Warren officials discuss ongoing sewer, drain improvements

By: Brian Louwers | Warren Weekly | Published February 23, 2018

 Warren City Council member Kelly Colegio recently asked about the city’s ongoing efforts to comply with a federal National Pollutant Discharge Elimination System permit that will require Warren to eliminate sanitary sewer overflows and “flow blending” measures during extremely wet weather by October 2021.

Warren City Council member Kelly Colegio recently asked about the city’s ongoing efforts to comply with a federal National Pollutant Discharge Elimination System permit that will require Warren to eliminate sanitary sewer overflows and “flow blending” measures during extremely wet weather by October 2021.

Photo by Brian Louwers

WARREN  — Whether they’re E. coli “hot spots” or ongoing “areas of concern” in the storm drain system, what’s being done to address them and the potential for basement flooding were on the agenda for two separate Warren meetings this month.

At the request of City Council member Kelly Colegio, the council and department administrators charged with managing the city’s sewer, drain and wastewater treatment infrastructure discussed ongoing efforts to comply with state and federal guidelines during a committee of the whole session Feb. 12. The topic came back up on the agenda for the City Council’s regular meeting Feb. 13.

During the council’s committee meeting, Colegio asked Warren Waste Water Treatment Plant Division Head David Monette and City Engineer James VanHavermaat to address a list of hot spots where testing showed that bacterial contamination, including E.coli, could be entering the storm sewer system, possibly through an illicit sanitary sewer connection. The issue surfaced in December, when Macomb County Public Works Commissioner Candice Miller announced the discovery of high levels of bacteria at two locations. Miller later announced that “a significant source” of E. coli bacteria had been located and “eliminated” in Warren.

In January, VanHavermaat told council members that the source was a property in the city of Warren, but that the bacteria, in fact, had entered the storm drain system through a county sewer. Both city and county officials said work would continue to pinpoint illicit or legacy connections that could potentially result in bacterial contamination of open drains, including the Red Run Drain, and potentially the Clinton River and Lake St. Clair.

On Feb. 12, VanHavermaat said 24 “areas of concern,” previously identified by city crews, remained unaddressed, but he stressed that not all of them pose a serious issue.

“Hot spots is an inappropriate term. The connotation is that there’s something seriously wrong,” VanHavermaat said. “If you look through this list … there’s only a few of these that are serious, and the other thing is, some of these things on this list are things that have already been corrected, and we’re waiting for a final outcome.

“As a takeaway, there’s only a few of them that are really something that’s a major concern at this time. Everything else we’re either working on or we just have to study further,” VanHavermaat said.

Colegio also questioned the city’s ongoing efforts to comply with a federal National Pollutant Discharge Elimination System permit that will require Warren to eliminate sanitary sewer overflows and “flow blending” measures during extremely wet weather by October 2021.

Sanitary sewer overflows are the release of untreated raw sewage and industrial wastewater that typically occur during wet weather, when flow into the sanitary sewer system exceeds capacity as a result of groundwater intrusion, or more commonly in Warren, because of inflow from storm sewer drains.

Flow blending occurs when the flow of wastewater transported by a sanitary sewer for treatment exceeds the plant’s capacity. In such instances, secondary treatment with biological organisms is skipped for a portion of the contaminated water. The filtered flow is then mixed with fully treated water and is disinfected with chlorine or ultraviolet light prior to discharge.

“It’s not something I think anybody likes the thought of,” Colegio said. “Even if it does meet certain standards, personally, for me, the thought of it — it’s cringeworthy.”

Monette said the Warren Waste Water Treatment Plant was designed to process 36 million gallons of water per day, but it can treat up to 54 million gallons.

“The other portion we do primary treatment, and we blend them together again before we discharge. We disinfect and we discharge, and it still meets all of our limits,” Monette said.

VanHavermaat said the city has taken proactive steps to avoid environmental contamination, as well as basement drain backups, but that the learning process is ongoing for all of the entities responsible for managing stormwater, sewage and wastewater treatment.

“We’ve spent $20 million on relief sewers already. We’ve gone through all kinds of changes to achieve a result,” VanHavermaat said. “It’s not like we’re sitting on our hands and saying, ‘Let’s have basement flooding.’ We want to correct these problems.”

He added that while eliminating flow blending was part of the city’s agreement for the reissued NPDES permit, the practice was actually recommended by engineers at the Environmental Protection Agency. Officials said flow blending has always occurred at the Warren plant, but at some point, a decision was made by the oversight agencies that no form of physical treatment is equivalent to treatment by biological microorganisms.

Colegio asked about a letter sent from the mayor’s office to federal officials in November 2015, while the U.S. Senate was considering changes that would have resulted in costly requirements for Warren and other municipalities responsible for managing sewer infrastructure. The council had been presented with a range of options as far back as 2013, including a plan to eliminate storm drain tie-ins, and at the time, was taking steps to facilitate a connection with the Oakland Macomb Interceptor Drain. But the options included in the letter went beyond those presented to the council previously by the city’s engineering team.

Ultimately, Warren could not come to equitable terms for an OMID connection and opted instead to pursue a heavy flow management system of relief sewers, improvements to the Nine Mile Road pump station and the construction of an 18 million-gallon detention basin in the southeast corner of the city.

The total cost for the improvements is roughly $53 million. Construction of the detention basin, designed to increase capacity of the sewer system, is expected to begin in 2019.

Colegio asked, “But we are coming into compliance by 2021, and we will no longer be flow blending and we will no longer have SSOs, correct? If we build the basin?”

“That’s the plan,” Monette said.