Residents near the Marathon Detroit Refinery had to evacuate when a fire broke out in a sour water tank at the facility just before 6 p.m. Saturday, authorities said.
The sour water tank fire at the 120,000 barrel per day (bpd) Detroit refinery occurred while the tank was undergoing fueling, according to a notice filed with the U.S. National Response Center.
Marathon said there were no injuries due to the blaze and the refinery continued to operate normally.
Sour water is wastewater from the refining process. As a part of the process, pollutants end up stripped out before the water can either undergo reuse or go out to an outside wastewater system.
Marathon reported the sour water tank involved in the fire contained ammonia, hydrogen sulfide and sulfur dioxide.
The refinery’s private firefighting operation had extinguished the blaze by about 8 p.m., said company spokesman Shane Pochard. Crews were evaluating air quality, Pochard said.
No refinery workers suffered an injury and the appropriate federal authorities are aware of the situation, he said.
Late last year, Marathon completed a $2.2 billion expansion of the refinery — the only one in Michigan. The upgrade allows the company to process heavy crude oils from Canada and increase its daily capacity to 120,000 barrels from 106,000 barrels.