Kim Schofinski, deputy communications director with Tennessee Department of Environment and Conservation, said the agency is working with the Tennessee Wildlife Resources Agency and local officials.
The source of the fish kill is not known at this time.
TWRA spokesman Matthew Cameron said biologists noted several species of dead fish, including creek minnows and trout, in the Watauga River.
“While there are no trout in Brush Creek, there are several species of dead minnows,” he said.
TDEC conducted a preliminary test on the water and detected high levels of chlorine exceeding four parts per million, the maximum amount the gauge will register.
“Investigators traced chlorine back to a storm drain, but have not identified the source at this time,” he said. “Earlier reports were that it was coming from the wastewater treatment facility, but they have traced it to a storm drain above that facility.”
He said TDEC will be handling the rest of the investigation.
The incident occurred in the general vicinity of the Brush Creek Wastewater Treatment Plant, which is located off Riverview Drive in Johnson City.
In a statement issued Wednesday afternoon, the city said personnel with the water and sewer services department reported foaming in Brush Creek, upstream of its confluence with the Watauga River, to the local TDEC office.
“The city worked with the state to assess the extent of the area exhibiting foaming,” the statement said. “The wastewater collection system along this area was visually inspected and determined to be in working order. The Brush Creek Wastewater Treatment Plant was eliminated as a possible source of the foaming.”