IA DNR: Duncombe Ammonia Leak Contained on Site at Koch Plant

The DNR confirmed Wednesday that the plant was not discharging to the river and that the company was using a number of methods to prevent any discharge.

Four semi tankers Tuesday afternoon to continuously haul wastewater from their treatment system to the Fort Dodge wastewater treatment plant for disposal. As of 8:00 a.m. Wednesday, they had hauled 24 tanker loads.

The company is collecting wastewater samples from each tanker load and hourly throughout the system to track ammonia levels in the wastewater ponds.

In addition, the plant has gone into water conservation mode, so that they can continue to make product, but the tankers can haul all the wastewater produced to Fort Dodge. Other efforts to reduce ammonia levels in the treatment ponds include recirculating and aerating wastewater between several ponds on the plant grounds.

Plant officials shut down the wastewater discharge to the Des Moines River Tuesday afternoon after repair workers discovered that an estimated 18,000 pounds of ammonia had reached their treatment ponds and elevated the ammonia levels in the ponds.

The DNR will continue to monitor the situation and consider appropriate enforcement action.

MEDIA CONTACT: Trent Lambert at (641) 425-6075 or (641) 424-4073.

Ammonia Leak at Koch Nitrogen Plant in Webster County Now Rerouted
Posted: April 15, 2008

DUNCOMBE – The release of a relatively small amount of anhydrous ammonia at a chemical plant in Duncombe early Tuesday morning turned out to be much larger than originally estimated.

Technicians at the Koch Nitrogen plant discovered the release was about 18,000 pounds, not 300 pounds, when they began to make repairs. Most of the ammonia was in liquid form and had leaked under plant equipment, flowing into the plant’s wastewater system.

Normally it would be treated before discharge into the Des Moines River. However, ammonia concentrations in the two wastewater ponds became elevated to 28 and 14 parts per million, exceeding the plant’s maximum discharge limit of 12 parts per million.

Wastewater from the ponds was being discharged to the Des Moines River, but plant officials stopped the discharge Tuesday afternoon after discussing the situation with the DNR.

“Although the level of ammonia in the wastewater was just slightly over their permit limits, we explored a number of alternatives to avoid a discharge,” said Glenn Carper, an environmental specialist in the Mason City DNR office.

Carper said the plant shut down the pumps and is now hauling some of the wastewater about seven miles to Fort Dodge for treatment. Some will be pumped to another retention pond and recirculated in the plant. The rest of the wastewater will be pumped back and forth between holding ponds to aerate it and break the ammonia down.

“This is a case where discussing the options with us gave the plant manager some alternatives they might not have considered,” Carper said. “That’s a win-win situation for the plant and the river.”

Downstream water treatment plants have been notified.

The DNR will continue to investigate on Wednesday and consider appropriate enforcement action.

MEDIA CONTACT: Glenn Carper at (641) 425-0512 or (641) 424-4073