Aqua Illinois has filed for an increase in its water rates that could cost the average Kankakee County consumer an additional $8.08 per month.

The rate increase request was filed Monday with the Illinois Commerce Commission. If approved, the rate increase likely would not go into effect until March 30, 2018, Aqua Illinois president Craig Blanchette said.

Those figures translate to the average monthly bill increasing 15.3 percent — from $52.68 to $60.76, Blanchette said.

There are about 26,000 residential water accounts in Kankakee County and another 3,000 business, commercial and industrial accounts. Statewide, the company has 64,000 water accounts, of which 56,000 are residential.

The current average daily residential cost of water is $1.76. If the full increase is approved, the average daily cost would go to $2.03. The average household consumes 150 gallons on a daily basis, or about 4,500 per month.

But water consumption has dropped. By comparison, that same family consumed 5,223 gallons per month as recently as 2010.

Blanchette said he understands consumers might have concerns regarding the increase, but the system needs to be able to meet growing demands of not only residents, but industry as well.

"Providing water is one of the most capital intensive industries there is," he said. The income would boost annual revenue from Kankakee County customers from $24.3 million to $28 million.

Presenting the case to the ICC will cost the privately-held company about $700,000, Blanchette said.

To illustrate those costs, Melissa Kahoun noted the company is in the midst of a $15 million expansion at the Joseph Donovan Water Treatment Plant along Cobb Boulevard. The expansion will increase Aqua's ability to draw 30 million gallons of water on a daily basis versus 22 million today.

It is estimated 4.5 billion gallons of water flow past the plant on a daily basis.

Since 2016, the company has invested $36 million in upgrades here.

On average, the Kankakee plant supplies 11 million gallons of treated water each day.

If approved, this would be Aqua's third rate hike since December 2010. The ICC approved a 17-percent increase then and an 8.4-percent hike in March 2015.

In addition to the massive renovation taking place at the Cobb Boulevard plant, the company also extended a new water main to the Diversatech campus in Manteno and new infrastructure near the new Interstate 57 interchange in Bourbonnais.

"We are in a good position for economic growth and expansions," Kahoun said. "We want to see this area grow and thrive."

The company has a workforce of 50 in Kankakee. Aqua American, Aqua Illinois' parent company, operates a 40-member call center in the Clock Tower building in downtown Kankakee.

In addition to Kankakee County, Aqua Illinois serves customers in Will, Vermillion, Cook, Champaign, Boone, Knox, Ogle, Winnebago, Lake, DeKalb, Kane and McHenry counties.