ST. LOUIS (AP) — Cleanup is underway after an estimated 90,000 gallons of sewage spilled into a St. Louis waterway.

Workers for the Metropolitan St. Louis Sewer District on Monday discovered a blocked sewer that allowed sewage to spill into the River Des Peres.

Cleanup is expected to take up to three days. MSD officials are urging the public to avoid contact with the River Des Peres, but to wash thoroughly with soap if contact occurs.