Delaware County will officially oppose planned changes to the Environmental Protection Agency’s expanded definition of “waters of the United States” under the Clean Water Act.

Commissioners last week voted in favor of a measure to formally oppose the implementation of a rule change that would broaden the Environmental Protection Agency’s jurisdiction.

“It really is in line with the opposition that our national association of counties has expressed against the proposed adoption within the next few months,” said Tim Hansley, the county’s administrator.

Under the current incarnation of the 43-year-old Clean Water Act, “waters of the United States” are defined as those which are “navigable.”

However, changes to the language could include smaller bodies of water, including streams and wetlands.

County officials have said the changes could stymie development and lead to costly compliance.

“Unfortunately, the federal EPA has overreached,” said Commissioner Barb Lewis.

The proposed changes are also opposed by the Delaware Soil and Water Conservation District.

In a letter to federal lawmakers, the organization called the proposed changes “vague and nebulous.”

“America’s farmers need operational certainty in order to provide food, fiber, fuel and forage as well as clean water for all of us to keep this nation great,” the letter reads.

The EPA has said the changes are necessary to protect the nation’s supply of drinking water.

“We need clean water upstream to have healthy communities downstream,” the federal agency says on its website. “The health of rivers, lakes, bays and coastal waters depend on the streams and wetlands where they begin. Streams and wetlands provide so many benefits to communities by trapping floodwaters, recharging groundwater supplies, filtering pollution and providing habitat for fish and wildlife.”