Arsenic at Robinson Plant ash basin raises alarms

By Samantha Lyles, Staff Writer,

As Duke Energy continues planning the closure of its coal ash basin at the H.B. Robinson Plant north of Hartsville, regulators from South Carolina Department of Health and Environmental Control (SC DHEC) and attorneys with the Southern Environmental Law Center (SELC), a non-profit based in Chapel Hill, are calling for Duke to clean up dangerous levels of arsenic in the ash pond.

Utilities with coal-fired power plants often store waste coal ash in pits on-site, and the pits are normally lined with layers of clay to prevent toxins from penetrating into groundwater, but the ash pond at the Robinson Plant is unlined. A Feb. 24, 2015 letter from SC DHEC the says that ash has penetrated 18 feet below the water table, and groundwater samples show unsafe levels of arsenic.

Arsenic is a naturally occurring element present in rocks and soil, air and water, but it is poisonous and a known carcinogen capable of destroying the liver and kidneys, damaging the heart, and decimating red and white blood cell counts. Arsenic is a by-product of coal ash, which is produced in mass quantities by coal-fired power plants, like the old Unit 1 plant at Robinson.

The waste ash from Unit 1 was first deposited in the 1960 fill area, a 25-acre disposal site located west of the coal plant. Subsequent deposits were placed in a dedicated ash basin, a 72-acre area with wet and dry disposal sites, constructed in the mid 1970s by damming an unnamed tributary to Black Creek. The basin received sluiced ash – mixed with water for wet disposal – until Unit 1 was decommissioned in October of 2012.

There is no direct outfall from the ash basin to nearby Lake Robinson, the man-made lake formed by impounding Black Creek when the plant was built in 1959, but there is an outfall to the basin’s discharge canal, permitted as a re-route for storm water. Though the ash basin’s surface is dry, the ash deposit runs deep. According to Duke’s Dec. 2014 report on basin closure options, within the thalweg (the deepest portion of the channel in the basin center) the coal ash is 53 feet thick.

Among environmental advocates, there is concern that deposits of arsenic in that coal ash poses a danger to groundwater and waterways.

“They put millions of tons of waste containing heavy metals and toxins in earthen unlined pits often next to rivers and lakes, held back only by dikes made of earth, almost all of which we have come across, leak,” says Frank Holleman, senior litigator with the SELC.

According to the Environmental Protection Agency, similar dumping sites located adjacent to waterways are the number one pollution source for rivers and lakes. Holleman says the problem is even worse in South Carolina, since every major river system in our state has at least one set of these coal ash lagoons located nearby.

Holleman says the SELC is concerned about the Robinson ash basin for a few reasons, first of which is the high quantity of arsenic present in test samples. On a few occasions spaced out over several months, SC DHEC tested over 30 well sites at the ash pit. The most recent tests, conducted in December of 2014, revealed alarmingly high levels of arsenic in some locations.

The safe standard for arsenic content in drinkable water is no more than 10 parts per billion (or micrograms per liter), but one test site (MW-109S) returned a count of 1,100. This well is listed in Duke’s closure report as being 45 feet deep, with water found 37.78 feet down.

In response, Duke media relations rep Erin Culbert wrote in an email to the News and Press: “SELC stated in a Feb. 2 letter to DHEC that arsenic levels in groundwater exceed 1,000 parts per billion. The monitoring well they reference is actually located inside the ash basin itself and does not represent groundwater conditions outside the basin.”

Culbert also notes that groundwater is not flowing toward plant neighbors, and there are no private groundwater wells located between the ash basin and Lake Robinson, and adds:

“We have been monitoring water quality in Lake Robinson since the 1970s. Lake water quality is good, with no concern for arsenic. (Water quality sampling consistently shows arsenic levels are less than or near the laboratory detection limit of 0.5 parts per billion.)”

Still, several other test sites also showed high arsenic content, and SC DHEC has ordered Duke to test and evaluate the presence of arsenic in groundwater at the site and formulate a work plan to remedy the problem.

Holleman says that in 2012, SELC – on behalf of citizens and communities – sued the SCE & G Wateree Plant in Columbia and Santee Cooper’s Grainger Plant in Conway to force compliance with state arsenic pollution standards. Those cases were settled and the utilities agreed to clean up their ash basins and move the waste to safe, dry-lined storage.

By the end of 2013, further enforcement suits were pending regarding all 14 of Duke’s coal ash disposal sites in North Carolina. The Feb. 2, 2014 spill at Duke’s Eden, North Carolina ash basin threw the danger into sharp relief when a leaky levee released as much as 82,000 tons of coal ash and 27 million gallons of water contaminated with metals and chemicals into the Dan River.

Catawba Riverkeeper Foundation, which partnered with SELC to sue Duke, summed up the danger with this statement on its website:

“This is a prime example for why, even if a power plant is no longer burning coal and generating waste, the waste left behind from decades of operation with primitive storage needs to be cleaned up and taken off the banks of drinking water sources.”

A month after the Dan River spill, a federal criminal grand jury was convened in North Carolina to examine Duke’s coal ash storage practices. Holleman says this helped amp up the pressure on Duke to get moving on ash basin cleanup and safety.

SELC and DHEC then looked into problems at Duke’s Saluda River coal ash storage and found numerous problems, which Duke has since has committed to clean up. Holleman says Duke has also committed to clean up four more sites in North Carolina, and ten other sites are under review.

“What that meant when we reached that agreement with Duke was that utilities have agreed to clean up every single coal ash site they have in South Carolina – except Robinson. It’s the only one left,” says Holleman.

Culbert says the company is in the process of evaluating what it would take to safely clean up and close the ash basin, and testing of groundwater will continue through August of 2015, with a closure plan due for submission to SC DHEC by November. Culbert outlined the main closure options in an email:

“There are several options for closing ash basins. We believe that site- specific engineering should help inform the methods used and may include a combination of:

• Excavating and relocating ash to a fully lined structural fill

• Excavating and relocating the ash to a lined landfill (on-site or off-site)

• Capping the ash with an engineered synthetic barrier system, either in place or after being consolidated to a smaller area on-site

Schedules for closing basins depend significantly on a variety of factors, including state requirements, the amount of ash at the site, whether plant system conversions are needed and whether new storage facilities will need to be designed, permitted and constructed.”

When asked about the closure options, Darlington County Council chairman Bobby Hudson expressed confidence that Duke would act in the best interest of the community.

“Their safety record up there speaks for itself. If the citizens up there are concerned, they haven’t expressed it to me or to council. The prior (owner) CP&L was a good corporate citizen, and Duke, I hope, will do the right thing. I’m sure they will. It’s just going to take a matter of time,” said Hudson.

Holleman says another wrinkle in the closure plans is the ash basin’s history as a disposal site for low-level radioactive waste, mostly sediment and chemically treated wastewater from cleaning fossil-fueled boilers. Some of this waste was not suited for disposal at the Barnwell Low-Level Radioactive Waste site, and the company did not pursue a costlier option of shipping the waste to an acceptable site in the state of Washington. Instead CP&L opted to deposit the waste in their own ash pond.

In July of 1980, CP&L transferred 3,000 cubic meters of slightly contaminated radioactive waste sediment into the ash pond without permission from SC DHEC or the Nuclear Regulatory Commission (NRC). The plant was cited for the violation.

On several other occasions, waste containing legally permissible levels of Cobalt-60 was disposed of in the ash pond. CP&L obtained license from NRC for these disposals, which took place between 1983 and 1998.

Duke Energy spokesperson Erin Culbert said the practice was “acceptable” in the industry during that time, and the company is monitoring the ash basin to track the presence of Cobalt-60.

“There is no impact to the public from this material. In 2014, as part of the ash basin closure planning, about 40 soil samples were collected throughout the ash basin, and each sample showed less than detectable results for Cobalt-60,” Culbert wrote to the News and Press.

She added that weekly collections of surface water, quarterly samples from groundwater monitoring wells, and semiannual shoreline sediment collections are “non-detectable” for Cobalt-60.

Holleman also expressed concerns about a flood evaluation report Duke submitted to SC DHEC in September of 2014, a report showing the storm drainage infrastructure for the ash pond site as inadequate to handle a 50-year flood.

Culbert responded that the storm water study in question was based on bad modeling and Duke has since given SC DHEC a corrected report with updated information. She wrote that there would be “no impact to the ash basin from a 50-year storm event.”

Holleman points out that utilities, while trusted to serve the public, can sometimes engage in unscrupulous practices to maximize profits, and it is crucial that the public retain the right to sue for fair treatment. However, that right to sue may be under attack in the South Carolina Legislature, as Holleman says the Senate will debate a bill this session that could strip away the public’s right to sue a utility, leaving enforcement of environmental issues entirely up to an understaffed and underfunded SC DHEC. He suggests writing and calling your elected representatives to let them know your feelings on this matter before it’s too late.

Author: Duane Childers

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