Grant County officials said a small diesel fuel and oil spill from a sunken dredge barge was contained Sunday.
The Moses Lake Irrigation District's dredge barge was found partially submerged in the Parker Horn tributary on Saturday. The barge held about 600 gallons of diesel and 300 gallons of synthetic oil.
Officials said only a small amount of synthetic oil spilled into the waterway, and most of that was captured with a primary containment boom.
Cleanup efforts started Saturday afternoon.
The Parker Horn ecosystem appears unaffected, officials said.