The Holts Summit Board of Aldermen last week approved allowing the mayor to sign an abatement order on consent from the Missouri Department of Natural Resources — paying about $2,000 to DNR for expenses it accrued during a January 2017 investigation into pollution of Rivaux Creek by the city's sewer system.
A sewer main near Holts Summit's sewer treatment facility had been plugged early last year, causing an overflow which affected a tributary to Rivaux Creek, according to the abatement order. Holts Summit staff removed the plug several days after they estimate it started.
The investigation by DNR after the incident found the ammonia as nitrogen concentration, a measure for the amount of ammonia nitrogen in water, was 2.6 mg/L above quality criteria and observed fine sludge deposits.
City Administrator Rick Hess said the plug likely was caused by somebody dumping grease down a manhole, but Holts Summit is still on the hook for the money because it is part of the city's system.
"Hopefully, if there is a next time, we'll catch them," Hess said, adding that if the city does catch someone dumping, it can result in expensive fines.
There were other instances of ammonia as nitrogen levels going above quality criteria in Rivaux Creek and Turkey Creek in 2016 and early 2017, according to the abatement order. Hess said Holts Summit's efforts to make the Choctaw Ridge Lagoon inactive and start a project to upgrade the sewer system to take the treatment facility offline should solve any issues not caused by dumping.
Hess said it was odd to receive the abatement order for consent over a year after the investigation was completed, but the city's best option was to accept it.
"We're just kind of out of luck on that one — cheaper to pay it then fight it," Hess said.