USEPA Statistical Analysis of Ground-water Monitoring Data at RCRA Facilities – Unified Guidance (USEPA, 2009) and the addendum to that guidance (EPA, 1992) as well as D 6312-98 Standard Guide for Developing Appropriate Statistical Approaches for Groundwater Detection Monitoring Programs. Intra-well monitoring is usually the preferred approach to statistical analysis of groundwater monitoring data as it eliminates the spatial component of chemistry variability from the statistical evaluation. However, intra-well comparisons are appropriate only if it can be demonstrated that wells have not been impacted by site disposal activities. Intra-well is the preferred monitoring strategy when there is: No definable groundwater gradient No pre-existing contamination Too few upgradient wells Radial groundwater flow patterns Low groundwater flow rate (e.g., 50 ft/year) In the semi-annual monitoring reports, the qualified hydrogeologist should assess the potential for sample contamination by examining the results of measurements of the field, lab, and equipment blank samples. It is assumed that any analytes which occur in the field or laboratory, which might add to the concentration of the analyte in the sample, will be picked up by the blank samples and measured. When analytes of interest are found in the blank samples, it indicates the potential contamination of the unknown sample. ASSESSMENT MONITORING Assessment monitoring must be conducted in accordance with 132 Chapter 7 Section 005 if during detection monitoring a statistically significant increase (SSI) over background has been detected and verified for one or more of the detection monitoring program constituents (Figure 1). Examples of assessment monitoring schedule options for a monitoring well are shown in Figures 2 and 3. Conducting assessment monitoring applies to all solid waste disposal areas accepting municipal solid waste, industrial waste, delisted waste and fossil fuel combustion ash. A qualified groundwater scientist or hydrogeologist may propose an alternative monitoring frequency and/or list of parameters based on waste, leachate and site hydrogeologic characteristics in accordance with Title 132 Chapter 7 Section 005.02D and 005.03. Figure Ground Water Monitoring and Remedial Action for Solid – Waste Disposal Areas
USEPA Statistical Analysis of Ground-water Monitoring Data at RCRA Facilities – Unified Guidance (USEPA, 2009) and the addendum to that guidance (EPA, 1992) as well as D 6312-98 Standard Guide for Developing Appropriate Statistical Approaches for Groundwater Detection Monitoring Programs. Intra-well monitoring is usually the preferred approach to statistical analysis of groundwater monitoring data as it eliminates the spatial component of chemistry variability from the statistical evaluation. However, intra-well comparisons are appropriate only if it can be demonstrated that wells have not been impacted by site disposal activities. Intra-well is the preferred monitoring strategy when there is: No definable groundwater gradient No pre-existing contamination Too few upgradient wells Radial groundwater flow patterns Low groundwater flow rate (e.g., 50 ft/year) In the semi-annual monitoring reports, the qualified hydrogeologist should assess the potential for sample contamination by examining the results of measurements of the field, lab, and equipment blank samples. It is assumed that any analytes which occur in the field or laboratory, which might add to the concentration of the analyte in the sample, will be picked up by the blank samples and measured. When analytes of interest are found in the blank samples, it indicates the potential contamination of the unknown sample. ASSESSMENT MONITORING Assessment monitoring must be conducted in accordance with 132 Chapter 7 Section 005 if during detection monitoring a statistically significant increase (SSI) over background has been detected and verified for one or more of the detection monitoring program constituents (Figure 1). Examples of assessment monitoring schedule options for a monitoring well are shown in Figures 2 and 3. Conducting assessment monitoring applies to all solid waste disposal areas accepting municipal solid waste, industrial waste, delisted waste and fossil fuel combustion ash. A qualified groundwater scientist or hydrogeologist may propose an alternative monitoring frequency and/or list of parameters based on waste, leachate and site hydrogeologic characteristics in accordance with Title 132 Chapter 7 Section 005.02D and 005.03. Figure – Ground Water Monitoring and Remedial Action for Solid Waste Disposal Areas
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