COEUR d'ALENE - The U.S. Environmental Protection Agency has fined the Idaho Panhandle National Forest $15,000 for failing to report a large anhydrous ammonia spill.

The fine was levied against the agency on April 1 of this year, according to a release issued by the EPA on Thursday.

The 1,600-pound spill occurred Aug. 11, 2013, at the IPNF nursery at 3600 Nursery Road in Coeur d'Alene just off Kathleen Avenue. Jeff Philip, who works in public affairs for EPA Region 10, said the Forest Service was aware of the spill a day after it happened but waited two weeks until Aug. 26 to report the incident.

The Comprehensive Environmental Response, Compensation, and Liability Act, or CERCLA laws, require any person in charge of a facility to immediately notify the EPA's National Response Center as soon as a reportable release of a hazardous substance occurs. Anhydrous ammonia is listed as a hazardous substance with a reportable quantity of 100 pounds or more, according to a consent order issued by the EPA.

Jason Kirchner, a spokesman for the Panhandle National Forest, said a leak in the tree nursery's refrigeration system caused the spill. He said the leak occurred as a result of a power outage that was caused by a lightning storm.

"We knew there was a problem with the refrigeration unit right away," Kirchner said, explaining that his agency called a repair contractor, who said it was "'no big deal.'"

That was until the company came out two weeks later to fix the unit and discovered it was much worse that they expected, Kirchner said.

Anhydrous ammonia is toxic and can be a health hazard, according to the EPA's Integrated Risk Information System.

Effects of inhalation of anhydrous ammonia range from lung irritation to severe respiratory injuries, with possible fatality at higher concentrations. Anhydrous ammonia also is corrosive and can burn the skin and eyes.

On Aug. 12, the EPA said, the Forest Service became aware of the release of anhydrous ammonia at the facility.

"(The Forest Service) failed to immediately notify the NRC of the release, in violation of CERCLA," the consent order stated, adding EPA had the authority to assess a civil penalty of not more than $37,500.

"EPA has taken into account the nature, circumstances, extent, and gravity of the violation and, with respect to (the Forest Service), ability to pay, any prior history of such violations, the degree of culpability, economic benefit or savings (if any) resulting from the violation, and such other matters as justice may require," the order stated. "After considering these factors, EPA has determined and (the Forest Service) agrees that an appropriate penalty to settle this action is $15,000."

The Forest Service agreed to pay the total civil penalty set forth in the consent order within 30 days of the effective date of the Final Order.