COMPLIANCE INFO_1997-1998 - Laserfiche WebLink

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City of Stockton Draft Amended Report of Waste Discharge(ARO WD) Austin Road Landfill Work Plan ■ Artificial recharge or discharge(e.g,precipitation,infiltration,groundwater discharge to local streams,well withdrawals from EW-1 and EW-2 and local residential wells). ■ Nonhomogenous and anisotropic aquifer hydraulic properties. ■ Estimating present contaminant extent based upon the observed groundwater quality at permanent and temporary monitoring points. ■ Characterizing contaminant fate and transport in the shallow and deep aquifer horizons. 3.0 Deliverables Results of the modeled water flow and plume migration will be depicted in multicolor maps in both plan view and in cross-section. Soil and VOC data will be mapped directly in the site plan for both the deep and shallow aquifer layers. Pumping test results will be presented in tabular form with the aquifer characteristics developed from the tests(transmissivity,aquifer porosity,hydraulic gradient, and areal recharge rate)provided in a separate table. 3. 1 Technical Memorandum jA technical memorandum documenting the field activities and data analysis procedure will be prepared. It will serve as a Report of Findings establishing the refinement of the conceptual model of contaminant fate and transport. The memorandum will be incorporated into the Engineering Feasibility Study as reflected in the schedule in Section 5.0. 3.2 Engineering Feasibility Study/Remediation System Design Documents The Engineering Feasibility Study(EFS)will be prepared in accordance with Article 5 and submitted as depicted in the attached schedule. 4.0 Preliminary Identification of Alternatives The requirements of the plume investigation were established based on the data gaps identified during the development of the site conceptual model. The field program results in collecting information which will fill these data gaps. The other element which defines the plume investigation is an understanding of the range of corrective action alternatives which will be evaluated during the feasibility study phase of the project. It is important that sufficient data is collected during the investigation to support the evaluation of clean-up alternatives. For this reason, a preliminary list of corrective action measures is provided in this Work Plan. Alternative 1—"Continued Existing Corrective Action Program". This alternative at the ARL reflects the existing situation of two extraction wells,on-site treatment,and plume monitoring. The current situation is usually included in a feasibility study to establish a baseline condition against which the other alternatives are measured. Alternative 2—"Wellhead Treatment'. This alternative will eliminate the human health risk exposure pathway,by providing wellhead treatment or alternative water supplies to the residential and other(such as California Youth Authority)wells which may be impacted by the VOC plume. W:\REPORTS\STOCKTON\AUSTIN\WORKPLAN.DOC Page 15