The city is building an island but this is not an island you’d want to vacation on.
At the Committee of the Whole meeting on July 21, Peter Gigliotti of Urban Systems gave a presentation on the city’s wastewater treatment plant.
Among other issues, he mentioned that a growing “island” of sludge is building in the sewage treatment plant and could end up impairing the running of the plant down the road.
Gigliotti said the mechanical plant was added in 1998 and is what is called an extended duration plant. Even though most of the waste sludge is returned back in the process, there is some left, he said.
“Over the years, that sludge has been dumped into cell #2 of the plant,” he said to council. “The result is that it has accumulated to the point where it has formed an ‘island’ of sludge in the pond.”
Gigliotti said that one of the questions that have come up is what to do with the sludge and get the plant operating the way it should be, and in the long-term what to do with the sludge that daily comes off the plant.
Gigliotti said one of the solutions is to remove the sludge, dewater it and haul it away to a ground site (application).
Sasha Bird, manager of development and engineering for the city, told the Gazette in an interview that sludge is a common issue with wastewater lagoons.
“All municipalities that use the lagoon system have to address (the sludge build-up) at some point,” she said.
Other options for the sludge island are geo tubes (a specially engineered textile designed for containment and dewatering of high moisture content sludge and sentiment) or disposal or removal to another location, although that would be quite costly, said Bird.
She adds that as long as the sludge is appropriately managed it poses no threat to the environment.
At the Committee of the Whole meeting, Doug Allin, city administrative officer, said the city would like to see much more collaboration and public consultation before making any decisions on the excess sludge.
“Really, we’re just in the infancy of looking at this issue,” he said.
Mayor Brian Taylor said that the presentation from Urban Systems was very thorough and well done.
Taylor said it doesn’t appear to be an emergency situation. “It all still works, it just could work better,” he said. “In the long run we have to do something about this. We have to plan some strategy about addressing it. The time frames given were fairly (long) 5-10 years.”
He said the problem hasn’t just developed “overnight” and that it will take a while to come up with a solution.
Taylor said there are many different options to deal with the sludge but it can also be an asset.
“Municipalities have used it to fertilize community forests or on farmlands to improve the potency of the soil,” he said. “There are lots of nutrients.”
He also cautioned against public perceptions—concerns about it leaching into the water shed and that kind of thing. I think he gave a very balanced look at what we might consider in the future but nothing jumped out as the situation at this point.”