HOUSTON, March 25 (Reuters) - A man who said he was injured in an explosion at Valero Energy's ( VLO ) Port Arthur, Texas refinery on Monday night filed a lawsuit on Wednesday in a state district court alleging the company failed to properly maintain the refinery.

The lawsuit filed in the Jefferson County District Court in Beaumont, Texas, seeks more than $1 million in damages.

A Valero spokesperson had no immediate comment on Wednesday night.

In a filing to the Texas Commission on Environmental Quality on Tuesday, Valero said: "An unforeseeable release of process fluid in Complex 2 resulted in an ignition event and multiple process unit upsets."

Jonathan Jaimes was at the Port Arthur refinery when a diesel hydrotreater exploded, shaking homes as far as 11 miles (18 km) away from the plant on the east Texas border with Louisiana.

"(Jaimes) played no role in the tasks or events leading to the explosion. The blast and heat from the fire of the explosion caused (Jaimes) to be thrown to the ground and injured, as a result of the explosion," according to the lawsuit.

Jaimes sustained injuries to his back, neck and spine and other parts of his body, the lawsuit said. He also suffers from post-traumatic stress disorder.

"This was not an unavoidable accident - it was the result of gross negligence and a flagrant disregard for worker safety," Kyle Findley, an attorney at Arnold & Itkin, which is representing Jaimes, said in an emailed statement.

"Valero had awareness of the risks at this facility and chose to ignore them," Findley said. "When a company shows that kind of disregard for the safety of its workers and the surrounding community, it must be held accountable."

Jaimes declined to comment, when approached through a spokesperson at law firm Arnold & Itkin.