"They had it all picked up late Saturday, early Sunday, and the rain we've had since then should have diluted it more," said Jerry Fleenor, the Sullivan County Emergency Management Agency director.
About 100 gallons of Ultra Sheen leaked into the creek about 11:40 a.m. Saturday when the truck driver hauling it down Interstate 81 lost control of his rig and went over the overpass at Highway 394.
Ultra Sheen is a glazing substance that makes the newsprint used for magazines shiny and slick.
Fleenor said four of the six 350-gallon containers came out of the truck, and "one had a pretty big hole."
He said there was about 50 gallons left in the container, which meant about 300 gallons spilled out.
Only a third of that made it into Reedy Creek before emergency responders could stop the flow.
"Based on what the product maker says, it's soluble, so it diluted in the water and made a milky substance," Fleenor said.
There was a possibility of very small fish dying from the spill, but Fleenor had no reports of any kills.
According to the Tennessee Highway Patrol, the truck driver, Danny L. Stephens of Nashville, said he sneezed and blacked out just before the crash.
Stephens, who was traveling north on I-81, crossed the median, became airborne and went over the guardrail onto the westbound lanes of Highway 394.
No other vehicles were involved in the crash, but during the cleanup there was a head-on collision at the site after a woman went around a blockade and traveled the wrong way on Highway 394.
No one received serious injuries, officials said.
As for the substance spill, Fleenor said there shouldn't be anything for residents to be concerned about now, but "if anyone is on a well within a mile of the wreck, they may want to have their water tested to be sure."
Fleenor said he did not believe there were any residential wells in that area.