Coal Combustion Residuals Groundwater Compliance & Monitoring

TRC provided strategic advisory services for CCR groundwater compliance and managed the implementation of the CCR Rule for groundwater monitoring.



Confidential Midwest Client

Project Location


The client’s five coal-fired power plants have historically used impoundments/landfills to contain their Coal Combustion Residuals (CCR). Over 10 of the CCR units are regulated under the Federal CCR Rule and are required to perform groundwater monitoring. Four of the units are also subject to state-required monitoring, corrective action, and reporting. The client’s objectives are to:

  • Collect groundwater samples representative of background groundwater quality data from over 150 monitoring wells.
  • Manage and evaluate background groundwater sampling data in accordance with 40 CFR 257.93.
  • Initiate a detection monitoring program in accordance with 40 CFR 257.94.
  • Investigate data that may result in statistically significant increases (SSI), and determine if the SSI may be from a non-CCR source.
  • Develop and submit initial annual groundwater monitoring and corrective action reports in accordance with 40 CFR 257.90(e).
  • Collect and evaluate groundwater, pore water, and surface water
  • data to support state compliance.


During 2017, TRC managed the groundwater monitoring program, coordinated with subcontractors, collected background groundwater quality data from the monitoring wells, managed the data in EQUIS®, performed data QA/QC, developed preliminary and final statistical evaluation plans using groundwater data following the RCRA Unified Guidance, and evaluated groundwater data trends. TRC developed conceptual site models (CSMs) for each site to support management decisions related to impoundment
closures and longer term risk management. TRC is also supporting compliance with state requirements, including evaluating groundwater data to determine the potential need for corrective action under the
state cleanup program.

Background data collection was completed by October 17, 2017, with the groundwater monitoring well networks and planned statistical evaluation certified by a professional engineer. TRC is developing statistical evaluation plans for each unit in accordance with the performance standards of the CCR Rule. Groundwater data collected after October 1, 2017 will be evaluated to determine if an SSI is observed; the initial annual groundwater monitoring report is due on January 31, 2018.

TRC is also evaluating groundwater quality and geochemical indicators to ascertain the potential for SSI’s to occur and making recommendations for additional data gathering activities to support alternative source demonstrations (ASDs) if needed.

See related services

Coal Ash Management

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