PORT ALLEN -- Thousands of residents in West Baton Rouge Parish could soon be paying more for sewage. The parish council is set to vote on Thursday on a proposal to raise the sewage rate by 15%, the first increase since 2008.

The West Baton Rouge Parish Utilities Director, Adrian Genre, says that the increase is needed to help maintain and/or replace aging sewage treatment plants.

"The life expectancies of these plants are about 30 years, and some of those plants have hit that and even far exceeded it; some are approaching 40 years," Genre said.

Genre was asked how much the average family's sewer bill would increase.

"An average residential household uses about 6,000 gallons, roughly, again some more, some less. Your sewer fee is based on your water consumption. That 6,000-gallon-a-month water consumption is going to result in about an increase of $3.54 a month," Genre said.

The increase comes following the parish receiving multiple grants for consolidated sewer projects.

"It's a grant program. We went through the water sector program, and it was a $10 million grant that we received for a consolidated sewer project. It's going to eliminate 10 individual treatment plants. We got $10 million awarded to us for that," WBR Parish President Jason Manola told WBRZ.

Manola said that when a parish receives this type of funding from the water sector program, a team is assigned to do a state-sponsored rate study.

The study recommended a 95% increase in the parish sewage rate for the project to work. Manola pushed to lower the rate increase, getting it down to 15%.

"I had our council approve a resolution dedicating a certain portion of the sales tax dollars that our general fund gets to help offset that increase so we wouldn't have to pass that along to the customers," Manola said.

Not every resident will be affected by the rate increase if it were to pass.

"This is only for the people that are on West Baton Rouge parish sewer, so if you have like your own treatment plants or Mo-Dad systems or things like that, it doesn't impact them whatsoever," Manola said.

Manola was asked what the extra money from the increase would be used for.

"It's going to be used for the regular operational costs of actually running, not just all of the new sewer treatment facility, but all of our treatment plants and so forth," Manola said.

Cities like Port Allen that have their own sewage systems also had to raise rates this year.

"It actually just increased to about $4.60 for residential and about $5.50 more for commercial accounts. Wasn't a big increase, but of course it's noticeable to our customers," Port Allen Mayor Terecita Pottan said.

The increase came as a surprise to residents, but many told WBRZ the increase could've been a lot worse.

"90ish percent, you're paying double. That's a big break with the economy as it is right now. 15 percent. That would be tough to tackle," West Baton Rouge resident Ed Shinn said.

If the parish council approves the ordinance, Genre says the increase will more than likely appear on the May billing.