Corvallis, OR -

A cleanup is underway in the Marys River in downtown Corvallis where drilling mud from a natural gas pipeline project oozed into the river Aug. 15.

The Gazette-Times reported Tuesday that state biologists found dead invertebrates but few dead fish.

The spill was bentonite, a clay used as a drilling lubricant. It's not generally toxic to humans but can threaten aquatic life.

Plans called for invertebrates and any fish to be netted and removed. Then a contractor is to use a vacuum truck to suction the spill into two 21,000-gallon settling tanks to separate the mud from the water. The bentonite will go to a rock quarry.

Work continues on the NW Natural project, a $17 million line stretching nine miles from a trunk near Albany.