Partnering for cleaner water

The Madison Board of Aldermen voted unanimously last Thursday to enter into a reimbursement agreement with Duke Energy for the purpose of solving the town’s recent problem with elevated levels of total trihalomethanes (TTHM).

Madison received a notice of violation in Oct. 2011 indicating the town’s water supply tested above the maximum contaminant level for TTHM during the 12-month period from July 2010 to June 2011. Madison’s TTHM for the period was 0.081 milligrams per liter. The federal standard is 0.080 mg/L.

A public notice sent to Madison water users in Nov. 2011 stated the town’s “system experienced a spike of the total trihalomethanes level during September 2010.” The notice also indicated there were higher than normal levels of bromide from sources upstream and that could have created the problem when the water was treated with chlorine.

Davis Montgomery, district manager for Duke Energy Carolinas, and Michael Brissie, engineering manager at Duke Energy’s Dan River Steam Station, attended last Thursday’s board meeting to address the company’s involvement in helping solve Madison’s problem. Duke Energy has also observed higher concentrations of bromide at the ash basin outfall it operates at Belews Creek, and Montgomery said the company wanted to partner with Madison to help resolve the elevated TTHM created by the presence of bromide.

The agreement states Duke Energy will reimburse the town for “certain technical and engineering expenses.” The contract runs from Jan. 1 through June 30 and includes maximum reimbursements of $300,000 for approved expenses relating to recommended system modifications.

Alderman Tom Rogers asked Montgomery if he thought the problem was fixable.

“It’s a first-time type of situation,” Montgomery said. “There’s no off-the-shelf solution to it because no one else has run into it.’

After checking with industry organizations across the nation, Montgomery said no similar problems were identified. He did say higher TTHM levels were beginning to show up in relation to the natural gas exploration process known as fracking.

“So there’s a little indication that this going to become a little more prevalent than it is today,” Montgomery said. “But, the short answer is, there’s no remedy ready to pull of the shelf and put into place now.”

Montgomery said the company had a team of more than 20 people, including Brissie and his team, working on the problem. He said the company was fully committed to working with the town to solve the issue, but was still in the early stages of research.

Adding a technical flavor to the discussion, Brissie said the high levels of TTHM occur with the combination of chlorine, bromide and certain organic contents in water.

“So if you can eliminate any one of those elements, much like getting rid of one of the three sources of fire, the problem will go away,” Brissie said. “Our first attempt here would be to go after the organic content through the carbon filtration system, since that’s the least costly and most proven technology.”

Brissie said his team would assist the town’s staff with testing at the water plant and trying to find ways to improve the filtration system and regulate TTHM levels.

Board members also asked about the feasibility of finding a solution within the six-month length of the agreement and $300,000 maximum reimbursement. Montgomery said town and Duke Energy representatives will meet near the end of June to discuss potential extensions and increases.