Relief from a stink emanating from Batavia's sewage treatment plant is coming.

Aldermen Tuesday agreed to spend up to $40,000 to install a temporary filter on the exhaust system of the sludge treatment building until a construction project is finished this fall.

People have complained for several months about an occasional bad smell wafting over the downtown.

The Public Works Department has determined it is due in part to the anaerobic digesters being taken out of service during the expansion of the plant.

The anaerobic digesters are enclosures where bacteria break down solid waste sludge. The city is rehabilitating the digesters, and constructing a new digester operations building.

In the meantime, a more raw form of sludge is being processed in the sludge treatment building, leading to smellier gas exhaust.

The city is spending about $30 million on the first of three phases to expand the plant, replace some of its buildings and increase its ability to remove phosphorus from sewage.

Aldermen debated whether it was prudent to spend the money to fix a problem that will be gone in September. "Depending on the day it can be horrible," said Alderman Scott Salvati, who works near the plant. But he said "I'll hold my nose," given Batavia is trying to save money because of the loss of sales tax from the closure of the Sam's Club store.

"I felt the same way right up to the point where the next four, five months are spring and summer," Public Works Director Gary Holm said. There would be more people out and about in downtown, including on the Fox River Trail, which runs past the treatment plant.

Salvati and other aldermen then agreed that Batavia's downtown could get a reputation for being a place that stinks, and that visitors who have a bad experience may not return.

"It (the device) is not going to eliminate every odor," Holm said. "We are trying ... to mitigate the most obvious and urgent source." One day, a bad odor was traced back to a blocked sewer grate.

And algae blooms can make the Fox River smell bad.

"We do have a natural river running through downtown, and sometimes Mother Nature produces odor," Holm said.