COMPLIANCE INFO_1997 - Laserfiche WebLink

Home Browse Search

City of Stockton French Camp Landfill Groundwater Investigation Task 4 Deliverables No deliverables will be prepared specifically for submittal to the City. Data reports and laboratory QA/QC reports will be developed by the analytical laboratory. All sampling activities will be documented in field log books with chain-of-custody reporting completed in accordance with the established protocol. Task 5 —Analysis of Water Quality Data CDM will present the water quality data obtained during this investigation in a tabular format to clearly summarize the analytical results. In order to compare the interrelationships between the four zones under investigation,surface water,landfill leachate,intermediate groundwater zone, and deeper groundwater zone,Stiff Diagrams will be prepared for each monitoring point. Stiff Diagrams represent the chemical nature of the water(cation-anion relationships) in a graphical format. The diagrams can be compared against each other to assess interrelationships between water bodies. For example,if the landfill leachate Stiff Diagram is similar in shape to the intermediate zone diagram,then it can be concluded that the waters share similar character and are probably interconnected. This could indicate that a release of inorganic constituents has occurred from the site. Detections of VOCs in the downgradient wells would also suggest a release has occurred as defined in Article 5. Statistical analysis will be performed to compare the groundwater quality of the existing wells with proposed wells installed in adjacent locations. The purpose of this analysis is to determine if data from the current monitoring well network can be used on a long-term basis at the site. The results from these wells have been considered suspect because the wells are either screened through the landfill refuse or are screened near the influence of the sloughs. To test whether the data are useable,a statistical comparison can be made between the new wells,which will be installed in discrete zones,to the existing wells. If the results are statistically similar,and the Stiff Diagrams from the wells are also similar,it can be concluded that the wells are sampling the same water zone, and the data can be combined for future analysis. If the results are not similar,then it will be confirmed that the data from the existing wells is suspect and should not be used for quantitative analysis. Task 5 Deliverables Activities conducted under Task 5 will be documented in the Report of Findings described below. Task 6— Report of Findings The primary purpose of the Report of Findings(Report)is to document the activities associated with the groundwater investigation. These activities include the field work consisting of the monitoring well installation and water sampling,and the data evaluation and interpretation. The Report will present an opinion as to whether the landfill is leaking and whether preparation of the engineering feasibility study for corrective action should be performed. This determination requires a sufficient data base for a statistical analysis of the inorganic parameters and the presence of VOC contamination detected in the downgradient wells. CDM Camp Dresser&McKee 6 VMV,5