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 Mitchell Plant ash storage sites are included in the CCR monitoring program:
- The bottom ash pond and
- The landfill.
Both storage sites are in active use. Mitchell Plant has switched to dry fly ash handling. The fly ash now is stored in a lined landfill.
In 2017, Mitchell Plant provided 627 tons of material from the bottom ash pond for beneficial reuse. Also in 2017, it provided 369,800 tons of gypsum - the CCR material produced through the process to remove sulfur dioxide from the plant’s flue gases - for beneficial reuse.
- 2018 Groundwater Monitoring Report & Statistical Analysis - New
In 2018, APCO continued its groundwater monitoring activities around Mitchell Plant’s coal ash storage sites. We analyzed this data relative to EPA drinking water standards and/or with groundwater protection standards.
Analysis of this data by an independent third party indicates that these coal ash storage sites are not impacting groundwater quality.
- Coal Combustion Residuals Monitoring & Reporting
Kentucky Power completed the first steps in the new groundwater monitoring program under this rule
Kentucky Power 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. Moving forward, we will use these baselines to help determine if our ash storage sites are impacting the groundwater.
It is important to remember that variations in the level of these substances in groundwater are natural and occur for many reasons.
The initial data at Mitchell Plant showed potential groundwater impacts very close to our storage sites. Additional monitoring indicated that these sites are not impacting groundwater quality.
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.
- Alternate Source Reviews
An independent third party completed Alternate Source Reviews for the bottom ash pond at Mitchell Plant. The reviews consider other factors that could impact sampling results as the groundwater passes the CCR storage sites. An alternate source for groundwater impacts was not found for the bottom ash pond.
The plant will continue sampling groundwater at the bottom ash pond to determine any future need for additional monitoring.
- Location Restrictions
The CCR rule established location restrictions for coal ash storage sites. It requires that storage site locations be evaluated regarding proximity to groundwater aquifers, wetlands, fault areas, seismic zones and unstable areas (example: presence of quicksand).
AEP has completed the required review of location restriction for Mitchell Plant’s CCR storage sites. This review found that both CCR storage sites at Mitchell Plant meet all location restrictions.
- Next Steps
- Mitchell Plant will continue to test water from all of these wells twice each year.
- If, in the future, plant owners determine that an ash storage site is impacting the groundwater, we will seek public input as we develop a mitigation plan to address these impacts.
- Bottom Ash Pond