Lexington sewer bills will go up starting July 1. Find out how much and why.

It will cost more to flush toilets in Lexington starting July 1.

The Lexington-Fayette Urban County Council voted unanimously Thursday to increase sewer rates by five percent during each of the next two years. Sewer rates normally only increase 2 percent each year.

The average residential bill will increase from $28.57 to $30, a $1.43 monthly increase. By July 1, 2020, the average bill would climb to $31.50, according to figures the city previously provided the council. Those calculations are based on average sewage usage of 4,000 gallons a month.

City officials have said the rate hike is needed to help pay for more than $590 million in sewer and storm water upgrades required under an Environmental Protection Agency consent decree to improve water quality. The last time the city raised rates by more than 2 percent was in July 2015, when rates increased by 12 percent. In 2008, when the city first entered into an agreement with the EPA, rates went up 48 percent.

The city has been able to shave more than $95 million from projected costs for the upgrades performed so far, which include 10 wet weather storage tanks, replacement of aging sewer lines, and upgrades to treatment plants and pump stations.

But costs are climbing. More than $40 million in sewer line replacement projects began this spring, many of which are coming in over budget, city officials have said.

City officials have previously said Lexington’s sewer rates are in line with surrounding cities.

Based on an average sewage usage of 4,000 gallons a month, Louisville, Irvine, Lawrenceburg, Richmond, Winchester and Frankfort will still have higher monthly bills than Lexington, according to figures provided by the city. Many of those cities, including Louisville, Winchester and Frankfort, are also under EPA consent decrees to upgrade their sewer and stormwater systems.

Average monthly bills in Berea, Bowling Green, Georgetown and Harrodsburg will be lower. Those cities’ average monthly bills are less than $30. Georgetown’s is $18.98, the lowest in the region.