The City of Turlock has been fined $6,000 by the State Water Board for discharging too much of a cancer-causing chemical into the San Joaquin River, following an operational issue at the Turlock Wastewater Treatment Plant.

According to Turlock Municipal Services Director Michael Cooke, the City of Turlock very briefly exceeded the allowed amount of dichlorobromomethane in effluent discharged on July 8, 2013.

"Every now and again something does go awry," Cooke said.

The chemical is a byproduct of the city's chlorination process, used to kill coliform bacteria in wastewater. Due to hot weather the bacteria was more prevalent, forcing the usage of more chlorine.

The exceedence was relatively minor – just about 4 parts per billion more than Turlock is permitted to discharge. In total, Turlock released 41.9 parts per billion of the chemical; Turlock is permitted to release 37.2 parts per billion.

Though the chemical is a potential carcinogen to those who drink it in high concentrations for an extended period of time, it is unlikely to have caused any harm. The minuscule amount discharged by Turlock would have been further diluted in the San Joaquin River.

"We don't think there's a risk to downstream users," Cooke said.

The fine is relatively minor, reflecting the violation. Turlock was fined $216,000 in 2008 for violations dating back to 2000.