An environmental assessment of the joint Chattanooga-Hamilton County firing range on Moccasin Bend indicates that the nearly 40 years of spent bullets at the site may be causing lead-laden surface water to flow into the Tennessee River.
And local and federal officials say they may need to review a recent decision to keep the guns firing on the Bend.
The assessment, paid for by the National Park Service to estimate the cost of cleaning up the site, shows that about 6,147 tons of surface soil across five areas on the range contain more than 400 mg/kg -- the federal Environmental Protection Agency's acceptable lead limit for the site.
No subsurface soil or water is jeopardized by lead, but the report shows lead-contaminated surface water is likely finding its way to the river, either through stormwater drainage ditches or natural routes.
Lead contamination can impair learning and behavioral development in children, and cause nerve and organ damage in adults, according to the U.S. Centers for Disease Control and Prevention.
Chattanooga's drinking water is collected upstream from the Bend, but the Tennessee River serves as a drinking water source for towns to the west of the Scenic City, out to Paducah, Ky.
In a separate note, the assessment found that a fire pit police had used to burn "cardboard targets, ammunition boxes and household trash" contained lead and arsenic, and was potentially leeching naphthalene, selenium and mercury -- all semi-volatile organic compounds -- into the groundwater under the Bend.
The Agency for Toxic Substances and Disease Registry shows high concentrations of naphthalene destroys red blood cells in humans and causes cancer in animals; toxic levels of selenium cause neurological damage; and too much mercury can damage the brain, kidneys and developing fetuses.
The firing range has caused friction between Friends of Moccasin Bend, an advocacy group for the nearby Moccasin Bend National Archaeological District, and the city and county governments.
Former local officials agreed to move the gun range off the Bend and donate the land to the National Park Service more than a decade ago to expand the archaeological district and the Chickamauga and Chattanooga National Military Park.
But in August, current administrations said the $1.2 million price tag to remove the 40 years of lead in the ground at the range -- coupled with the cost of relocating the training facility after a planned indoor range was nixed last year -- was too great.
But Thursday, Hamilton County Mayor Jim Coppinger said the findings in the environmental assessment give "obvious reason to be concerned."
"It's something we take seriously, and I'm comfortable in saying the city takes it seriously," Coppinger said. "Given the report, I think it's important that we go back and review our options with regard to the firing range."
But Coppinger stressed that police still need a viable place to train.
"At the end of the day, what we have to be able to do is to offer our law enforcement personnel, including in the municipalities, the best training we can possibly offer them," Coppinger said.
Chattanooga Mayor Andy Berke was traveling and unavailable for comment Thursday, but spokeswoman Lacie Stone said the administration is "thoroughly reviewing the report" and may do its own water quality analysis on the site.
Stone said the city was dedicated to providing green space and parks for residents, adding that it gave the park service 13 acres on the Bend last year.
"And even though building a new, indoor police training facility is cost prohibitive, we will continue to work with Friends of Moccasin Bend toward a solution that is in the best interest of Chattanooga and our public safety employees," Stone said.
Whether a firing range is there or not, the city and county are responsible for its environmental impacts, according to state law.
Troy Keith, environmental field office manager with the Tennessee Department of Environment and Conservation, said his agency did not regulate the firing range site, because no one has asked for help or complained.
But if toxins are leaking onto the river or groundwater, TDEC would get involved.
"We certainly would not like contamination coming from the site, so if we find that, it would be actionable," Keith said.
Moccasin Bend's archaeological district designation was initially driven by federal officials, and U.S. Rep. Chuck Fleischmann said Thursday he was picking up the torch.
He said he set up a meeting for later this month with the Moccasin Bend group, along with representatives from Sens. Bob Corker's and Lamar Alexander's offices to find a solution.
"I just want to work toward an amicable solution consistent with what's been laid out," Fleischmann said. "It's going to be a beautiful addition to the national park."
Contact staff writer Louie Brogdon at email@example.com, @glbrogdoniv on Twitter or at 423-757-6481.