City of Coos Bay release, Aug. 29, Summary: It was discovered that the wastewater treatment plant located at 680 Ivy Avenue experienced high fecal coliform bacteria counts in the sample that was taken yesterday (the test takes 24 hours to yield results). Unfortunately, the cause of the high fecal count is due to an operator error by the City’s wastewater contractor. The error has been corrected and the operators are increasing the dosage of disinfection chemicals until acceptable Fecal Coliform counts are observed. Detailed Report: The wastewater treatment plant located at 680 Ivy Avenue experienced high fecal coliform bacteria counts in the sample that was taken yesterday (the test takes 24 hours to yield results). Fecal Coliform are used as indicator organisms to test the effectiveness of effluent disinfection in a wastewater treatment plant. While these organisms are generally harmless to us, they do live under the same conditions that human pathogens live. Since we cannot test for every pathogen in the effluent, we test for easily detectable indicator organisms. The assumption is that if we kill the indicator organisms then we most likely kill the pathogens during effluent disinfection. The Plant has to meet effluent water quality limits that are identified in a permit that is issued to the City by the Oregon Department of Environmental Quality (DEQ). The Plant does not have daily fecal limits (only monthly) but at this time it is believed that this will result in a permit exceedance. The cause of the permit exceedance was due to an operational error. The City contracts out their operation maintenance of their wastewater system to a private contractor. During the summer months, it is common to take equipment down for maintenance. In this case, one of the aeration basins was taken out of service. An aeration basin is where air is introduced to the process and mixing occurs (both are vital elements of wastewater process). Unfortunately, the operators did not readjust the air level when the basin was put back in service and it resulted in a high fecal count. The operators have corrected their operations protocol and has increased dosage of disinfection chemicals. The City reported this issue to the Oregon Emergency Response System (OERS). Any questions can be directed to the City of Coos Bay Public Works Department at (541) 269-8918.
