Overview (40 CFR 257.90)
The CCR Rule requires that owners of all CCR landfills, CCR surface impoundments and lateral expansions of CCR units install certified groundwater monitoring systems, develop and establish a groundwater sampling and analysis program, begin a detection monitoring plan, and analyze the data collected for the presence of hazardous constituents and other groundwater monitoring parameters. Existing CCR landfills and surface impoundments must demonstrate compliance with these requirements by October 17, 2017. New CCR landfills and surface impoundments must be in compliance with these requirements prior to the initial receipt of CCR into the CCR unit.
Additionally, an annual groundwater monitoring and corrective action report is required for all CCR units. The annual report must document groundwater monitoring activities and corrective actions over the previous year, as well as project activities for the upcoming year. For existing CCR landfills and existing CCR surface impoundments, the initial report is to be complete no later than January 31, 2018, and annually thereafter. For new CCR landfills, new CCR surface impoundments, and all lateral expansions of CCR units, the owner or operator must prepare the initial report no later than January 31 of the year following the year of CCR unit establishment, and annually thereafter.
Groundwater Monitoring Systems (40 CFR 257.91)
A groundwater monitoring system (individual or multiunit) must be installed for all CCR disposal units to yield groundwater samples from the uppermost aquifer that accurately represent the quality of background groundwater and the quality of groundwater passing the waste boundary of the CCR unit. The system must be certified by a qualified professional engineer and include a minimum of one upgradient and three downgradient monitoring wells.
Once a groundwater monitoring program has been established, groundwater monitoring and (if necessary) corrective action must be conducted throughout the active life and post-closure care period of the CCR unit.
Groundwater Sampling and Analysis Requirements (40 CFR 257.93)
A groundwater sampling and analysis program must be developed for all CCR units that includes procedures for sample collection, preservation and shipment, analysis, chain of custody and quality assurance/quality control. Sampling procedures vary according to specific phases of monitoring (detection, assessment and corrective action). Total recoverable metals concentrations must be measured in assessing groundwater quality and samples may not be field-filtered prior to analysis.
Detection Monitoring (40 CFR 257.94)
Detection monitoring must be conducted for all constituents listed in Appendix III at least semiannually during the life of the CCR unit. For existing CCR units, at least eight independent samples must be collected from each background and downgradient well and analyzed for all Appendices III and IV constituents. Evaluation of groundwater monitoring data for statistically significant increases must begin by October 17, 2017. For new CCR units and lateral expansions of existing CCR units, at least eight samples must be collected from each background well and analyzed for Appendices III and IV constituents during the first six months of sampling.
Assessment Monitoring (40 CFR 257.95)
If statistically significant increases over background levels for one or more of the constituents listed in Appendix III are found in downgradient wells during detection monitoring, an assessment monitoring program must be established. During this phase, samples from downgradient wells must be analyzed for all Appendix IV constituents within 90 days of triggering the assessment monitoring program, and annually thereafter.
Within 90 days of obtaining the results from the initial and subsequent sampling events during assessment monitoring, and at least semiannually thereafter, resampling and analyses for all constituents in Appendix III and previously detected constituents in Appendix IV must be conducted for all wells.
If the concentrations of all constituents listed in Appendices III and IV are shown to be at or below background values for two consecutive sampling events, the owner or operator may return to detection monitoring of the CCR unit. The owner or operator of the CCR unit must also establish a groundwater protection standard for each Appendix IV constituent detected.
If a constituent in Appendix IV is later detected at levels above the groundwater protection standard, at least one additional monitoring well must be installed and sampled at the facility boundary in the direction of contaminant migration. Notification must also be given to all neighboring persons who own or reside on land that directly lies over any part of the contamination plume.