Jul 23, 2023

Concerns over exposed sludge in New Minas, heat could worsen sewage stench

County of Kings aims to have regional plant rehabilitated by end of year


NEW MINAS, N.S. — New Minas residents concerned over ongoing odour from the regional sewage treatment plant will believe the problem is fixed when they can no longer smell it.

Esther Bradley, a New Minas resident and owner of Archie's Welding at the end of Jones Road near the sewage treatment plant, said on May 25 that all she wants is for the problem to be fixed. She said the stench is still bad, although it hadn't been as consistent as in prior weeks.

"It comes and goes, but it doesn't seem to be lasting as long," Bradley said.

Sometimes when she goes to work in the morning, she notices the smell is very bad. Then the wind changes direction and there is temporary relief. Bradley said wind and weather conditions probably have a lot to do with the intensity of the stench, and where people are experiencing it.

New Minas, N.S., area residents express anger, frustration with ongoing sewage odour

Addressing the odour: Work ongoing at New Minas, N.S., regional sewage plant

Because there are no tall trees or buildings between the sewage plant and their welding shop, Bradley said the smell easily carries directly to them. This is particularly the case when the wind is blowing out of the north.

With warmer temperatures arriving and the ongoing desludging work, Bradley said she is concerned the smell could get worse. Depending on the prevailing wind, having this material exposed to the air could make the odour in the area unbearable.

Bradley said New Minas accounts for about 21 per cent of the material entering the regional sewer, meaning the remaining 79 per cent comes from neighbouring communities and industrial food processing. She said it's unacceptable that New Minas must tolerate and endure the stench when other areas have a greater responsibility for creating it.

Bradley said inorganics in sewer systems are not a problem specific to the New Minas plant and she wonders why grinders and filters weren't acting to keep these materials, including face masks and so-called disposable or flushable wipes, out of the lagoons and off the aerators.

Bradley contends that a new regional sewage treatment plant should be built to take some of the pressure off the aging New Minas facility. She suggested it be built in Coldbrook close to the County of Kings administrative building and public works garage so it can be closely monitored.

Bradley said her father, William John Lockhart, is recognized as one of the founding fathers of the Village of New Minas. He used to own the land where the treatment plant is located. She said he would be troubled by the current situation.

Although she finds the smell intolerable, Bradley said she is appreciative of engineering and public works operations manager Aaron Dondale's willingness to answer questions and share information.

The County of Kings, the owner and operator of the plant, continues working to correct the problem. Dondale said on May 31 that, first and foremost, it apologizes for the odour.

He said rectifying the situation involves two critical processes, desludging the lagoons and installing new aeration equipment.

"Removing sludge and improving airflow are the two most important things we can do to reduce the severity of foul odours coming from the plant," Dondale said.

The municipality has hired firms with barges equipped with suction pumps to remove sludge from the lagoons, and this process is ongoing. This work involves the temporary lowering and filling of the lagoons and has unfortunately triggered odour problems.

Dondale said wastewater lagoons use a biological process to treat wastewater. Adding oxygen to the water is an essential component in the process. He said this plant and system features large blower machinery that transfers air through headers to diffusers located in the lagoons.

The first two of five lagoons contain more than 800 diffusers, each one about three feet in diameter and five feet high. These are anchored to the floor of the lagoons with cement pads.

The municipality has purchased new header piping and diffusers and completed the contracting process to select a company for installation. Dondale said the new header pipes have been installed. The new diffusers can be installed after the sludge has been removed.

Dondale said the municipality and its partners endeavour to have the work completed by the end of the calendar year. They believe the combination of sludge removal and installation of new aeration infrastructure "will dramatically improve operations."

However, he said, as is the case with any major renovation work, they may encounter unexpected changes to their work scope and schedule.

"We know how important this work is to our communities and we are working very hard to keep these important upgrades and restoration efforts on track," Dondale said.

Concerned resident Tony Wells, who has 36 years of experience in wastewater treatment, said he doesn't know how the municipality got away with the situation at the plant for so long.

He heard at a recent public meeting that new aeration equipment is expected to be installed by November. Wells said he hopes this is the case, but he has a hard time believing it. The municipality could run into supply chain issues and the arrival of the equipment could be delayed.

He said it's been his experience that two identical pieces of equipment coming off the same assembly line can have different operational nuances or mechanical traits, so there may be some bugs that need to be worked out.

Wells said he doesn't understand how an operator didn't catch on to the problems sooner. Properly working aerators draw air into the water to provide oxygen. They cause a lot of churning and bubbling in the surrounding wastewater.

For example, the first lagoon has 522 aerators. Wells said these should have been generating a lot of movement. If this wasn't readily visible, it should have been apparent there was a problem.

"The best thing they can do in my opinion, as I mentioned at the (May 11) meeting, is get some misting going to keep the wolves at bay as it were because without it, it's still going to stink," Wells said.

He said misting or perfuming is a relatively inexpensive measure to address the smell and "it would certainly get the neighbours off your back."

The rotten egg smell being generated by the regional sewage treatment plant in New Minas is hydrogen sulphide (H2S) gas, concerned resident Tony Wells emphasized.

In high enough concentrations, it is toxic and potentially fatal.

In recent email correspondence, concerned New Minas resident Donald Teed asked why the odour is being treated as an inconvenience and not a health issue. He said he lives in the Milne Subdivision and some days must keep his windows closed.

He said there is an ongoing saga of municipal leaders claiming the problem is fixed, only to have it resurface the following year. Considering that ongoing residential development within the plant's service area would increase the amount of sewage going to the facility, he's considering moving.

Several area residents at the May 11 meeting complained about the H2S odour having an impact on their health, including headaches, and itching or burning eyes and throats.

Engineering and public works operations manager Aaron Dondale assured residents the off-gassing H2S is not in high enough concentration to pose a public health risk. He said that for workers to operate at the plant in its current condition, they must always wear gas detection monitors.

"A lot of the smells are very unpleasant, they’re not fun to work in all day long, but we’re not reaching any levels that are causing any health risks to the people working on-site," Dondale said.

Mayor Peter Muttart reiterated the gas isn't posing a health hazard, noting that if gas monitoring equipment had given any such indication, workers wouldn't be allowed in the vicinity of the plant.

In Nova Scotia, air quality is regulated under the Environment Act. For H2S, the maximum permissible ground level concentration is 3 parts per hundred million (pphm) for an averaging period of one hour. For 24 hours, it's 0.6 pphm.

A Facebook page called New Minas and Kentville SMELL has been established by concerned resident Dawn Noakes. This is a forum for members of the public to share information and concerns about the situation at the regional sewage treatment plant.