Laserfiche WebLink
PROBLEM ASSESSMENT REPORT <br /> '— Moore Petroleum, Inc. <br /> 5941 F Street, Banta, CA <br /> NGA Project No. 10-90.481 <br /> Page 5 <br /> TABLE 2 <br /> Well Development Information <br /> Well I.D. Date Volume of Developed Water <br /> - MW-4 6/12/90 15 gallons <br /> 7/06/90 10 gallons <br /> MW-5 6/12/90 35 gallons <br /> 7/06/90 25 gallons <br /> MW-6 6/12/90 10 gallons <br /> 7/06/90 25 gallons <br /> 3.3 Site Soils and Goology <br /> The majority of the site surface is covered by a 2-inch.-thick layer <br /> of asphalt underlain by a 4-inch-thick layer of aggregate base <br /> a., Overlying the USTs, the surface is covered by a 12-inch-thick layer <br /> -- of concrete. Subsurface geology beneath these surface layers, has <br /> been determined by information derived from soil borings drilled <br /> by ETS, Delta, and NGA. Examination of soil boring logs shows the <br /> A site to be underlain primarily-.by strata of sand, clay, silty clay, <br /> silty sand and silt. The uppermost strata which underlies most <br /> of the site, consists clay and/or clayey silt. This layer ranges <br /> from about 13 to. 17 feet in thickness. Underlying this strata is <br /> a layer of sand which appears to grade laterally into silt between . <br /> monitoring wells MW-4 and XW-1. This sand/silt strata ranges in <br /> t1aickness from about 11 feet at MW--3 to about 30 feet at NW-4. <br /> Underlying the sand/silt strata, along the southern boundary of the <br /> .roperty, is a.layer of clay and clayey silt (Figure 5) . 'This unit <br /> appears to grade in a northerly direction (Figure 4) into a layer <br /> of sand (between NW-1 and MW-6) . Subsurface geology at the site <br /> can be more easily interpreted by examination of the geologic <br /> cross-sections presented as Figures 4 and 5. Cross-section <br /> locations are shown on Figure 2. <br /> g.9 8oi1 A��lytiCal Results <br /> T' Soil samples collected during the drilling of monitoring wells MW- <br /> 4, NW-5, and MW-6 were submitted to a California-certified <br /> laboratory and analyzed for those parameters listed in Section 1.2. <br /> Petroleum constituents were not detected in the soil sample from <br /> NW-6, and detected at vary low levels in the samples collected from <br /> ------ MW-4 -and-NW-5.--TPH--was--only-detected -in-the--sample-ftuents-were <br /> a concentration of 2.4 parts per million. BTEX constituents were <br /> detected in the samples from XW-4 and MW-5 at concentrations only <br />