CORRESPONDENCE_1971-1981 - Laserfiche WebLink

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H n 11 8. GEOTECHNICAL DATA Two previous geotechnical reports have been prepared for the Forward Inc. 157 acre operation. The geotechnical data contained in these reports involving geology, faults and seisi city, groundwater conditions, basin recharge, ground- water movement, irrigation water supply, water quality, drainage and flood protection, field exploration and laboratory testing and their related exhibits in the two reports are made by reference part of this report. The referenced reports are: • "Geoteol'uiical Investigation and Waste Management Studies, Proposed 150 Acre Class II -1 Disposal Site, Stockton, Californiaby &=n, dated July 7, 1972. • "Report of Site Information, Austin Road Resource Recovery and Disposal, San Joaquin County, California for Forward, Inc.", Beta Associates, dated April 28, 1978. Both reports are on file with agencies approvinq the permits for the Forward Inc. operations listed on the first page of this report. The geotechnical consulting firm of J. H. Kleinfelder and Associates has reviewed the two reports and their own geotechnical data for the site, current existing data and conditions and determined that the majority of the underlying soils are relatively impermeable (10-6 to 10-8 centimeters per second) and the ground water tables is at a sufficient depth (75-90 feet below existing ground surface) to minimize contamination by leachate. A copy of their findings is made a part of this report and is included in the report appendix. The County Flood Control District monitors wells in the area and provides a bi-annual report and ground water depth maps. A self -monitoring program will be developed in cooperation with the Regional Water Quality Control Board and County engineering and Flood Control personnel. The purpose of the monitoring program will be to develop data to detect migration of potential pollutants outward or downward from the landfilled area. A review of Federal Insurance Rate maps show the proposed site is subject to flooding of 100 year return frequency in -the flood plain of the Littlejohn Creek and along tne, south boundary line of the south area. Neither of these areas pose a flood threat to the landfill operations. The channel area of Littlejohn Creek will not be utilized for landfill operations and the 100 year flood will be contained within the creek banks. The minimal sheet type flood of 100 year return frequency along tho south boundary line would oe less than one foot deep and would not extend more than a few feet into the property. This problem can easily be mitigated by a low perimeter berm within the 50 foot buffer zone. The flood statement letter from the Flood Control District is included in the appendix section of this report. Ll