Coal Combustion Residuals Monitoring & Reporting
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.
Public Service Company of Oklahoma (PSO) recently completed the first steps in the new groundwater monitoring program under this rule. Two Northeastern Plant ash storage sites are included in the CCR monitoring program:
- The bottom ash pond and
- The landfill.
PSO 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 Northeastern Plant show potential groundwater impacts very close to our storage sites. Using appropriate sampling and analysis methods, we found differences in the amounts of boron, chloride, fluoride, pH, sulfate 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, chromium 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 will do additional monitoring and analysis to determine if there are groundwater impacts from our storage sites farther from the immediate area.
We are proactively reaching out and meeting with plant neighbors and community leaders to answer questions about the data collected so far and to discuss next steps.
- PSO will continue to test water from all of these wells twice each year.
- PSO has hired an outside expert to determine whether there are other potential sources of the substances.
- If PSO determines that the ash storage site is impacting the groundwater, we will expand monitoring to show whether there are water quality impacts farther away from the storage site.
- If additional monitoring indicates that changes in groundwater quality are coming from our ash storage sites, we will seek public input as we develop a mitigation plan to address these impacts.
Here’s how PSO conducted the monitoring:
- The bottom ash pond – six wells and
- The landfill – six wells.
Both storage sites are in active use.
Northeastern Plant now uses dry fly ash handling. Fly ash is stored in a lined landfill. The landfill has an “intermediate” liner. The landfill was not lined when it was first built. Northeastern Plant added the intermediate liner and now places all material over the liner.
In 2016, Northeastern Plant provided 43,586 tons of CCR material from the landfill for beneficial reuse.