DOWNEY - Downey Auto Wholesale, located at 7255 Firestone Blvd., is being investigated by Los Angeles County Health officials after local public works personnel discovered a trail of hazardous waste flowing from the dealership to the Rio Hondo River on Tuesday.During a routine inspection of the river bed on Tuesday afternoon, LA County Public Works staff noticed a sheen on the surface of the water that was later determined to be hazardous materials, including both oil and antifreeze. According to Chuck Seely, assistant chief and fire marshal for the city of Downey, LA County investigators linked the waste to the Downey auto dealership, just one mile east of the river, after discovering a trail of oil flowing into the storm drain near the business. "They were actively pouring it in the hole when investigators arrived," Seely said. 'They're telling investigators that they thought there was a grease separator underground, but prosecutors are looking in to it." Seely said LA County Public Works conducted an extensive clean up following the discovery where various pipes, drains, and the river bed itself, had to be sanitized. "It was a very expensive cleanup - tens of thousands of dollars," he said Thursday. "But this is not about retribution - it's about doing what's right by environmental laws. If you pour something down the drain, it ends up in the ocean. We're just glad this didn't happen during the six-inch rain storm. It would've been gone - we wouldn't have been able to find it." Downey Auto Wholesale, a used car dealership, which just opened last December, would not comment directly on the matter, but did say they were complying with officials, handling the case through appropriate channels. LA County Public Works officials and Lee Kirby, head of the Downey Fire Department's Health and Hazardous Materials division, are currently investigating the case.