(NewsNation) — Videos shared online of a creek in East Palestine, Ohio, clearly show a colorful sheen following a toxic spill.

It’s been two weeks since the Norfolk Southern train carrying toxic chemicals derailed in the town, and many community members are still looking for answers about whether the water is safe.

Chemical engineering professor at Dr. Eric Beckman said there’s no way to really know the answer to that question without more testing, but added that residents have a right to be concerned.

“You’ve probably seen that rainbow before, if you see a puddle in the road,” Beckman told NewsNation. “Whenever you see that, you know you’ve got a thin layer of something organic. … It could be anything from gasoline to butyl acrylate.”

The frustrating part about the train derailment, according to Beckman, is that any number of chemicals could have been released during the crash and controlled explosion that followed.

“It’s a monumental job to try and figure out what all was there,” Beckman said.

Beckman said if he were an area resident, well water would be his number one concern.

“I would be very concerned if I was using a well as my primary water source and I lived in that area, I would probably have my own tests done or pay someone to do them,” Beckman said.

Moving forward, Beckman hopes toxic chemicals like vinyl chloride, which officials burned in the days following the crash, are no longer transported via train cars.

“That stuff is so dangerous. When you think about it, they prefer to do a controlled explosion and burn because they were so afraid that this stuff would go into the air as a vapor,” Beckman said, adding that the vapor could be deadly.