Greater Sudbury's main sewage treatment plant is a busy place this fall, with about $75 million in construction going on.

A big part of it is the $63 million plant for processing sewage sludge that, for decades, has been dumped on the tailings ponds near Lively.

But the plant is also getting upgrades that will allow it to better handle more water and improve the filtration of garbage that Sudburians flush down the drain.

Mike Jensen

Plants supervisor Mike Jensen points out some of the 12 million dollars worth of upgrades being done right now to the Kelly Lake treatment plant in Sudbury. (Erik White/CBC)

Wastewater plants supervisor Mike Jensen said hair, dental floss and even bacon grease jam up the plant.

Condoms, rags, and needles are also flushed by Sudburians and eventually float into the plant and clog up the works.

That makes it hard for the city to process Greater Sudbury's waste efficiently and cheaply — especially during a major rainstorm or melt.

"In times when there's high flows due to weather … [a plugged valve] creates its own dam and I can't move that water where it needs to go,” he said.

Brad Johns

Greater Sudbury facilities engineer Brad Johns stands outside the sewage treatment plant's "head house" that's getting a $12 million upgrade. Upgrades to the treatment plant will be complete in December 2014. The plant will be running at full capacity early in the new year while construction continues on its the new biosolids plant. (Erik White/CBC)

When there is more water in the system than it can handle, staff are forced to "bypass" it — meaning it skips several steps in the cleaning process and the unfiltered waste goes into Junction Creek out the back of the plant.

It happens about twice a year — much less than it used to — but Jensen said it's still something staff hate to do.

"You know, we don't want to pollute. Ultimately, we don't want to bypass,” he said. “We're always like 'What are we going to do, what are we going to do, we got to make a decision. Are we going to hold it off?’"

Jensen said that decision will hopefully be made less often once construction is complete in the new year, when the sewage treatment plant will be back to full capacity and able to handle about twice as much water as it can now.

The new biosolids plant isn't slated to open until 2015.