Pennsylvania American Water, which serves about 42,000 customers in Butler County, is asking state regulators to approve a price increase of more than 11 percent for residential water to fix its crumbling infrastructure.

The rate increase, if approved, would cost Pennsylvania American customers about a penny more per gallon, tacking an extra $6 per month onto the water bill of the average county resident. The utility’s last rate increase was one of 6.3 percent in 2011.

Pennsylvania American told the state Public Utility Commission (PUC) that it needs money to repair pipes, pumping stations and water storage tanks. The company has about 300 miles of water main in the county, according to PAW spokesman Gary Lobaugh.

Between its rate increases in 2009 and 2011, Pennsylvania American spent more than $16 million in county upgrades, Lobaugh said. Since 2011, the utility has invested about $25.2 million in improvements, including reconstruction of the spillway at Oneida dam and reservoir, and replacement of aging and undersized water mains.

“We’re not immune to the same increasing costs other businesses incur,” Lobaugh said.

He said Pennsylvania American expects a response from the PUC this summer.