A fuel spill that sent 1,200 gallons of diesel into the Palouse River near Pullman on Monday has state regulatory officials urging owners to check their tanks.

The spill was discovered Monday morning by Four Star Supply, a farm, fuel and feed supplier with a location off Grand Avenue north of downtown Pullman, according to a news release from the Washington Ecology Department. Officials believe a crack in the bottom of a 10,000-gallon tank was the source of the spill of red-dye diesel, a non-taxed fuel used in heavy equipment.

“It is a concern,” said Joye Redfield-Wilder, a spokeswoman for the Ecology Department based in Central Washington. “Any amount of fuel in the river is a concern.”

Four Star drained the faulty tank and initiated cleanup activities, including hiring a Spokane contractor, after the leak was reported, according to the Ecology Department.

Diesel and “sheening,” the rainbow-like appearance of the substance on the top of the water line, was observed 1,000 feet downriver from the source of the spill, according to the Ecology Department. While there’s a transmission pipe from the tanks to the facility where fuel is sold over the Palouse River, officials do not believe there was a leak in the transmission pipe.

Crews are now installing containment “booms” to keep fuel from continuing to flow down the river. It’s also expected that the fuel will continue to leach into the river from the soil near the affected tank, according to a news release.

Redfield-Wilder said the department encourages those with tanks on their property to ensure their integrity. Property owners can recycle any fuel remaining in tanks that are no longer in use, she said.

“Sometimes it’s an old tank they’re not using anymore, and they don’t pay attention,” Redfield-Wilder said.

In 2015, an estimated 1,500 gallons of diesel fuel leaked from a storage tank on a former feed lot near Sunnyside. Oil slicks could be seen in the Yakima River up to 15 miles southeast of the town.

Ecology crews were on scene Tuesday observing cleanup efforts. A phone call requesting comment from Four Star was not immediately returned Tuesday.