The EPA said Hamakua Energy Partners was failing to meet state and federal Clean Air Act permit requirements, including limits on emissions and monitoring.

Hamakua is the largest power generator on the island and sells electricity to Hawai'i Electric Light Co.

"Clean Air Act rules are very clear on the need for both appropriate emissions limits and continuous monitoring of power plant emissions," said Deborah Jordan, director for the EPA's Pacific Southwest Region's air division. "We will continue to ensure that facilities comply with these regulations and do their part to protect air quality."

Hamakua owns a power plant in Haina, Hawai'i, that has two 23 megawatt combustion turbine generators. The facility was constructed in 1999 and is a major source of island air pollution.

Quarterly compliance reports submitted to the state Department of Health by the company identified instances from 2001 to 2003 where facility emissions exceeded nitrogen oxide levels in the permit. The reports also identified instances where the carbon monoxide monitoring and opacity monitoring systems failed to operate for both generators, the EPA said.

Hamakua also failed to submit required quarterly reports to the EPA.