BALTIMORE (WJZ) — The Baltimore City Department of Public Works on Friday defended its handling of a wastewater treatment plant that has been seized by the state after regulators and watchdogs claimed the facility discharged raw sewage into the Back River, saying a sample recently collected near the facility was not solid waste.

A sample collected by the Maryland Department of the Environment near the Back River Wastewater Treatment Plant contained no living organisms, “indicating there were no undigested byproducts,” the city agency said.

READ MORE: Two Teenagers Shot, One Killed, At Inner Harbor During Memorial Day Weekend, Police Say

DPW said the sample appeared to be similar to one collected on March 23 by the advocacy group Blue Water Baltimore. Both gave off a strong odor, which DPW likened to marsh mud.

The agency claims the “continuous characterization of discharges from the Back River Wastewater Treatment Plant as untreated wastewater is absolutely not factual.”

In March, Maryland Environment Secretary Ben Grumbles directed the Maryland Environmental Service to take over operations of the facility in response to pollution and other compliance issues at the plant, the largest of its kind in the state.

During an inspection of the facility earlier in the month, state officials found only two of the facility’s 11 primary settling tanks were in service, and only one of those was operating correctly, according to a March 27 directive from the Maryland Department of the Environment.

“Additional data from Discharge Monitoring Reports submitted by Baltimore City indicate monthly violations of total suspended solids, total nitrogen, and total phosphorus,” the directive said.

READ MORE: Jarrettsville Young Marines Honor Fallen Heroes, Prepare For Memorial Day

Grumbles tasked the Maryland Environmental Service with ensuring the city complies with the requirements of the facility’s discharge permit and halts all “illegal discharges.”

DPW has maintained that claims the plant is discharging untreated sewage into the water are false.

Blue Water Baltimore on Wednesday said it is proceeding with a federal lawsuit against the city after failing to reach a settlement agreement. The group filed the case last December, claiming the city has violated the federal Clean Water Act at both the Patapsco and Back River Wastewater Treatment Plants.

“The time for finger-pointing is over. We can’t wait any longer, and proceeding with our federal enforcement action is necessary at this point,” said Alice Volpitta, Baltimore Harbor Waterkeeper at Blue Water Baltimore. “The latest reports show that the pollution is getting worse and jeopardizing worker safety, and after four months of negotiation we still don’t have the information necessary to develop a settlement agreement. We’re moving forward with our case because the City must be held accountable to the public for a transparent solution.”

Last August, after detecting “unusually high fecal bacteria levels” near the Patapsco plant, the group alleged there “have been daily illegal discharges of millions of gallons of partially untreated sewage” from both plants for more than a year.

Both facilities, which are owned and run by Baltimore City, have previously come under fire from the state for unauthorized discharges of pollutants, which the state says undermine efforts to restore the Chesapeake Bay and other natural resources.

MORE NEWS: Baltimore City And Surrounding Communities Experiencing High Community Transmission Of COVID-19

In January, Maryland Attorney General Brian Frosh sued the city on behalf of MDE in response to “repeated violations” found during multiple inspections.

CBS Baltimore Staff