Lake Norman water quality update - April 9, 2018

Published Monday, April 9, 2018 2:12 am
by [email protected] (Bill Russell)

dukeLake Norman water quality update

The following statement was issued by Duke Energy to members of the Lake Norman Chamber f Commerce and concerned citizens on April 9, 2019.  For more information visit: [email protected]   

Key points 

Drinking water supplies near Lake Norman and lake water quality remain safe. Nothing has changed for those who live, work and play near Lake Norman.

The purpose of testing groundwater near ash basins is to determine which ash basins utilities should close around the nation. Duke Energy has already committed to closing all our ash basins, and work is well under way to close basins in ways that protect communities and the environment.

We continue to follow state law and federal requirements that govern coal ash management.

Background
Duke Energy has done extensive groundwater monitoring for the North Carolina coal ash law, and the testing described in recent news stories is a separate effort required under the federal coal ash rule (Coal Combustion Residuals or CCR rule).

When you combine the data we have from both state and federal programs, we have an enormous amount of information on groundwater around our coal ash basins. All of these data are factored into how we plan to safely close ash basins and what additional measures are needed to protect groundwater in the process.

What?s new?
The recent federal coal ash rule lays out a prescriptive process for monitoring groundwater. This involves first reporting baseline data, and then taking additional samples and analyzing data to determine next steps. Duke Energy completed annual groundwater monitoring reports for each of our sites and posted them to our CCR compliance website on Feb. 6. These reports transparently contain our raw, baseline data from the groundwater monitoring wells, as required by the federal rule.

The groundwater monitoring wells for the federal CCR rule are located immediately next to the basin or landfill and do not reflect groundwater conditions farther away or off plant property where neighbors are located. We continue to see no concerns for nearby drinking water wells or lake water quality.

It?s important to remember that the trace elements you find in coal and coal ash also occur naturally in rocks and soils. Our next step in this process is to determine how much is naturally occurring at each plant site and if ash basins contribute additional elements. We expect that work to conclude in late summer.

Keep in mind that the amounts of substances in groundwater are generally very small. Most elements are measured in parts per billion, which is equivalent to one second in 32 years or one penny in $10 million.

Bottom line 

The primary purpose of the federal groundwater monitoring program is to inform whether a utility needs to close ash basins; however, Duke Energy has already committed to doing that and is well down the path of closing basins and preparing to close others.

While all this additional groundwater data is useful to gather, we are not waiting for this analysis to plan for basin closures. We have already committed to closing ash basins in ways that protect the environment and communities. We have closure activities underway at many sites or projects in process to prepare for the closure process.

Radium
The U.S. Geologic Survey notes: "?Radioactive elements in coal and fly ash should not be sources of alarm. The vast majority of coal and the majority of fly ash are not significantly enriched in radioactive elements, or in associated radioactivity, compared to common soils or rocks."
In the Carolinas, geology often includes granite and other rock formations that include uranium, and uranium degrades as radium.

At Marshall Steam Station, for example, of the 350 samples we?ve taken on plant property for the federal rule so far, about 30 groundwater samples showed elevated radium levels.

We do not detect elevated radium in ash pore water or in many shallow wells. This may mean site geochemistry is more of a driver than the ash itself. Routine sampling of permitted outfalls for permit renewals shows no elevated radium levels. This demonstrates nearby lakes are well protected.

Additional resources
Public water supplies monitor for radium and many other parameters in their treated drinking water. Those with questions related to their public drinking water or community well quality may wish to contact their water supplier for more details.

Duke Energy reports its data to state regulators at the N.C. Department of Environmental Quality. Those with questions related to Marshall Steam Station may wish to contact the NCDEQ Mooresville Regional Office for details on coal ash and water quality.

USGS fact sheet FS-163-97, Radioactive Elements in Coal and Fly Ash: https://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.html

N.C. Division of Water Resources, Susceptibility to elevated radon in groundwater map: https://files.nc.gov/ncdeq/Energy%20Mineral%20and%20Land%20Resources/Geological%2 0Survey/Photos_Images_Geologic/geology_matters/Radon%20in%20Groundwater%20in% 20NC%20-%20Draft%20map.pdf

N.C. Department of Health and Human Services, Radiation Protection Section, Radon map in NC: http://www.ncradon.org/ncradon/#

Duke University, Naturally occurring contaminants in North Carolina: https://dukewater.cee.duke.edu/Radium