PITTSBURGH — The summer blend of gasoline that is aimed at reducing emissions may come to the end next year.

Drivers in Butler County and six other Western Pennsylvania county see gas prices rise each summer due to a regulatory requirement aimed at reducing emissions, but that could change next year.

Officials decided in 1999 to require gas stations in a seven-county region around Pittsburgh to switch to a summer blend of gasoline from May to mid-September.

The state House approved a bill Monday to seek an end to that regulations, and the state Senate approved House amendments to its measure on Wednesday. If approved, the change would have to be approved by the federal Environmental Protection Agency.

The EPA regulates gasoline sold in the summer months to reduce emissions that contribute to ground-level ozone, the main component of smog.

State Sen. Elder Vogel Jr., R-Beaver, said the requirement has meant a 10- to 15-cent increase in gas prices per gallon in the region compared with neighboring counties and Ohio.

“I think we don’t need it anymore. It was a hidden tax basically on the seven counties in southwestern Pennsylvania,” Vogel said.

The legislation would eliminate statutory requirements for low Reid vapor pressure gasoline in Allegheny, Armstrong, Beaver, Butler, Fayette, Washington and Westmoreland counties during the summer.