BANGOR, Maine — Residents might catch a whiff of something unpleasant over the summer as the city’s wastewater treatment plant replaces a vital piece of its infrastructure.
This week, Auburn-based T Buck Construction launches a $2.3 million project to replace the plant’s biofilter media system and repair the tower that contains the system.
Andy Rudzinski, director of the plant, issued a news release Monday announcing the start of work and warning residents and commuters that “there may be times when odors may become apparent.”
“At worst, these may be reminiscent of an earthy tone, similar to low tide along the coast,” he said. “We apologize in advance and ask your patience.”
The project is expected to continue throughout the summer, Rudzinski said, adding that the plant would do “everything in its power” to contain and control the odor.
The tower is filled with eight layers made up of blocks of biofilter media, which resemble honeycomb. Stacked on top of one another, those eight layers are about 16 feet thick. If you were to flatten out the layers, the plastic would cover about 104 acres.
All that surface area provides room for microorganisms to grow and intermingle with wastewater. After flowing into the plant, the stormwater and sewage has solids, sand, oils and other materials removed before the liquid is sprayed onto the filters. The microorganisms growing in the biofilters feed on the waste and continue the process of cleaning the wastewater until it’s clean enough to flow into the Penobscot River.
The projected lifespan of the biofilter is about 12 years, but most layers in the Bangor tower have been working nearly around the clock for 23 years. Only the top layer has been replaced — twice in the past two decades. That top layer suffers the most wear and tear because it’s exposed to the sun and elements.
While the tower is shut down, Rudzinski said the plant would continue to pump out water that meets federal and state quality standards.
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