ARCHIVED REPORTS_XR0012636 CASE 1

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using alurjinum foil, plastic caps, and duct tape, and placed in an iced cooler. The samples were then submitted to a California-certified laboratory for chemical analysis. The soil borings were logged by Alton Geoscience using the -u Unified Soil Classification System. Other characteristics such as color and results of field measurements of combustible gas in selected soil samples were also recorded _ and included in the soil boring lags. Drilling procedures and soil sampling protocol are presented in Appendix C. 3.2 Qzou.,nd wat_pr Monitorina Well Const action Soil Borings P-1, P-2, B-1, and B-2 were converted to Ground Water Monitoring Wells AMW-1, AMW-2, AMW-3, and AMW-4, based - on the results of field observations and previous sampling events. Monitoring Wells AMW--1 and AMW--2 were completed to a total depth of 20 feet below grade, while AMW-3 and AMW--4 were completed to a total depth of 15 feet below grade. Monitoring Wells AMW-1 and AMW-2 were constructed as 4-inch-diameter wells, while AMW--3 and AMW-4 were constructed as 2-inch-diameter wells. The wells were constructed of flush-threaded, Schedule 40, PVC, blank casing and 0.020-inch, slatted PVC easing (screen) . Monitoring well installation and construction procedures and well 1 -' construction details are presented in Appendix D. Ground water was first encountered during drilling at .a approximately 10 to 11 feet below grade in Monitoring Wells AMw-3 and AMW-4. Based on initial water depth encountered and results of previous investigation, the screen was installed from 2.5 feet below grade extending to the total depth of the boring to account for fluctuations in water level. The wells were then completed with blank casing from the top of the screen to approximately 0.5 foot below grade. _. 3.3 Mnnitoriina Wel] _evelopnent__And Sampling Well development and sampling procedures were conducted in accordance with RV QCB guidelines and SJCEHS requirements. Alton Geoscience's general field procedures for well development and sampling are presented in Appendix E. Proper development and sampling of AMW-1 and AMW-2 were performed on April 26, 1990, while AMW-s and AMW-4 were developed and sampled on August 10, 1990. Approximately 10 well casing volumes of water were removed from each well during development. Prior to sampling, each well was _ - - ----- -- ---obs erved_tor--the_presence--of free-f coating_product or sheen._ - J 6 .