The Coos Bay area received over five inches of rainfall from Saturday through Monday. The increased rainfall and saturated ground impacts the sanitary sewer system because of a condition called inflow and infiltration (I/I). I/I occurs when ground water and surface water enter into the sewer system through deficiencies in the pipe. Unfortunately, this is common in ageing infrastructure. Due to the intense rain event, the system that conveys the sanitary sewer from the downtown area to Pump Station #1 (located at SW corner of Birch Ave. and N Front Ave.) was at capacity and surcharged. The increased flows resulted in two sanitary sewer overflows (SSOs) on Monday, February 25, 2019. An SSO is an overflow, spill, or release of wastewater at a non-approved location. The two locations were at the alley north of Golden Avenue between S. 2nd Street and S. Broadway Street and the alley north of Curtis Ave. between S. 4th Street and S 2nd Street. In totalthe SSO continued for approximately seven hours and total of 36,750 gallons escaped the sewer system and entered Coos Bay via the storm drain system. This overflow was reported to Oregon Emergency Response System (OERS) and Oregon Department of Environmental Quality (DEQ). Any questions or observation of sewer escaping out of a manhole please contact the City of Coos Bay Public Works Department at (541) 269-8918 immediately to investigate the situation.
