Recent rainfall combined with saturated ground conditions resulted in the City of Sweet Home overflowing diluted raw sewage into Ames Creek, which flows into the South Santiam River. The influent pump station structure overflowed plant capacity at approximately 5:24 p.m. on Sunday, Feb. 23, and concluded at 10:44 p.m. on the same day.
According to a press release from the city, when the ground becomes saturated, groundwater enters the sanitary sewer system through cracks and holes in the pipes, in addition to footing drains, and other sources of extraneous water from private property. When this occurs, the ability of the sewer system to transport sewerage to the wastewater treatment plant is exceeded and the system becomes surcharged. When these conditions become severe enough, the level within the WWTP’s influent pump station surcharges, then overflows to Ames Creek.
Signs were posted warning people to avoid contact with the water in Ames Creek and South Santiam River due to potentially higher levels of bacteria. The signs were removed when the overflow concluded and bacteria levels were determined to be normal.