WASHINGTON — The Environmental Protection Agency should pull back its proposed rule to limit greenhouse gas emissions from existing power plants and make revisions so it will be less costly to consumers, rural electric power companies CEOs say.

In June, the EPA proposed cutting carbon pollution by putting new limits on coal-fired power plants in an attempt to shift to more low-emitting and renewable energy sources. EPA wants coal-based power plants to become more efficient by burning less fossil fuel and installing improved pollution-control equipment.

“We oppose the EPA regulations because they are going to raise electric rates, threaten reliability and are illegal under the Clean Air Act,” Jo Ann Emerson, CEO of the National Rural Electric Cooperative Association, said in a conference call Monday.

America’s rural utility cooperatives provide electric power for 12 percent of the country – many of them farmers, homeowners and small business people — and generate nearly 5 percent of the total electricity produced in the U.S. each year.

For electric coop members, the proposed rule would require increases in electric rates of more than 10 percent on average by 2020 — and more than 17 percent by 2025, according to analysis by Emerson’s organization, the NRECA. Emerson is a former Republican congresswoman from Missouri.

A report released by the Electric Reliability Council of Texas maintains that power prices in Texas could increase more than 20 percent under the new caps. That means a $120 rise in the monthly bill for a mid-size family living in an inefficient home — in terms of energy use– said Kerry Kelton, CEO of Mid-South Synergy.

Companies are also concerned that the EPA rule could weaken reliability by forcing some coal-fired power plants to close before the renewable power sources infrastructure is fully developed.

EPA also wants to increase the existing and under-construction natural gas capacity by as much as 70 percent.

Lisa Johnson, CEO of Seminole Electric Co-op, Inc. in Tampa, Fla., said a growing need for natural gas would cause prices rise.

“Without fuel diversity, we will become captive to the price and physical supply volatility of the natural gas market,” Johnson said. “Florida will certainly feel the pain as the cost of electrify from natural gas spikes.”

EPA has not done a cost-benefit analysis of its rule.

According to a blog posted on the EPA website, the proposal drew more than 1.6 million comments from the public by the Dec 1 deadline. The EPA will review those public comments as it works to finalize the rule, Enesta Jones, press officer of the EPA, said in an email.