Calling a proposed $25.1-million state fine for coal-ash-induced ground- water contamination at a retired coal plant near Wilmington, N.C., "unprecedented" and "improper," Duke Energy on April 9 filed an appeal aimed at dismissing the Dept. of Environment and Natural Resources' proposed penalty. The fine is not related to the 2014 coal-ash spill at the utility's Dan River powerplant near Eden, N.C.

In its appeal, Duke called the levy "an extreme example of [an] improper civil penalty" and alleged that the DENR "acted in violation of North Carolina law" in calculating the historic state fine.

When announcing the fine in March, DENR Secretary Donald van der Vaart said the agency would hold Duke "accountable for past contamination we have found." At the L.V. Sutton plant, it asserted, Duke "allowed a host of coal-ash contaminants to leach into the groundwater … for several years."

The state determined the fine by calculating the number of days that levels of specific pollutants exceeded groundwater quality standards, and then multiplied that amount by a daily penalty. For the pollutant thallium, for instance, the agency multiplied a $5,000-per-day fine by 1,668 days for an $8.34-million total.

Duke's appeal counters that it previously had reported this data to DENR and that, therefore, the agency was "imposing post-hoc fines arising from monitoring information known ... for at least 10 years." Additionally, the utility alleged that the state failed to permit Duke to take corrective action.

If Duke's appeal fails and the state finds groundwater violations at other plant sites, the utility could face other fines related to its coal-ash basins, says DENR.

In February, Duke Energy announced that it had agreed to a proposed $102-million settlement with the U.S. government over the Dan River coal-ash spill. That settlement is now before a federal judge in Raleigh.