Three Maui facilities spewed nearly 190,000 pounds of toxic chemicals into the air in 2015 with the two Maui Electric Co. power plants logging the largest releases in Maui County, the Environmental Protection Agency reported.

The EPA’s annual “Toxic Release Inventory National Analysis,” released Jan. 12 for the Pacific Southwest, showed that a total of 188,500 pounds of chemicals were released into the air in Maui County, most of which was sulfuric acid from the MECO Kahului and Maalaea power plants.

The Kahului Power Plant released 100,000 pounds, mostly sulfuric acid, in 2015, down from 130,000 pounds in 2014. There was a small release of polycyclic aromatic compounds, a possible carcinogen, as well.

The Maalaea Power Plant released 87,670 pounds, up from 79,630 pounds in 2014, according to the report. There also were small releases of benzo perylene (4 pounds), lead compounds (78 pounds), naphthalene (386 pounds) and polycyclic aromatic compounds (202 pounds), all suspected carcinogens.

The Chevron Kahului Terminal, with petroleum tanks and terminals in the Kahului Harbor area, spewed 820 pounds of toxic chemicals, all but 2 pounds of it into the air, in 2015. The terminal released trimethylbenzene (76 pounds), benzene (90 pounds), ethylbenzene (97 pounds), n-hexane (196 pounds), naphthalene (8 pounds), toluene (220 pounds) and xylene (133 pounds). Benzene, ethylbenzene and naphthalene are listed as carcinogenic.

In 2014, the terminal released 739 pounds of toxic chemicals.

A total of 32 Hawaii facilities reported 7 million pounds of production-related chemicals in 2015. Joint Base Pearl Harbor-Hickam was No. 1 on the list with 560,014 pounds of releases.

Maui’s top toxic chemical releaser, the Kahului Power Plant, which was built in 1948, was deactivated in 2014 because the National Pollutant Discharge Elimination System permit for the plant from the EPA was imposing for the first time effluent limits for nutrients from groundwater, which was used to cool the plant and discharged into the ocean. In 2014, MECO said that it could not meet the effluent limits.

In 2013, prior to its deactivation, the EPA report showed 140,000 pounds of sulfuric acid released by the Kahului Power Plant.

Since the 2014 deactivation, the plant’s generators have been reactivated from time to time in emergencies, to cover contingencies and to support the grid during transmission work, utility officials have said.

The plant was officially reactivated late last year to make up for lost power generation from the closing of Hawaiian Commercial & Sugar Co. in December. MECO reported to the Public Utilities Commission that the power purchase agreement with HC&S was terminated Dec. 23.

“With HC&S no longer available to provide power to the electric grid and with Maui residents and businesses continuing to use more electricity during typically peak evening hours in recent years, we’ve needed to run the Kahului units, including K1 and K2, to maintain reliable electrical service,” said MECO spokeswoman Shayna Decker on Friday.

MECO still is planning to retire the Kahului Power Plant by 2022 and no later than 2024, she said.

Decker noted that the MECO plants had a combined decrease in emissions in 2015 compared to 2014 “despite having system peaks of electricity demand grow over those years.”

“We take our responsibility to the environment seriously, and we’ve been working to reduce our emissions,” Decker said.

She pointed to operational changes at the Maalaea plant since 2013 aimed at further reducing emissions and to integrate more renewable energy.

“Through these improvements, we accepted 94 percent of available wind energy in 2016 through November,” she said.

MECO hopes to improve acceptance of renewable energy and is nearing completion of modifications to two heat recovery steam generators at Maalaea. This will allow the generators to operate at lower loads.

“By operating at lower loads, while it does make the generators less efficient, we’re able to take on more renewable resources, like wind and solar, when they are available,” Decker said.

* Lee Imada can be reached at leeimada@mauinews.com.