The reserve is located in the northeast part of Saskatchewan. (CBC)

A small First Nations community in northern Saskatchewan has admitted wrongdoing after more than 5,000 litres of diesel fuel from a storage tank spilled and contaminated a nearby lake nearly three years ago.

The Hatchet Lake Denesuline First Nation expects to pay $50,000 in fines after pleading guilty in court to environment-related charges in La Ronge, Sask., on Monday.

The band was charged in 2006 after the fuel ran off into Welcome Bay, near Wollaston Lake, about 550 kilometres north of Prince Albert.

Originally, a 12-year-old boy was accused of causing the spill after he opened the valve on the fuel tank, but a criminal charge against him was stayed by the Crown.

Prosecutors said the band should be held responsible because it didn't do enough to secure the tank from being tampered with. The fuel spill cost $680,000 to clean up and now band officials in the remote community are worried the federal government may come looking for payment, band lawyer Jack Hillson said.

Hillson said that money would come straight out of the community's budget for programs. Fewer than 1,000 people live there.

"Any fine that they are forced to pay comes right out of the band budget, right out of monies that would be available for education, social development … everything that the band normally does and the services they offer to members," Hillson said.

Court location triggers guilty plea: councillor

In November 2008, the band lodged public complaints about where the court case would be heard.

On Monday, band councillor Ed Benoanie said the band wouldn't have pleaded guilty if the Crown had agreed to hold a trial in the community. He said many witnesses didn't want to travel the 460 kilometres south to appear in court in La Ronge.

But Crown Attorney Inez Cardinal said that wasn't practical, and a judge agreed.

"There may be issues with getting into the community, depending on the time of year. And as well, if you have a number of witnesses — which we could have had for the trial — there's accommodation issues and transportation issues," Cardinal said.

A sentencing hearing will be held in December to determine the exact amount the band must pay.