Sanitary Sewer Overflow, Oct. 22

City of Coos Bay release – Wednesday evening at around 4:28 pm, the City of Coos Bay experienced a sanitary sewer overflow (SSO) at a sewer manhole in the intersection of S 3rd street and Anderson Avenue. The overflow was caused by a grease blockage located in the downstream sewer system. The City’s Water Quality Collections crew removed the blockage within one hour of being notified but the event caused approximately 180 gallons to spill over to the storm drain system and discharge into the Bay. The SSO was reported to the Department of Environmental Quality and Oregon Emergency Response System. Fats, oil and grease (FOG) can have negative impacts on wastewater collection and treatment systems. A large majority of wastewater collection system SSOs can be traced to FOG. Two types of FOG pollutants are common to wastewater systems. Petroleum-based oil and grease (non-polar concentrations) occur at businesses using oil and grease and can usually be identified and regulated by municipalities through local limits. The other type of FOG is animal and vegetable-based oil and grease (polar concentrations) and are more difficult to identify the source due to the large number of residential homes that a collection system serves. Eliminating the introduction of FOG to the sanitary sewer system can reduce the number of blockages and ultimately reduce the potential for future sanitary sewer overflows. Any questions can be directed to the City of Coos Bay Public Works Department at (541) 269-1181 EXT 2500.