Maine on Tuesday joined 14 other states in a lawsuit seeking to force the federal government to adhere to a deadline laid out in the Clean Air Act.

In October 2015, when President Obama was still in office, the EPA raised national air quality standards for smog. The Clean Air Act requires the agency to publicly identify within two years — in this case, by Oct. 1, 2017 — which areas of the country are in compliance with new standards.

But EPA Administrator Scott Pruitt recently extended the deadline for making such determinations by a year. Pruitt in June said that there was “insufficient information” to make the designations and that he would postpone the deadline for doing so until Oct. 1, 2018.

The states are hoping to force EPA and Pruitt to stick to the schedule as laid out by the Clean Air Act. Specific plans and deadlines for mitigating pollution in each area will depend on how new smog standards match up with conditions around the country, according to a statement released Tuesday by Maine Attorney General Janet Mills.

Reducing levels of smog, which is caused by air pollution, would help protect the health of children, older adults, people of all ages who have lung diseases such as asthma, and people who are active outdoors, especially outdoor workers, federal officials have said.

Smog forms in the atmosphere, sometimes far from where pollution sources are located, and can travel long distances, which at times has resulted in air-quality warnings being issued in Maine.

In her statement, Mills cited American Lung Association estimates that indicate in Maine there are more than 24,000 children and 120,000 adults who suffer from asthma, while another 87,000 adults are estimated to have chronic obstructive pulmonary disease, or COPD.

The issue of air quality is not the first that has prompted Mills — a Democrat who plans to run for governor next year — to publicly oppose or challenge policies promoted by the administration of President Donald Trump.

Mills previously has joined other efforts by Democratic attorneys general to block Trump Administration efforts on other environmental proposals and has threatened to sue if Trump rescinds the federal designation of the Katahdin Woods and Waters National Monument in northern Maine.

On Monday, Mills and Maine Public Advocate Barry Hobbins signed a letter along with officials from several other states urging Congress to oppose a Trump proposal to cut federal heating assistance programs for low-income households.

Other states that have joined the lawsuit, which has been filed in federal appeals court in Washington D.C., include California, Connecticut, Delaware, Illinois, Iowa, Massachusetts, Minnesota, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington. The District of Columbia also has signed onto the petition.

Bill Trotter

A news reporter in coastal Maine for more than 20 years, Bill Trotter writes about how the Atlantic Ocean and the state's iconic coastline help to shape the lives of coastal Maine residents and visitors....