ARCHIVED REPORTS_XR0012638 - Laserfiche WebLink

Home Browse Search

r v x� it IN t�a3F�ssap arrF assE93M£N� REPORT Shull O{1 Company 3725 TrwC Boulevard,?racy,Call[ornia r< W Delta Proj-t No.4o-89-012 ,Page 7 Cross-section A-A' traverses from the northwest to the wtitheast corner of the site through monitoring well MW-3,soil borings SB-4 and SB-3,and monitoring well MW-2(Figure 2). Cross- section A-A' is shown in Figure 3. The sites underlain by sandy to silty clay and clayey silt to a depth of 12 to 15 feet. Underlying the finer grained soils are silty sands which were observed to a depth of 21 feet below the ground surface. 1.7 f3raund Watgl: Depths to ground water were measured and recorded in the monitoring wells on September 26 and October 13, 1989. Ground water was observed between 9 and 11 feet below the ground surface.. Al! field measurements and observations are presented in Table 2. The direction of ground water flow was calculated using the ground water elevations on September 26 and October 13, 1989. The i direction of ground water flow on September 26, 1989,before ground water samples were collected was from the south to the north at a gradient of 0.001 foot/foot. A ground water contour map was . The direction of ground water flow on October 13, 1989, generated `inti is presented in Figure 4 was from the southeast to the northwest at a gradient of 0.001 faotJfaot. TABLE 2 l'-•-- Ground Water Level Data Depth to j= Reference Ground Water Ground Water Physical E1 va ' (feet)- fes{below r v i Observations 9.45 88.00 No odor t� MW-1 09-26-89 97.45 9.22 88.23 No odor 10-13-89 9.31 88.14 No odor MW-2 09-26-89 97.45 9.18 88.27 No odor 10-13-89 88.02 No odor MW-3 09-26-89 99.17 11.15 rvo odor 10-13-89 11.00 88.17 l 1,;.l Hydraulic Conductivil.Y -bearing materials were estimated by performing slug tests on Hydraulic conductivity of the water - - -- --- - the three_monitoring wells(mW-1, MW-2,and MW-3), and by grain size analysis of soil samples collected from soil boring SB-8 at depths of 16 and 20 feet within she water bearing matedr- e - with methods presented in Bower and Rice, 1976. The slug test data were evaluated in accordance grain size data were analyzed using equations developed by Hazen (Freeze and Cherry, 1977, and Krumbeun and Monk, 1943). Analysis of the slug test data indicated hydraulic conductivity for the sandy to clayey silts, which were observed at the water table, averaged l8 fee[ per day(Table 3).