This story was originally published by Honolulu Civil Beat . Hawaiʻi has some of the freshest air in the nation, but in some parts of the state hazy skies can impact tourism and public health.  Now, the U.S. Environmental Protection Agency has pumped the brakes on a multi-decade effort to improve visibility and reduce fine particulates and other man-made pollutants. On May 15, the agency announced it had partially denied Hawaiʻi’s 2024 Regional Haze State Implementation Plan, a detailed proposal that lays out the state’s intention to comply with the federal Clean Air Act. The plan was designed specifically to reduce haze in two iconic places: Hawaiʻi Volcanoes National Park on the Big Island and Haleakalā National Park on Maui.…