CORRESPONDENCE_1984-1989 - Laserfiche WebLink

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-2- clay-lined, at the site of the present WMU-D (Figure 2) . The ponds were 10 feet deep and totaled about 2 acres. The oil industry related waste placed into the ponds consisted of drilling muds, fluids, and brines. Some fuel oil wastewater was discharged to the ponds. During the spring of 1984, the ponds were cleaned, and the dried sludge and contaminated soil was excavated to a depth of one foot beneath the ponds and placed into Trench 4 of WMU-A. Removal reportedly was completed during October, 1984. WMU-A received a small amount of hazardous waste in the form of contaminated soil from site clean-ups containing solvents, arsenic, chromium, copper, lead, pesticides, fuel oil, waste oil, vanadium catalyst ..waste, paint pond sludge, and empty crushed pesticide, oil, and resin containers. This included sludge and contaminated soils from the clean-up of the five ponds. The last waste was discharged in October, 1984. A temporary earthen cover was placed over WMU-A. The facility submitted the Closure Plan for WMU-A in September, 1987 . After review of this plan by RWQCB and DHS, a Notice of Deficiency was sent to Forward, Inc. to request additional information for the closure. The additional information was submitted in April, 1988. After review of the Closure Plan and addendum to the Closure Plan with response from RWQCB, a Closure Plan package was compiled. The Closure Plan package, as presented, includes the Closure Plan, addendum to closure, submitted by Forward, and additional conditions imposed by DHS. Closure Plan Description The closure of this facility will consist of an engineered cover system for the hazardous waste landfill unit and a groundwater and vadose zone (water bearing zone above groundwater) monitoring system. The engineered cover system is designed to nearly eliminate water movement into the subsurface and to eliminate the contact of surface water with the waste. The cover system will consist of four components: the foundation layer, the clay liner, the vegetative/drainage layer, and the culvert drainage system. The foundation layer will bring the temporary cover up to a minimum 3% grade to insure maximum drainage and minimum run-off. The foundation layer will be made of native and foreign soils, free of debris and cobbles, that will be compacted to prevent settling.