Sludge will leave as sand comes in as Hinesburg ramps up work on renovating its wastewater treatment facility.
What leaves will not really be sludge, it is basically dirt, said utilities director Erik Bailey.
The sludge being removed from one of three lagoons that make up the town’s wastewater system is being spun by centrifugal force to remove water, and it will then be trucked away to Canada as dirt or compost, he said.
The Hinesburg Selectboard awarded a contract to low bidder Munson Earth Moving of Williston for $1,445,000 for the first phase of upgrading the system, which will stabilize the lagoon subsurface.
Jason Booth, a project engineer from Aldrich + Elliott, was pleased with the competitiveness of the bid process.
“It was good timing and I think there were a number of contractors that were hungry and still needed to fill a bit of their plate,” Booth said.
Hundreds of truck trips will be needed to bring in enough sand to fill a lagoon-sized area, he said.
Town officials were shocked to learn in August 2019 that 60 feet below the lagoon’s surface was a layer of wet clay. Before construction can begin that needs to be altered to make a firm foundation.
It will likely be a year before that massive number of Munson Earth Moving trucks start bringing in sand to the site where the new and improved treatment facility will be constructed.
The total project is expected to cost $11.7 million, Bailey said. The expenditure was approved by voters in March.
This upgrade was necessitated by the state’s requirement that Hinesburg reduce the amount of phosphorus by 75 percent and limit ammonia to 3.5 parts per million in its treated wastewater.
The town will pay for the renovation over 30 years, Bailey said.
Town manager Todd Odit said payment on the debt will be $390,000 a year if the town doesn’t get any subsidies. Subsidies could bring down the payment to just over $182,000 annually.
In the worst-case scenario, if the town is unable to secure other sources of money to pay for improvements, ratepayers could see a jump of 60 percent, Odit told the selectboard.
In the list of Congressional earmarks for specific projects released last week Hinesburg — in fact all of Chittenden County — were left out of that round of funding, he said.
The town still hopes to receive American Rescue Plan Act funds to help pay for this work in a future round to keep down any increase in wastewater rates.