Laserfiche WebLink
+� Former Manna Pro Site Page 4 <br /> Quarterly Groundwater Monitoring Report <br /> Project No. 207.2 <br /> April 23, 2002 <br /> Extreme care was exercised while collecting samples to prevent agitation of <br /> •- the water contained in the bailer. Water samples were transferred from the <br /> bailer into 40 ml VOA vials preserved with hydrochloric (provided by the <br /> analytical laboratory). All samples were checked for head space bubbles, <br /> labeled, inserted into foam holders and placed in an ice chest cooled to 4°C for <br /> transport to the laboratory. <br /> ` Gasoline contaminated purge & rinseate water generated during the activities <br /> described above was stored in poly drums located on the site. American Valley <br /> Environmental will remove this material prior to the next scheduled depth to <br /> water measuring event. <br /> 2.2 Groundwater Sample Analyses <br /> Groundwater samples were analyzed as follows: <br /> • Total Petroleum Hydrocarbons as Gasoline (TPH-G) by EPA method <br /> 8015(m). <br /> • Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) by EPA method 602. <br /> The detection limits are included in the summary analytical data table(Table 1). <br /> v <br /> Detectable levels of gasoline range petroleum hydrocarbons and/or BTEX <br /> compounds were found in water samples from five of the seven wells that were <br /> sampled. <br /> 2.3 Field Data <br /> V <br /> The Meld data for this groundwater monitoring event are summarized in Table <br /> 1. The level of groundwater has risen a little over 2 feet since the last <br /> groundwater monitoring event completed on December 7, 2001. In December <br /> the groundwater gradient was notably flat, and consequently locally erratic. <br /> w.. As shown in Figure 3, the gradient has returned to its historical norms with a <br /> northeast bearing of flow. The general characteristics of the groundwater <br /> surface do not appear to have been materially affected by the onset of air <br /> �- sparging in February. <br /> Based on the field data obtained in this monitoring event, the overall <br /> groundwater gradient and bearing of flow as determined by a 3-point <br /> calculation from wells MW-4, MW-8 and MW-9 is 0.0013 ft/ft on a bearing of <br /> N840E. This compares with a gradient and bearing of 0.0008 ft/ft on a bearing <br /> of N230W from the December monitoring event. <br /> �. 2937 Veneman Ave.,#B240 Geo-Phase Environmental Inc. Phone (209)569-0293 <br /> Modesto, CA 95356 Fax (209) 569-0293 <br />