Port Huron's smelliest conundrum nearing its end

There could be a light at the end of the tunnel in finding a permanent fix to the occasional but strong smell plaguing residents downwind of Port Huron’s wastewater treatment plant downtown.

During a meeting on Monday, City Council members OK’d a new engineering agreement with the firm Fishbeck, Inc., for an odor control study at the facility — weeks after City Manager James Freed first previewed the need for a new system that’d cost in the millions after another installed a couple of years ago reportedly failed.

Although part of council’s consent agenda and not discussed, officials also accepted two settlement agreements, helping the city regain costs from the roughly $2.2 million overhaul of odor control first approved in 2020.

On Monday night, Freed said he anticipated designing and building a new system with Fishbeck’s help would be a two- to three-year project.

“It’ll most likely require carbon filters,” he told council members. “As you recall, we put in an odor control system; it started about three years ago, completed about a year and a half ago. That system clearly has failed. I don’t think anyone would question that the odor control system failed. We’ve been able to recoup more than $1.9 million of refunds back to the city for that system that did not operate as designed. We will take those funds and put them toward a new system that will work.”

Officials have been mum about the odor control issue over the past few weeks amid settlement agreements with the firms Tetra Tech of Michigan, which received the 2020 overhaul bid, as well as and Weiss Construction, which helped install the system put in place in 2021.

According to those agreements, Tetra Tech has to pay costs of $1.8 million within 45 days. There was no settlement payment listed with Weiss, though its account and contract with the city would be formally closed out. Freed later clarifid the difference between Tetra Tech's settlement and the $1.9 million he told to council covered more than $100,000 the city wouldn't have to pay on contract to Weiss.

Representatives of those firms couldn't be immediately reached earlier this week.

Answering concerns about the wastewater smell during an April 8 meeting, Freed had said they were finalizing talks with Fishbeck for a contract that’d help lead to designing a new system estimated anywhere from $5 million to $8 million. No ballpark costs have otherwise been mentioned.

He only briefly elaborated on the coming settlement earlier this month.

“We are appreciative of all parties reaching this mutual agreement, which makes the city whole,” Freed wrote. “Tetra Tech and Wiess are both great firms that do wonderful work. We have always had a great relationship with them and look forward to future work together. They realized there was a problem and stepped up to make it right. I think that speaks volumes about the quality of the firms and how professional and reputable they are. These things happen, but more telling is how they are handled. The document speaks for itself. Our focus now is a rapid plan to correct the odor issue, which we have now engaged a national firm with experience to make this happen.”

How does the odor control system work? What hasn't worked?

Odors from the wastewater treatment plant in the past weren’t immediately identifiable outside the facility near the corner of Quay and Merchant streets last Saturday — the first day of the seasonal farmers market newly operated by the city from a nearby parking lot.

Nor did it appear evident two days later ahead of a tour with city public works staff and the Times Herald at the facility.

That’s because, officials said, they’ve taken steps to curb the issue over the last year or two.

Currently, one system collects odors from multiple locations on site of the facility and “scrubs” them during the treatment process. That system is roughly 20 years old and at the end of its normal lifespan, officials said.

“When we implemented this last project, we took these tanks off that system and kept the old functioning for the remaining part of the plants,” Public Works Director Eric Witter said Monday. “We’re basically starting over. But the previous (plan) was a multiphase odor control project with different treatment technologies potentially at different locations instead of one concentrated area.”

But officials said the technology was put in wrong place or application, and Witter said they couldn’t treat the levels of ammonia present in the plant’s biosolids tanks. Dianna Seifert, the wastewater plant’s superintendent, said that tech can work in the right place where “the solids aren’t as concentrated.”

So, until they identify a new system, working with Fishbeck, officials said they’re stuck with the current system and the small corrections they’ve made along the way to maintain it.

The wastewater treatment plant itself consists of several buildings and levels — both above and below ground.

And it has “two scrubbers” that remove odors, each 7,000 gallons at their fullest, along with use use of chemicals sodium hydroxide and hypochlorite.

During the tour early Monday, Seifert held a couple of small filtration “media” materials used inside the scrubbers — each differing in size and shape but smaller than her hand.

“They have media inside and chemicals washed down over the media, and as they’re doing that, they’re capturing odors,” she said from inside the scrubber room. “It’s in rough shape. Apparently, the west (scrubber) is not operable. We need to get some new equipment for it. A new fan and a new motor. This is the east one. This one is operable. However, it does need some curb work on the roof. So, it’s the curb that supports the fan.”

Seifert said the hydroxide helps the bleach in the hypochlorite from becoming gas, adding, “That’s what the hydroxide does, it keeps it in suspension, so that the hypochlorite, the bleach, can scrub the odors out of the air.”

Atop the scrubber rooms are giant exhaust fans — all in sight of the large tubes that centrally pull air toward sterilizing the odors.

Down a semi-enclosed outdoor corridor of the plant, is the area where trucks pull in to haul solid sludge out of the plant. Whether or not the odor control system is working, that’s a normal place some odors escape the plant. Amanda Huddas, the city’s water and wastewater manager, called it “fugitive odor.”

Now, that it’s near summertime, Seifert said, “If we’re having a good hauling day, it can be up to 15 minutes every hour. Because a truck will come every hour to fill.”

They try to make the most of the time when the weather is good, allowing hauling at times six days a week, including Saturdays, and as Seifert said, on Sundays “in a pinch.”  

“Because it’s critical to get the tanks empty by fall so we have good storage for the winter,” Witter said.

Later on Monday, Freed credited DPW staff with remediation efforts that kept odor control up, tightening up operations with fewer exposed spaces, and that the smell was “significantly better in the downtown.” He said they were “innovative” in addressing a problem “we didn’t see coming.”

The city manager also encouraged those with questions to reach out to public works, citing briefings with the public last summer.

“We took a tour of 30 or 40 residents through the wastewater plant last summer,” Freed said. “We did signups. And folks were just blown away at the size and scope of what goes on over there.”

The city’s public works department can be reached weekdays at (810) 984-9730.

Contact Jackie Smith at (810) 989-6270 or jssmith@gannett.com.