Laserfiche WebLink
1 <br /> TABLE 2 (cont'd. ) <br /> GROUNDWATER STABILIZATION DATA <br /> September 13, 1993 <br /> ' Volume Temperature Conductivity <br /> (gallons) pH__l (°F) (µS/cm x 1000) <br /> MW-5 <br /> ' 0 6. 5 69. 6 1.45 <br /> 1 7 . 0 69. 6 1.45 <br /> i 2 7 . 3 69.9 1.24 <br /> 3 7 .9 73.7 1.47 <br /> 4 8 . 1 71.8 1. 36 <br /> 5 7 . 0 69.4 1.. 35 <br /> 6 3 . 5 69.9 1.29 <br /> 4.0 FINDINGS <br /> ' 4. 1 Stratigraphy <br /> This site is underlain by relatively fine-grained materials in the <br /> shallow subsurface. Clayey to sandy silt is present in the upper 25 <br /> ' to 30 feet; silty clay dominates below this depth. Similarly fine- <br /> grained deposits were reported by WHF Environmental in several <br /> previous assessment reports. The clay and silt are slightly <br /> ' oxidized or reduced, and colors are mostly brownish-gray to bluish- <br /> gray. A more strongly oxidized zone was cored from 30 to 40 feet in <br /> B18 . This zone contains caliche or calcareous nodules from about 35 <br /> ' to 40 feet, forming what WHF Environmental termed "hardpan" . <br /> According to Figures 3 and 4 of WHF Environmental 's Monitoring Well <br /> Installation Report dated November 24, 1992 , the monitoring wells <br /> are completed in a fine-grained sand bed that extends from <br /> approximately 50 feet to more than 65 feet in MW-1, MW-3 , and MW-4 . <br /> This bed was also penetrated in MW-5 but was not sampled. <br /> ' 4.2 Soil Sample Analysis <br /> organic vapors were detected by the PID in all soil samples from <br /> both B17 and B18 during drilling. Vapor readings ranged from 3 to <br /> 1003 ppm (Appendix A) . Several samples emitted odors that resembled <br /> paint thinner or turpentine. There was no evidence of contamination <br /> in any of the soil samples from MW-5. <br /> 9 <br />