SOUTH SALT LAKE — The finger-pointing was just beginning Monday as the cleanup of the rail car involved in a hazardous materials leak was being wrapped up.

A private company said the 13,500-gallon tanker that leaked Sunday, prompting evacuation of thousands of people and closure of I-15 and I-80, contained a mixture of acetic, phosphoric, hydrofluoric and sulfuric acids. Kennecott Copper owned the tanker but had subleased it to Houston-based Philip Services Corp. (PSC).

Kennecott said Monday the acid cocktail should never have been in its tanker. "They're hauling substances that should not be hauled," Kennecott spokesman Louie Cononelos said.

But PSC also places part of the blame on Union Pacific.

"It appears the rail car was routed, in error, by the transporter (Union Pacific) for three days to Kennecott in Salt Lake City. That transport was done without PSC's knowledge, direction or permission," according to the statement released Monday afternoon.

According to the shipping manifest, PSC spokeswoman Barbara Smith said, the tanker contained corrosive waste, including "N.O.S. (sulfuric acid, hydrofluoric acid)."

Furthermore, 60 percent to 90 percent of the tanker was filled with water, Smith said.

"The rail car was properly loaded, and the contents were listed on its manifest. The materials on the rail car were appropriate for the construction of the car and complied with proper loading procedures," according to the statement.

Sending a small haze of orange gases into the air, the leaky tanker was discovered about 6 a.m. Sunday in the Roper Rail Yard near 2270 S. 600 West. Because officials were initially unsure of the tanker's contents and the health risks it posed, up to 8,000 people were evacuated and parts of I-15, I-80 and U-201 were closed Sunday in the Spaghetti Bowl area.

By 10 p.m. Sunday, the evacuation order was lifted. A specialized machine, brought in from Las Vegas, pumped the remaining acid waste out of the tanker. But even that took several attempts.

South Salt Lake Fire Chief Steve Foote said the strong acids that were eating away at the tanker began eating through the hoses and other equipment being used to pump the material. "These (acids) are all very aggressive when it comes at eating away at things like that," he said.

By 3:30 a.m. Monday, the danger had diminished, so the northbound lanes of I-15 were reopened, Foote said. By 4 a.m., the 7,000 gallons of acid remaining in the tanker had been removed, and by 6 a.m. the entire freeway was re-opened.

A section of 600 West between 2100 South and 2700 South remained closed Monday while the investigation continued.