City of Coos Bay report – It is summertime! That means it’s the time of year for Coos Bay’s Water Quality Team to do maintenance on the wastewater treatment plants. Due to low flows during this season, the Team can take down basins and perform routine maintenance and inspection. This week the Team took down one of the two basins at Plant Two located at 490 Fulton Avenue. These basins are where the main biological treatment process occurs. Water Quality Team Summer Cleaning – At the bottom of the basins are diffusers (these diffusers will inject micro bubbles of air into the waste which provides oxygen to the good microbes that eat the sewage. After the aeration cycle, the air is turned off and the solids are allowed to settle to the bottom of the tank. The clean water is then slowly decanted off the top of the basin into a large storage chamber, the equalization basin. After decanting, the air cycle starts again as fresh wastewater is mixed with the colony of good microbes that remain in the basin. This year, members from the Water Quality Team including Treatment and Maintenance Operators entered the basin and cleaned out the remaining solids. They also inspected and cleaned each diffuser to ensure that it is functioning properly. This annual maintenance is vital for preventative maintenance and ensuring that the equipment is properly maintained.