This Monday, November 26, 2018, the influent gate to the new Wastewater Treatment Plant No 2 was opened. On Tuesday, the new plant was discharging treated and disinfected sewage into the Bay. The Plant has to meet effluent water quality limits that are issued to the City by the Oregon Department of Environmental Quality (DEQ). Daily testing has occurred since the plant has been discharging effluent. For the past two days, samples have come back within normal permit parameters. However, this morning it was discovered that there are high counts in the fecal coliform bacteria sample that was taken yesterday (the test takes 24 hours to yield results). When treating wastewater, the heavier solids separate/settle so that the microorganisms can break them down. There is always a fine balance between the number of microorganisms to the volume of solids. Too much of each can cause a plant to become unstable. For the first two days, the new Plant initially experienced very good separation of solids, but the balance of raw sewage to micro-organisms was not adequate as flow rates increased with the recent rains and waste from the existing plant was transferred to the new plant. This allowed for solids to flow through the Ultra Violet (UV) disinfection system and thus prevented the light from effectively disinfecting bacteria to acceptable permit levels. Currently the operations crews are supplementing the Plant with more seed sludge that is full of microorganisms to help break down the solids and the UV system has been temporarily increased to provide the maximum UV dosage recommended by the manufacturer. Additional testing will be conducted on a daily basis until this issue is resolved. It is anticipated that with these steps the plant will equalize and thus the treatment process will improve. In starting up plants, it is anticipated that there might be complications. Due to the potential of endangering human health and the environment this situation was reported to DEQ and the Oregon Emergency Response System. Furthermore, signs have been posted at the beach access points, near the Plant’s outfall, warning people of potential high bacteria limits. Prior to harvesting shellfish, it is recommended that you check with the Department of Agriculture and/or Coos County Public Health for any updates. For any additional information please contact Public Works at 541-269-8918.
