EVANSVILLE — Initial water quality testing has detected some contamination of groundwater around Vectren's coal ash disposal sites at both its power plants.
However, company officials say it's too early to tell how serious any contamination may be or even if it is attributable to the ash ponds.
Contaminants detected in the initial round of federally-required water testing included boron, which is often linked to coal ash. Other detected contaminants included calcium, chloride, fluoride and sulfates.
Detection of the contaminants does not mean any water quality standards are being violated, public drinking water threatened or that there is a health risk, said Angela Retherford, Vectren vice president of environmental affairs.
The disposal sites, which include several ponds and a landfill for scrubber waste, are slated to close as the Evansville-based utility company transitions to natural gas and solar power.
The sites are located at Vectren's A.B. Brown power plant in Posey County and F.B. Culley power plant in Warrick County, adjacent to Alcoa.
Retherford said it was not surprising some contamination was detected. She said data for the initial monitoring is still being studied. She said monitoring to assess levels of specific contaminants and determine how to address it will be finished by the end of this year.
The information is included in initial reports released as electric utilities nationwide comply with the timeline for meeting the requirements of a U.S. Environmental Protection Agency rule regulating the disposal of coal combustion wastes from coal-fired power plants.
Coal combustion residuals (CCR), often called coal ash, are the waste left over after utilities burn coal to generate electricity.
Although the EPA rule designates coal ash as nonhazardous waste, the federal agency implemented the regulations because coal contains contaminants like mercury, cadmium and arsenic associated with cancer and various other serious health effects.
Coal ash is disposed of in wet form in large surface impoundments and in dry form in landfills. Stored without proper protections, coal ash contaminants can leach into groundwater and potentially migrate to drinking water sources, posing public health concerns, the EPA says.
A May 2017 report to the Indiana Department of Environmental Management noted that levels of contaminants in many of the Vecten monitoring wells were stable or decreasing and it appears the contamination has remained close to the landfill boundary.
Residents near the A.B. Brown power plant are served by Evansville city water through the German Township Water District.
Vectren has recycled its coal ash since 2009, selling it for use in cement. Chase Kelley, vice president of corporate communications, said plans to close the A.B. Brown ash pond are being finalized.
She said the utility hopes that coal ash from the pond can be recovered and recycled in a similar fashion. That process could last as long as 12 years. However, if those plans fall through the ash pond will be closed and the ash will remain in the pond.
Plans to close in place F.B. Culley's coal ash surface impoundment, referred to as its East Ash Pond, are already started.
Retherford said that in April the plan for closing the Culley ash pond will be submitted to IDEM and the process will include a public hearing.
A new pond with a protective lining will be built at the site to store wastewater from the power plant which will be treated before it is discharged.