POSTVILLE - Wednesday night, a pump at the Postville wastewater treatment plant was left on, causing wastewater sludge to overflow into Williams Creek on the northeast side of town.
After discovering the discharge about 9 p.m., the wastewater operator stopped the discharge, contacted downstream landowners and built a compost berm to help contain the sludge.
A minimum of 37,500 gallons discharged to the creek. However, two beaver dams contained most of it within 75 yards of the treatment plant. Wednesday night, city staff began pumping sludge from the stream above the dams. They continued pumping this morning and saw live fish above and below the beaver dams.
Williams Creek flows about eight or nine miles before entering the Yellow River in Allamakee County.
The DNR is monitoring cleanup today and will consider appropriate enforcement action.