HF Sinclair will pay a fine and implement a two-person verification system after a human error caused more than 300,000 gallons of contaminated gasoline to be distributed throughout the Front Range in January.

The gasoline company will pay a fine of $365,694 — one dollar for every gallon of contaminated gasoline sold — and agreed to use a two-person verification system to oversee product transfers in its Henderson terminal, officials with the Colorado Department of Labor and Employment’s Division of Oil and Public Safety said Friday.

More than 1,000 people have submitted complaints saying they filled up with the contaminated gas on Jan. 8, the officials said. Those affected saw up to thousands of dollars in repair costs as mechanics had to flush tanks, clean fuel injectors and check spark plugs, auto repair professionals have said.

“We are going to work with (Sinclair) on trying to make sure we have ongoing monitoring of fuel quality with them,” said Zach Hope, a program manager at the division, on a media call Friday. “It’s an important thing to make sure that we are having a good integrity of the fuel coming out of that location moving forward.”

The division released its findings report on Friday detailing how a manual valve connecting both gasoline and diesel pipes to an external tank at Sinclair’s Henderson terminal was partially left open while the facility was receiving a pipeline diesel shipment around 2 p.m. on Jan. 7, diverting some of the incoming diesel into the gasoline tank.

That diversion resulted in nearly 1.7 million gallons of regular unleaded gas being contaminated with diesel fuel before the error was discovered around 6 a.m. the following day, according to the report, but not before about 365,694 gallons of that contaminated fuel had been sold and delivered to 49 gas stations throughout the Denver area and as far south as Colorado Springs.

Even though they were aware of the issue the morning of Jan. 8, Sinclair did not notify the public of the error until the division reached out to the organization the following morning, according to the report.

Some of the affected gas stations saw on float sensors that the fuel they received that day wasn’t of the usual quality before Sinclair had recognized the issue, Hope said. Their automatic sensors are required by state law, he added, whereas terminals such as Sinclair’s are federally regulated. Federal rules do not require automated monitoring of such facilities.

“While we’ll continue the conversation of what the state can or should do differently with our laws or regulations, this (change) will largely be a federally regulated operation,” Hope said. “That’s outside our jurisdiction.”

Anyone who has not yet filed a complaint with the division can do so using its consumer complaint form.