In 2015, the U.S. Environmental Protection Agency (EPA) issued a new rule addressing the handling, storage and disposal of coal combustion residuals (CCRs). CCRs are the materials that remain after coal is burned.
Two Conesville Plant ash storage sites are included in the CCR monitoring program:
- The ash pond system and
- The landfill.
Both ash storage sites are in active use. Conesville uses a dry handling system for fly ash and places the fly ash in a lined landfill.
In 2017, Conesville provided nearly 200,000 tons of fly and bottom ash and more than 525,000 tons of FGD materials for beneficial reuse. The plant itself beneficially reused significant amounts of this material for local mine reclamation work.
AEP has announced plans to permanently cease operations at Conesville Plant in mid-2020. At that time, the plant will stop placing material into the pond and landfill and will begin closure activities.
- Coal Combustion Residuals Monitoring & Reporting
AEP has completed the first steps in the new groundwater monitoring program under this rule.
AEP took a series of groundwater samples at the boundaries of both ash storage sites. We took some samples before the groundwater passed beneath the ash storage sites. (The reports refer to this as up-gradient.) We took other samples after it passed beneath the sites (down-gradient). We used the data to establish baseline levels for 21 different substances in the groundwater. It is important to remember that variations in the level of these substances in groundwater are natural and occur for many reasons.
Moving forward, we will use these baselines to help determine if our ash storage sites are impacting the groundwater. We will watch to see whether there are changes in the amount of these substances before and after the groundwater flows beneath the ash storage sites. We also will watch whether levels of these substances vary from the baselines we observed.
The initial data at Conesville Plant show potential groundwater impacts very close to our storage sites. Using appropriate sampling and analysis methods, we found differences in the levels of boron, calcium, chloride, fluoride, pH and total dissolved solids in certain wells before and after the groundwater passed beneath the storage sites. The rule calls these indicator substances. They are used to determine whether additional analysis is needed.
Baseline sampling in some wells showed one or more results for arsenic, barium, beryllium cadmium and radium above primary drinking water standards. One or more samples showing a higher concentration of a substance, even above a standard, does not mean that local drinking water is unsafe or that there is any impact from the ash storage site.
We are working to understand what the numbers mean. We have other wells on the plant site that are not specifically part of this program. We have begun taking samples at these wells to better understand groundwater conditions farther from the ash storage sites. We have installed 12 additional wells and have begun to gather data from them. We are finding much lower levels of arsenic and other substances at all of these wells.
We also know that nearby wells used for public drinking water are tested regularly to ensure they meet drinking water standards.
We proactively reached out and met with plant neighbors and community leaders to answer questions about the data collected so far and to discuss next steps.
Here’s how AEP conducted the initial monitoring:
- The ash pond system - 19 wells and
- The landfill - 28 wells.
- Alternate Source Reviews
Independent third parties completed Alternate Source Reviews for the Conesville ash pond system and landfill. The reviews consider other factors that could impact sampling results as the groundwater passes the CCR storage sites.
This review process found alternate sources for groundwater impacts at Conesville Plant’s landfill site. The plant will continue sampling groundwater at the landfill to determine any future need for additional monitoring.
An alternate source for groundwater impacts was not found for the ash pond system.
- Location Restrictions – New
The CCR rule established location restrictions for coal ash storage sites. It requires that storage site locations be evaluated regarding proximity to
- Groundwater aquifers,
- Fault areas,
- Seismic zones and
- Unstable areas (example: presence of quicksand).
AEP recently completed the required review of location restrictions for Conesville Plant’s CCR storage sites. This review found:
- The Conesville ash pond system is separated from the uppermost aquifer by less than the five feet specified by the rule. It does meet the other four restrictions.
- The Conesville landfill meets all location restrictions.
- Next Steps
- AEP will continue to test water from all of the wells in the groundwater monitoring program twice each year.
- If AEP determines that an ash storage site is impacting the groundwater, we will expand monitoring to find out if there are water quality impacts farther away from the storage sites themselves.
- If additional monitoring shows that changes in groundwater are coming from our ash storage sites, we will seek public input to develop a mitigation plan to address these impacts.
- AEP will begin closure activities for the ash pond system and landfill when the plant ceases operation in 2020.
- Ash Pond