Santee Cooper on Monday filed plans with state regulators to enclose the coal ash ponds at its closed Grainger electric plant here into a cement-fortified vault designed to prevent contaminants, including arsenic, from seeping into nearby groundwater and the adjacent Waccamaw River, the state-owned utility said in a news release.
The proposal would need approval from the S.C. Department of Health and Environmental Control before it could be implemented.
DHEC spokeswoman Lindsey Evans said the proposal is under review but she “cannot speculate about how long that review will take.” Evans said the public would be given a chance to comment on the proposal before any action is taken.
Santee Cooper said the proposal, if approved, would take about three years to implement and would cost about $40 million – less than half the amount of other disposal methods the utility studied. The Southern Environmental Law Center has called for the utility to remove the ponds from the Grainger property so the slurry can be disposed of off-site. Frank Holleman, a lawyer for the environmental center, could not be reached for comment Monday.
“The vault is effective, permanent and a proven method to close such ponds,” R.M. Singletary, Santee Cooper’s vice president for corporate services, said in a statement. “It will prevent ash from migrating beyond the vault, which also ensures water quality standards, and so it is safe for the environment. Additionally, because the material remains on site, it minimizes community impact by reducing the number of trucks required to complete the closure.”
There are two coal ash ponds on the Grainger property. The ponds include waste byproducts from the coal-burning power plant, which operated from 1966 until it was shut down last year. Santee Cooper’s plan calls for pond No. 2 to be excavated and its contents dumped into pond No. 1.
The plan would then create a barrier wall surrounding pond No. 1 by using the existing Bear Bluff geological formation – a stiff clay wall located 15 feet to 25 feet below the earth’s surface that is estimated to be at least 35 feet thick. The formation would be fortified with cement to isolate the ash and groundwater. The vault would be covered with a synthetic cap, and vegetation would be planted in soil placed atop the cap. The area where pond No. 2 was located would be maintained as wetlands.
“We examined several plans that met environmental objectives and used proven technology and sound engineering, and then chose the plan which met that criteria and was the most cost effective method of closure,” Singletary said in a statement. “I am confident that this closure plan addresses the best interests of those living in the community near Grainger, our customers and the state as a whole.”
The coal ash ponds have been a point of contention for environmentalists, sparking a pair of pending lawsuits filed against Santee Cooper by the Southern Environmental Law Center.
Environmental tests show pollution is seeping into groundwater from the unlined ponds, which total about 82 acres or more than three times the size of the lake at Broadway at the Beach. The ponds currently are separated from the Waccamaw River by earthen berms that sometimes are submerged when the river’s water levels are high.
High levels of arsenic and other contaminants have been migrating since at least the 1990s from the ponds into surrounding groundwater. Environmentalists say the pollution threatens the river, fish and possibly drinking water but Santee Cooper spokeswoman Mollie Gore has said all pollution is confined on the Grainger site.
Contact DAVID WREN at 626-0281