Decades of ‘coal combustion residuals’ leached into groundwater
Richmond Power & Light is continuing to clean up and monitor waste from the years when it generated electricity by burning coal, according to a new progress report. Complete containment is expected within this decade.
Substances found in the waste have leached into groundwater at the site but have not been detected in nearby wells used for drinking water. Within the coming year, RP&L is on target to finalize its plan for containing materials at the waste impoundment and for sending stormwater runoff to Richmond’s wastewater treatment plant.
Tony Foster, general manager and CEO, said last week that RP&L “has complied with all of our self-imposed deadlines” for cleanup of the waste, called CCR, for coal combustion residuals.
RP&L has been working to impound the coal ash pile since 2015.
RP&L is now part of the Indiana Municipal Power Agency, a cooperative of 61 cities and towns. The local plant generates electricity only 20 to 30 days a year when IMPA’s system is strained by peak usage.
RP&L has two coal-fired generating units at its Whitewater Valley site, located at 2000 S. U.S. 27, Richmond. Combined, they can produce 100 megawatts of electricity.
Testing at RP&L in 2019 found higher than allowed quantities of potentially hazardous chemicals — molybdenum and lithium — in wells that are part of a monitoring system built to meet requirements of the Indiana Department of Environmental Management (IDEM). Because of a rule implemented in October 2015, the U.S. Environmental Protection Agency (EPA) required RP&L to develop a plan for cleaning up and containing those substances.
The “Fourth Annual Groundwater Monitoring and Corrective Action Report” issued in August 2022 showed results from groundwater testing in September 2021 and March 2022. The report stated that lithium had been found at a higher level than the EPA’s Groundwater Protection Standard (GPS) at three wells in the two tests. The GPS is 0.040 milligrams per liter (mg/L) for lithium; amounts detected in the wells ranged from 0.0772 mg/L to 0.0477 mg/L.
For molybdenum, the GPS is 0.01 mg/L; testing in the same two tests found 0.0116 mg/L at one well.
The substances have not been detected in nearby sources of potable water.
Another testing round is scheduled for March 2023.
In closure actions planned for completion in 2023, RP&L is working with the Richmond Sanitary District to tap into a wastewater line to take rainwater from the impoundment site to the wastewater treatment plant. In addition, the closure plan will specify interim measures “to reduce contaminants leaching from the Impoundment and/or potential exposures to human or ecological receptors.”
An April 2018 closure plan included covering the CCR with a non-permeable clay liner and high density polyethylene membrane, a composite drainage net, 12 inches of soil and a 6-inch layer of vegetation.
It’s anticipated that RP&L will continue to plan for erosion and sediment control next year and then receive permission from the Indiana Department of Environmental Management for closing the impoundment. Once a plan is finalized, in late 2023 or early 2024, RP&L will hire contractors for the construction of structures anticipated as part of the closure. It’s expected that construction will take two to four years.
The CCR is a result of decades of coal ash disposal at RP&L and many other electric utilities.
From the 1950s until October 2015, RP&L pumped coal waste to a 14-acre surface impoundment area. IDEM began regulating CCR sites in the early 2000s. On Oct. 19, 2015, the U.S. EPA implemented a regulation that requires RP&L contain and monitor the site for contamination. RP&L began developing its strategy for federally regulated cleanup at that time. RP&L works with a firm called GAI Consultants Inc. of Homestead, Pennsylvania, in preparing and monitoring the program. RP&L filed the latest report from GAI — “ACM Progress Report Whitewater Valley – November 2022” – last week.
Documents from that process are posted and available to the public on RP&L’s website at www.rp-l.com/RPL-CCR-Rule.php.