Texas has filed a lawsuit against oil companies Shell and PEMEX, alleging that the fire at a Houston chemical plant in May released airborne contaminants that caused environmental damage.

The fire began at the Shell Company chemical plant in Deer Park on May 5 and continued to burn for three days before it was eventually put out.

Harris County Sheriff Ed Gonzalez said the fire began during routine maintenance because of the heat exchange between two heavy oils, as previously reported by The Dallas Express.

The Texas Attorney General’s Office, on behalf of the Texas Commission on Environmental Quality, filed the lawsuit on August 7 in Travis County, reported The Wall Street Journal. The lawsuit seeks more than $1 million in compensation for alleged environmental violations that occurred during the fire.

Multiple statutes were allegedly broken during the fire and subsequent clean-up efforts, including the Clean Air Act, Solid Waste Disposal Act, and the Water Code, reported the Houston Chronicle.

“Vast quantities of water” were used to put out the fire, resulting in over 68 million gallons being “unlawfully discharged into the Houston Ship Channel,” according to the lawsuit, per The Texas Tribune.

The lawsuit further alleges that the discharge of polluted water began on the day the fire started, May 5, but continued for weeks afterward, lasting until May 26. It also states that “mass quantities of air contaminants were emitted into the environment, including huge plumes of black smoke along with large flames from the Plant’s flares,” according to the WSJ.

Natalie Gunnell, a spokesperson for Shell, said the company does not comment on ongoing litigation.

“The Deer Park chemicals facility remains in a recovery phase as we continue to investigate the cause of the fire and rebuild the damaged portion of the plant,” she said, per the Houston Chronicle.

Jennifer Walsh, communications director for PEMEX Deer Park, said the company has been working to protect those who may have been affected.

“Ever since the fire occurred at Shell Chemical LP’s Deer Park plant in May, our company has committed to working cooperatively and proactively with the Texas Commission on Environmental Quality and other regulatory agencies to resolve any concerns they may have,” Walsh said, according to The Texas Tribune.

Shell is also facing several lawsuits from employees and contractors who claim they suffered injuries or health complications from the fire, per the Houston Chronicle.