NASHVILLE (AP) — Nine years after the EPA first found Tennessee's Eastman Chemical Company was polluting the air with unsafe levels of sulfur dioxide from its coal-burning power plants, the state is still working to bring the company into compliance with national air quality standards.

That's according to a new state audit of the Tennessee Department of Environment and Conservation, released to the public this week, that also found continuing problems with the department's data management.

The Environmental Protection Agency tightened its standards for sulfur dioxide emissions in 2010, saying the new limits were "necessary to provide protection of public health with an adequate margin of safety, especially for children, the elderly and those with asthma."

The agency designated the area around the Eastman Chemical Company, in Kingston, out of compliance in 2013. To meet air quality standards, the Tennessee Department of Environment and Conservation worked with Eastman on a plan that included converting five of the company's 14 coal-fired boilers to natural gas.

But in 2019, air monitoring at a nearby elementary school found sulfur dioxide levels were still too high. The department is in the process of submitting a new plan to the EPA that includes emission controls on two of Eastman's remaining coal-burning boilers. According to TDEC documents, Eastman put in temporary controls in mid-2019 and finished installing the permanent controls late last year.

"The department's Air Pollution Control Division has been working with the Environmental Protection Agency for nine years to lower the sulfur dioxide release levels around the Eastman Chemical Company facility in Kingsport and must continue until attainment is achieved," the newly released audit by the Tennessee Comptroller of the Treasury states.

In a statement to The Associated Press, Eastman said preliminary air monitoring data for 2022 shows the new controls will bring sulfur dioxide down to safe levels. The company also said it is in the process of replacing three of its remaining coal-fired boilers with new natural gas ones, further reducing emissions.

"We take our commitment to operating responsibly very serious, and we continue to do our part to reduce risk and emissions to ensure the safety of our local community," the company said.

Eastman said it provides its own power and heat through a process called cogeneration, which is more efficient than producing each separately, and its output would power a city the size of nearby Knoxville, home to about 190,000 people.

The audit also looked at whether data management problems identified in a 2018 audit of the Department of Environment and Conservation were resolved. At that time the environmental divisions were storing information in any of 161 different places, including paper files. The ensuing mess left auditors unable to determine whether the department was adequately addressing environmental concerns.

While some problems persisted, they were not as drastic.

Auditors looked at a sampling of environmental complaints submitted to the department's six divisions. They found the remediation division did not have policies and procedures in place that would allow auditors to test complaints. Of the 60 complaints sampled, 31 were for the water division, and 19% of those contained errors.

"Incorrect information entered into the system prevents management from being able to effectively monitor the true status of complaints," the auditors wrote.

The department received a $15 million budget allocation last fiscal year for improvements that are expected to take up to five years to implement.