The Environmental Protection Agency released a final ruling Wednesday, changing the language within the Clean Air Act to allow the continued use of less-advanced diesel generators in rural Alaska.

The ruling allows for the revision of the Clean Air Act New Source Performance Standards for Stationary Compression Ignition Internal Combustion Engines and is the result of a bill of similar nature passed by Congress in September.

The bill, titled the Alaska Remote Generator Reliability and Protection Act, sponsored by Alaska Republican Sen. Dan Sullivan, sought to exempt rural Alaska from required adherence to what have been considered by some to be the strict air-quality regulations upheld by the EPA.

At the root of the issue are the so-called Tier 4 restrictions, put in place by the EPA in the 1990s, on the particulates found in diesel exhaust.

Many communities throughout rural Alaska rely almost entirely on diesel engines for electricity and heat. Diesel heating fuel is exponentially more expensive in rural areas of the state and the additional cost of needing to continually update generators with aftermarket emissions controls can often be financially crippling to smaller remote communities.

The recent EPA ruling allows the rural communities to meet only the Tier 3 standards. The ruling will still require the installation and use of new Tier 3 machines. While the previously required Tier 4 engines are more advanced and able to reduce emissions, the engines are typically more complicated to operate and maintain. The engines also require the use of filters, which add to machine maintenance and are not often readily available in remote areas.

While this will mean that these areas of the state will be allowed to release more diesel pollutants into the air, the goal, the EPA release stated Wednesday, is to increase affordability and reliability of energy in areas of rural Alaska.

“Having operated utilities in rural Alaska for over 25 years, I know firsthand that power reliability challenges are significant even without more stringent regulations. Today’s commonsense approach will allow utilities to provide power more reliably while ensuring older units can be replaced with newer more efficient diesel engines. This is a success story for rural communities operating off the grid,” said Chris Hladick, administrator of EPA Region 10.

President Donald Trump signed the bill Oct. 4, a significant step in the deregulation process Sullivan celebrated in a statement released shortly afterward.

“Prior to this bill being signed into law, rural communities in Alaska that were isolated from the power grid were shouldered with overly burdensome federal rules that jeopardized access to reliable and cost-effective electricity,” Sen. Sullivan said. “I want to thank the president for signing this bill into law to help ensure that rural Alaskans can safely heat and power their homes in time for the quickly approaching winter season.”

The bill also also requires the EPA to instruct Congress on options for the federal government to assist remote areas of Alaska with meeting their energy needs in an affordable and reliable manner.

Contact staff writer Erin McGroarty at 459-7544. Follow her on Twitter: @FDNMPolitics.