 1994 <br /> Unocal Corporation <br /> 2000 Crow Canyon Place, Suite 400 <br /> P O Box 5155 <br /> San Ramon, California 94583 <br /> Attention Mr David J. Camille <br /> RE . Quarterly Data Report <br /> Unocal Service Station ##6981 <br /> 4707 Pacific Avenue <br /> Stockton, California <br /> Dear Mr. Camille <br /> This data report presents the results of the most recent quarter of <br /> monitoring and sampling of the monitoring wells at the referenced site <br /> by MPDS Services, Inc <br /> RECENT FIELD ACTIVITIES <br /> The monitoring wells that were monitored and sampled during this <br /> quarter are indicated in Table 1 Prior to sampling, the wells were <br /> checked for depth to water and the presence of free product or sheen <br /> The monitoring data and the ground water elevations are summarized in <br /> Table 1 The ground water flow direction during the most recent <br /> quarter is shown on the attached Figure 1 � <br /> Ground water samples were collected on October 26 and 27 , 1994 Prior <br /> to sampling, the wells were each purged of between 2 and 14 5 gallons <br /> of water During purging operations, the field parameters pH, <br /> temperature, and electrical conductivity were recorded and are <br /> presented in Table 2 Once the field parameters were observed to <br /> stabilize, and where possible, a minimum of approximately four casing <br /> volumes had been removed from each well, samples were then collected <br /> using a clean Teflon bailer The samples were decanted into clean VOA <br /> vials and/or one-liter amber bottles, as appropriate, which were then <br /> sealed with Teflon-lined screw caps, labeled, and stored in a cooler, <br /> on ice, until delivery to a state-certified laboratory MPDS Services, <br /> Inc transported the purged ground water to the Unocal Refinery located <br /> in Rodeo, California, for treatment and discharge to San Pablo Bay <br /> under NPDES permit <br /> ANALYTICAL RESULTS <br /> The ground water samples were analyzed at Sequoia Analytical Laboratory <br /> and were accompanied by properly executed Chain of Custody <br /> documentation The analytical results of the ground water samples <br /> collected to date are summarized in Tables 3 and 4 The concentrations <br /> of Total Petroleum Hydrocarbons (TPH) as gasoline and benzene detected <br /> 2401 Stanwell Dnve Suite 400 Concord CA 94520 <br /> TEL (510)602 5120 FAX (510)689-1918 <br />