Kennewick's efforts to reduce the fats, oils and grease in the city's sewer system appear to be working.

The amount of the gunk that can block sewer lines and clog manholes already has decreased by 25 percent in the last year, said Gary Deardorff, the city's utility services manager, during Tuesday's city council meeting.

That reduction means a cost savings for the city and its residents, he said. The city can now clean lift stations less frequently, and may be able to clean manholes in commercial areas less often as well.

The city spends about $123,000 a year to remove fats, oils and grease from sewer lines and city wastewater treatment facilities.

A change to city code approved last year brought the city's pretreatment code up to current federal and state requirements, Deardorff said.

In 2012, Chris Espinoza, who was recently promoted to wastewater supervisor, did 422 pretreatment inspections and helped 50 food service establishments determine what they need to do to get into compliance, Deardorff said.

Education is the focus, which includes suggesting throwing food scraps in the garbage instead of using a food disposal, he said.

This year, Deardorff said the city has contacted 65 businesses that do not do any pretreatment.

Businesses have been given until March 1, 2016, to come into compliance with Kennewick's requirements for pretreatment, he said.

So far, the feedback has been positive.

The code revision also prepares the city for industrial development in the urban growth area, he said.

One of the city's goals for this year is to develop a partnership that will allow used cooking oil to be recycled, with the revenue then going to the Kennewick Kares program, which helps low-income city residents pay water and sewer bills, Deardorff said.