SNOHOMISH, Wash. - Engineers have determined what led to the failure of a manure-filled storage lagoon in Snohomish County in April.
The U.S. Dept. of Agriculture says the storage pond had been mistakenly built over an old wood, field drain. The cedar box added pressure on the waste pond, which was filled to capacity and burst open.
It's believed approximately 27 million gallons of diluted dairy cow manure spilled onto farmland when the pond ruptured.