Officials say that the type of crude oil that was spilled is like candle wax. Once it gets hotter, it spreads and may spread into our drinking supply.
The accident happened Wednesday at 6:15 in the morning. The semi that hit the tanker was travelling at 65 mph on Interstate 80.
"Multiple people were transferred to the hospital, " said Unified Fire Authority Capt. Bryan Case.
Two people were taken to an area hospital.
"He was slightly above the speed limit but the fact is he was traveling too fast for the car in front of him and he rear-ended a semi," said Sgt. Steven Manful of the Utah Highway Patrol.
UHP says 105 barrels or nearly 4,500 gallons of the petroleum based crude oil was dumped onto the roadways and ended up in a near by stream.
"It appears at this point it has been contained at the junction of this creek and this draw," said Kevin Okleberry with the Salt Lake County Health Department.
The water way leads to the Mountain Dell Reservoir, which is a main source of drinking water for Salt Lake City, but officials say the spill has so far been contained before reaching the reservoir.
"Because this is heavy crude and it does not have many light fractions in it, it does not appear that it is getting picked up and taken down," Okleberry said.