Laserfiche WebLink
R604 :UPDATE 16 2-23-1993 <br /> INTRODUCTION <br /> This report includes the results of events occurring at this site <br /> since the 15th Update Status Report, from January 13 , to <br /> February 23 , 1993 . <br /> LOCATION <br /> Regal Station 604 (parcel # 139-020-08) is located at 1448 N. E1 <br /> Dorado and Harding Way, Stockton, San Joaquin County, California. <br /> The site is in projected section 2; TIN; R6E; MDR&M at <br /> approximately 14 feet above mean sea level . Initial drilling <br /> (November, 1989) encountered ground water at approximately 32 <br /> feet below sea level (47' below the surface) and flowing in an <br /> east to southeasterly direction, see figures 1, 2 , and 3 . <br /> UPDATE STATUS REPORT #16 <br /> RESULTS - WATER <br /> GROUND WATER GRADIENT <br /> The ground water gradient map, Figure 4, has been produced from <br /> the February 23, 1993 depth to water measurements . These <br /> measurements show a relatively flat ridge shaped gradient flowing <br /> towards the northeast (MW4) and southeast (MW2) . Depth to ground <br /> water measurements show a continual rise in ground water <br /> elevation indicating a recharge event, as would be an expected <br /> result of the current rain season. <br /> TOTAL PETROLEUM HYDROCARBONS <br /> Floating Product: <br /> No floating product has ever been observed in any of the <br /> monitoring wells . <br /> Dissolved Petroleum Hydrocarbons in Ground Water (EPA method 50.30 <br /> TFH as gasoline) : <br /> With the exception of MW5, which contained 160 parts per billion <br /> (ug/L) , dissolved total fuel hydrocarbons, gasoline range, were <br /> below detection limits for wells sampled on December 7, 1992 ( <br /> MW1, MW4 , and MW7) . MW5 has tested below 1 ppm for gasoline <br /> range hydrocarbons since the June 24, 1991 sampling. - All other <br /> wells have tested below 1 ppm gasoline range hydrocarbons since <br /> the March 29, 1992 sampling. This analysis substantiates the <br /> removal of hydrocarbons associated with the ground water and is <br /> evident in comparing the ground water samples obtained on <br /> December 16, 1991 to those obtained on March 5, 1992 and later, <br /> see Table 1 . <br /> Before 'vapor extraction, November 21, 1990, gasoline range <br /> hydrocarbons were detected in MW1 (2 mg/L) , and MWS (31 mg/L) . <br /> page 1 <br />