Three-Tiered LTMO - Table of Contents

4.2.1   On-post Wells

4.2.2   Off-post Monitoring Wells

4.2.3 Westbay^�-equipped Monitoring Wells

4.2.4   Laboratory Analytical Program

4.2.5   LTM Program Flexibility

Section 5 - Temporal Statistical Evaluation

5.1 Methodology for Temporal Trend Analysis of Contaminant Concentrations

5.2 Temporal Evaluation Results

Section 6 - Spatial Statistical Evaluation

6.1 Geostatistical Methods for Evaluation Monitoring Networks

6.2 Spatial Evaluation of Monitoring Network at CSSA

6.3 Spatial Statistical Evaluation Results

6.3.1 Kriging Ranking Results

Section 7 - Summary of Three-Tiered Long-Term Monitoring Optimization Evaluation

Section 8 - References

Figures

Figure 2.1 Location of CSSA in Bexar County, TX

Figure 2.2 General Site Features

Figure 3.1 Groundwater Monitoring Wells

Figure 3.2 Ground Monitoring Wells and Cross Sections: AOC-65 Area

Figure 3.3 Wells Most Recent COC Concentrations LGR Zone Wells

Figure 3.4 Most Recent COC Concentrations CC Zone Wells

Figure 3.5 Most Recent COC Concentrations BS Zone Wells

Figure 3.6 Most Recent COC Concentrations AOC-65 Area N-S Cross Section

Figure 3.7 Most Recent COC Concentrations AOC-65 Area W-E Cross Section

Figure 4.1 Qualitative Evaluation Recommended Sampling Frequencies - LGR Zone Wells

Figure 5.1 PCE Concentrations through Time at Well CS-16-LGR

Figure 5.2 Conceptual Representation of Temporal Trends and Temporal Variations in Concentrations

Figure 5.3 Conceptual Representation of Continued Monitoring at Locations Where No Temporal Trends in Concentrations is Present

Figure 5.4 Temporal Decision Making Flow Chart

Figure 5.5 PCE Mann-Kendall Temporal Trends in LGR Zone Wells

Figure 6.1 Idealized Semivariogram Model

Figure 6.2 Impact of Missing Wells on Predicted Standard Error

Figure 6.3 Geostatistical Evaluation Results Showing Relative Value of Spatial Information on Total COC Distribution LCR Zone Wells

Figure 6.4 Geostatistical Evaluation Results Showing Relative Value of Spatial Information on Total COC Distribution North to South Cross Section

Figure 6.5 Geostatistical Evaluation Results Showing Relative Value of Spatial Information on Total COC Distribution West to East Cross Section

Figure 7.1 Combined Evaluation Recommended Sampling Frequencies - LGR Zone Wells

Figure 7.2 Proposed Drilling Locations Based on Uncertainty and Qualitative Analysis

Tables

Table 3.1 Current Groundwater Monitoring Program

Table 3.2 Summary of Occurrence of Groundwater Contaminants of Concern - All Results

Table 3.3 Summary of Occurrence of Groundwater Contaminants of Concern - LGR Wells

Table 3.4 Summary of Occurrence of Groundwater Contaminants of Concern - On-Post Open Bore Hole Wells

Table 3.5 Summary of Occurrence of Groundwater Contaminants of Concern - CC Zone Wells

Table 3.6 Summary of Occurrence of Groundwater Contaminants of Concern - BS Zone Wells

Table 3.7 Summary of Occurrence of Groundwater Contaminants of Concern - Off-Post Open Borehole Wells

Table 3.8 Summary of Occurrence of Groundwater Contaminants of Concern - Westbay and AOC-65 Wells

Table 4.1 Monitoring Network Optimization Decision Logic

Table 4.2 Monitoring Frequency Decision Logic

Table 4.3 Qualitative Evaluation of Groundwater Monitoring Network

Table 5.1 Temporal Trend Analysis of Groundwater Monitoring Results

Table 6.1 Best-Fit Semivariogram Model Parameters

Table 6.2 Results of Geostatistical Evaluation Ranking of Wells by Relative Value of Total COC Information in the LGR Zone

Table 6.3 Results of Geostatistical Evaluation Ranking of Wells by Relative Value of Total COC Information in the LGR Zone in the North to South Vertical Cross Section

Table 6.4 Results of Geostatistical Evaluation Ranking of Wells by Relative Value of Total COC Information in the West to East Vertical Cross Section

Table 7.1 Summary of Long-Term Monitoring Optimization Evaluation of Current Groundwater Monitoring Program

Table 7.2 Summary of Revised and Original Monitoring Program