AES Indiana is moving ahead with plans to address the toxic coal ash ponds at its Harding Street Station along the east bank of the White River.
Coal ash at the site is contaminating nearby groundwater at levels exceeding protection standards, and federal rules require any utilities facing such a situation to formulate plans to clean up the problem. The investor-owned utility recently released an updated third-party assessment that details various ways AES can correctly manage the waste and comply with federal regulations.
Groundwater monitoring beginning in 2019 at the site’s coal ash ponds found high levels of arsenic, lithium and molybdenum at levels that require corrective actions. The pollutants must be cleaned up, but the report by Ohio-based firm Haley Aldrich says they pose “no adverse impacts on human health or the environment.”
While the report outlines many potential solutions, some environmental advocates say there is no silver bullet and that each potential solution will have some drawbacks.
“The bottom line is that we need to stop groundwater contamination and make sure the coal ash is secured the next time the White River floods,” Indra Frank, coal ash advisor with Hoosier Environmental Council, said.
Cleaning up coal ash
AES officials say the company will use certain criteria to determine the most effective way to clean up the coal ash. Potential remedies must protect human health and the environment, protect groundwater, reduce or eliminate future releases of contaminants, and remove the existing contamination.
Once AES identifies solutions that meet the above criteria, it will then evaluate them on their short- and long-term effectiveness as well as how easy each solution will be to implement.
The Haley Aldrich report outlines potential solutions AES can choose from, such as capping the ponds with cement or building walls in the ponds to contain the contaminants and water treatment systems.
AES, as a requirement under the federal coal ash rule, opened up a public comment period so residents and stakeholders can submit their opinions on the proposed solutions. These comments will be considered before the utility chooses what to do.
One option that Frank supports but which does not appear in the report would be containing all the coal ash into one wall-lined pond rather than putting it into multiple ponds as is currently being done.
Coal ash at Harding Street
The Harding Street station began coal-burning operations in 1931 and continued through February 2016 when the facility stopped burning coal. However the ash from the prior decades of burning remains on site.
That ash, also called coal combustion residuals, is stored in multiple ponds, or watery impoundments to the south of the main plant. Coal ash contains, among other things, contaminants such as mercury, cadmium and arsenic that can contaminate waterways, groundwater, drinking water and the air.
The ash stored at Harding Street is deeper than the water table in some places, mixing with the groundwater. The depth of the pond means contaminants in the coal ash are able to mix with the groundwater.
The assessment will help AES focus on two main goals. The first is preventing any more coal ash pollution from reaching the groundwater. The second involves determining what to do with the groundwater that is already contaminated.
AES has created an online portal for the public to write their comments on the coal ash clean up plan. Comments can be entered at aesindiana.com/harding-street-cma-meeting or emailed to aesindianapuvlicaffairs@aes.com. The public can submit comments through Nov. 16
This article was written by IndyStar reporter Karl Schneider.