At AES Hawaii's power plant at Campbell Industrial Park early Wednesday morning, front-end loaders were scooping up coal ash in the dark and dumping it into a trailer, creating a huge dust cloud that drifts off site and settles on nearby businesses.
The ash is part of a mountainous stockpile of coal and other materials that were burned in AES Hawaii's plant, the state's largest independent power producer.
Nearby businesses complain that AES isn't doing enough to contain the coal ash, forcing workers to breathe in the material.
"Coal ash has a lot of toxic chemicals in it like arsenic, lead, heavy metals. It increases the risk of cancer when you have people breathing in coal ash," said state Sen. Josh Green, who also is an emergency room doctor.
"These particles can get up in the air and then they get inhaled. We can't have that."
The U.S. Environmental Protection Agency considers coal ash a non-hazardous solid waste.
Jeffrey Vaughan, AES Hawaii's plant manager, said that the company manages the material in accordance with environmental regulations and requirements.
Vaughan said the company prevents drift by using water trucks to spray the ash when it's being loaded. They also water down their driveway and nearby roads.
"AES not only meets all applicable local, state, and federal regulations, but we strive to exceed them," he said.
Under its permit with the state, AES Hawaii is allowed to stockpile up to 37,000 tons of ash on its property. The permit requires dust screens and the company is required to prevent the ash from leaving the area.
Some say that's not enough.
"All of my readings suggest that you have to have total containment," Green said.
Environmental activist Carroll Cox recently filed a complaint with the Health Department, which is looking into the matter.
Cox said when the company sprays water on the ash on the roads, it flows down the curbside and into a storm drain, where it can get into the area's waterways.
Hawaii News Now also took video of coal ash covering the floor of a nearby company's work area. Some of the employees complained that the dust makes them cough constantly and gets into their workplace and cakes onto their cars.
Cox said there's no question the ash is not being controlled.
During the past week, he shot dozens of videos, some at night, showing how the company loads tons of coal ash in its yard. Much of video shows how the dust gets blown off the property by the wind.
"You could see a tower of ash and a tower of coal dust just drifting and pluming up," Cox said. "When you see the plumes of smoke or dust flying to the ocean, it becomes quite concerning."