The leak was first noted by workers at Black Soil Dairy near Granville on March 11, but they didn’t realize that it was flowing into a nearby creek. Instead, they incorrectly believed it was going into a drain that led to manure storage.

The facility has a capacity of about 3,300 cattle in three barns and employs a filtering system that washes manure from the barn floors with shallow streams of water. Sand that is used for animal bedding clogged part of the system and caused the overflow.

“The manure beneath the floor flooded a portion of the barn and flowed outside of the barn through a crack in the wall,” according to a recent DNR administrative order.

An unknown amount of manure leaked from the facility and through underground tiling into Deep Creek and one of its tributaries until March 14, when the dairy’s owner returned from out-of-town travels, saw the leak and stopped it. The owner, Nate Zuiderveen, constructed a basin to catch the manure and plugged two nearby tile intakes.

By that time, evidence of manure contamination of the creek was noted about five miles downstream, and there were dead fish. The true extent of the contamination was unclear because much of the waterways were covered by ice, the DNR order said.

Zuiderveen also hired someone to pump the contaminated water from the tributary.

“They were cooperative, but at the end of the day it’s still a violation of multiple regulations,” said Jennifer Christian, a senior environmental specialist for the DNR who investigated the spill.

Zuiderveen agreed to pay a $10,000 fine and to develop a plan to train his employees to monitor the manure and report problems.

Those who pollute waterways can be held liable for the fish that are killed, but in this case the DNR’s fisheries bureau was unable to estimate the number of dead fish because of the ice.