State says too early to know if central office site has groundwater contamination
Published 12:00 am Monday, February 4, 2013
SALISBURY — While the proposed site for the Rowan-Salisbury Schools central office has extensive soil contamination, it’s not yet known if groundwater under the site is contaminated as well and would require clean-up, a state official said.
So far, the city has removed seven underground fuel tanks and 3,500 tons of contaminated soil from the site, a “massive amount,” said Dan Graham, a hydrogeologist with the N.C. Department of Environment and Natural Resources, Underground Storage Tank Section.
But groundwater contamination — and any state-mandated cleanup — can be determined only by digging test wells at the site, Graham said.
“You could speculate to high heaven, but until you have analytical results, you just don’t know for sure,” said Graham, who works in Mooresville and serves as the state’s project manager for the proposed central office site.
The Rowan County Board of Commissioners is scheduled to consider the school central office project today at 3 p.m. Commissioners would have to borrow money to construct the building on behalf of the Rowan-Salisbury Board of Education.
The city bought the former service station in the 300 block of South Main Street in 2007. The state had given the site a clean bill of health in 1991, then reaffirmed the letter of no action in 2007 before the city bought the property.s
But when site preparation began last fall for the school central office construction, soil contamination was discovered, as well as the orphan underground tanks.
Graham said he has seen sites with similar soil contamination but no groundwater contamination. On the other hand, some sites that appeared cleaner than the Salisbury location have actually had groundwater contamination that required abatement, he said.
Graham said he will decide whether the city needs to install test wells after he receives a report about the site next month.
Called an initial abatement action report, this document will detail the total amount of soil excavated, amount and type of contaminants and where the contamination was located on the site.
If wells are required and the groundwater turns out to be contaminated, Graham said he would then consider whether anyone is in danger of coming into contact with the water.
Typically, that includes drinking water wells and other “receptors,” such as basements. No one drinks from a private well in downtown Salisbury, Graham said.
If groundwater contamination is present at the site but falls below state levels and the risk of someone coming into contact with it is low, the contamination could be allowed to dissipate naturally, Graham said.
“There could be groundwater contamination that would not need to be abated,” he said. “You can leave certain groundwater contamination at certain levels because there are no receptors that would be impacted.”
However, if contamination exceeds state standards, Graham would assign a risk level for the site and start a cleanup plan.
“At that point, we would determine how to move forward,” he said.
So far, the city has submitted one report to Graham, prepared by the city’s contractor, Griffith Enterprises of Winston-Salem, which is doing the excavation.
“The city is doing exactly what they are supposed to be doing, and they are well within compliance,” Graham said. “They are trying to get this place cleaned up.”
Because the city is not responsible for the contamination, the state will pay for most of the cleanup costs. The city is responsible for a $20,000 deductible.
The next report is due March 12, but Graham said he would give the city an extension if needed.
“With a site of this magnitude and the fact that they didn’t know the tanks were there, and the city is not the responsible party, I would give them more time if they need it,” Graham said.
Contact reporter Emily Ford at 704-797-4264.