More than 24 hours after igniting Monday, the Magnablend fire was still smoldering.
While the smoke has an awful odor, continued Environmental Protection Agency air quality tests show it does not pose a public health threat.
"It's a fire," EPA Coordinator Nicolas Brescia said. "But the things that are coming off this site that would pose a public health threat -- we're not detecting anything significant."
But the runoff from the water firefighters used to douse the blaze is a concern. The water is now gathered in ditches near the site.
"We had our public works department come in and bring in sand and back hoes, and what they did is they dammed it up where the water goes under the road in front of the college," Waxahachie Fire Chief David Hudgins said.
Magnablend owner Scott Pendery said that 80 percent of what his company produces are oil and gas products. But he said he could not say exactly what chemicals are in the runoff, or floating in the air.
"We have about 200 different raw materials that are in our facility," he said. "We make about 100 different blends, so it's a constant movement between the seasons and what products are being made."
But Pendery said that whatever products are in the runoff or in the air don't seem to be harmful.
"The EPA and TCEQ have been doing constant monitoring," he said. "And, other than the smells, there is nothing toxic they've found, which is wonderful. And we’re grateful for that."
Preliminary testing on the water showed similar results to the air quality.
"Two minor compounds were the only things that were detected, and they were very low levels," said Jeff Kunze of the Texas Commission on Environmental Quality.
But dark brown spots are proof something is in the water, so vacuum trucks are collecting it.
"That water will be recovered," Brescia said. "They'll be running waste analytical on it to figure out what it is and where it can go, and then it will be properly disposed of."
Pendery said investigators believe an electrical spark caused the initial fire.