COMPLIANCE INFO_1997-1998 - Laserfiche WebLink

Home Browse Search

City of Stockton Draft Amended Report of Waste Discharge(AROWD) Austin Road Landfill Work Plan The rig and the hollow stem augers will be decontaminated following the procedures in Section 2.2.2 prior to drilling the first boring and after each boring is completed. The washdown will be performed at the on-site decontamination facility. Groundwater Sampling Depth discrete groundwater samples will be collected at the specified aquifers in the borings of each transect using a Hydropunch®sampler. The Hydropunch®is a stainless steel sampling device which is hydraulically driven ahead of the hollow-stem augers into undisturbed soil at a sufficient distance to perform groundwater collection(11h-2 feet). For sample collection,the Hydropunch®is fitted with a dedicated stainless steel tip which seals the bottom opening of the sampler during advancement and then releases as the sampler is retracted to expose a screened opening. After the sampler is retracted about one foot,groundwater enters an internal chamber through a synthetic,reed-type check valve. After a waiting period sufficient to allow the internal chamber to fill(field judgment will be used to expedite this process),the sampler is retrieved. At the ground surface,sampled groundwater will be transferred from the internal chamber to volatile organic compound (VOA)sample vials as described in Section 2.2.1.5. Results from VOC sampling will have a 24-hour turnaround. QA samples will be taken as prescribed by EPA guidance. The Hydropunch®sampler will be decontaminated prior to its next use as described in Section 2.2.2. Aquifer Soils by Split-Barrel Core Samplers Soil samples will be collected using 5-foot long,split-barrel core samplers on the initial borings of each transect. The split-barrel samples will be collected continuously from approximately 10 feet above the water table(at depths starting approximately 90 to 100 feet below ground surface) and extending down to approximately the total depth of 180 feet. The field geologist will open the sampler,log the lithology,and retain the samples in heavy-duty,zip lock baggies. The samples will contain soil of similar lithology over approximately 1-ft depth intervals. These samples will then be labeled with the sample location and depth interval. The split-barrel samplers will be advanced at the same time as the drill hole to collect relatively undisturbed samples(except for the first 1-2 feet which will be advanced through the material previously disturbed by the Hydropunch®groundwater sampler). Lithologic observations will be recorded on boring logs by the onsite geologist. The Unified Soil Classification System (USCS)will be used to describe lithologies,and symbols will be consistent with those used previously by CDM at the French Camp Landfill. 2.2.1.3 Monitoring Well Installation After completion of the Hydropunch®program delineating the edge of the contaminant plume,two monitor well clusters will be installed at the approximate locations depicted in Figure 2. These wells will be completed in the shallow and deep aquifer zones,installed utilizing the air rotary/casing hammer drilling technique. The drilling will be performed as described below and in accordance with procedures described in Section 8.1.6.1.8,Air Rotary Method,of EPA(1987). W:\REPORTS\STOCKTON\AUSTIN\WORKPLAN.DOC Page 6