College of Engineering Unit:
The City of Monroe is located about 18 miles south of Corvallis, OR. Alongside the city lies the Long Tom River, which the City of Monroe plans to centralize in future developments by developing along the riverside section of the city. Current population numbers are below 1000 and are expected to continue to increase. The city has 650 residents and the population would increase at an average annual growth rate of 0.73%. Additionally, a new brew pub has recently opened in the city. As the population increases, the water demand within the city is expected to increase as well, leading the City of Monroe to focus largely on water supply and water treatment improvements.
For the past five years, the City of Monroe’s wastewater treatment plant (WWTP) has exceeded the allowable BOD load, set by the National Pollutant Discharge Elimination System (NPDES) permit, into the Long Tom River. As the new brew pub opened, a commercial source of wastewater has been introduced to the city, increasing the total flow and BOD mass loading sent to the local WWTP.
The current system consists of three facultative ponds and a chlorine contact chamber. The facultative ponds possess a total surface area of 10 acres. Reports are to be analyzed for information regarding the current treatment system, with the goal of ultimately improving upon the current treatment system to provide effluent TSS and BOD loads that are within the limits specified in the NPDES permit. Public law 117-58 can make the project obtain additional funding. Additionally, nitrification will be utilized in order to accommodate for the possible inclusion of limitations on nitrogen loads into the Long Tom River in future NPDES permits.