The City of Otsego maintains two municipal Wastewater Treatment Facilities. The East Facility was established in 2000 and the West Facility 2004.
Otsego West Wastewater Treatment Facility (WWTF)
The Otsego West Wastewater Treatment Facility initiated service in 2005. The site uses a combination of biology and chemistry to naturally clean the municipal waste stream. Wastewater is collected from the surrounding sanitary system and pumped to the facility by two large lift stations delivering influent flow to a pretreatment building. The equipment inside this building removes screenings and grit to prepare the liquid stream for biological treatment. The majority of treatment occurs in the aeration zones. Microorganisms are mixed with the provided wastewater and break down the organics as it is the life source that supports their wellbeing. After aerobic mixing occurs, a settling clariﬁer will ﬁlter water from the microorganisms. The remaining microorganisms are directed back to treat more wastewater and cleaned water ﬂows to a disinfection process using ultraviolet light. The ﬁnished clean water ﬂows into the Otsego Creek and soon thereafter the Mississippi River. The West Wastewater Treatment Facility can process an average of 600,000 gallons per day and is nearing its designed capacity. To support community growth and advanced water quality standards a facility expansion is occurring and will provide treatment of 1,400,000 gallons per day. The upgrades will incorporate pretreatment improvements, membrane technology with biological nutrient removal, and cascade aeration for effluent polishing.
Otsego East Wastewater Treatment Facility
The City of Otsego's East Wastewater Treatment Facility began operations in 2000 and has grown with the community adding capacity and treatment technology improvements. The Facility is a Class A Major Facility with a designed flow of 900,000 gallons per day and current flows nearing 500,000 gallons per day. The Facility uses a Conventional Activated Solids process with extended aeration to accomplish Biological Nutrient Removal (BNR) meeting permitted regulatory requirements.
Wastewater is collected from the surrounding sanitary system and pumped to the facilities pretreatment building by three lift stations. Grit and screenings are removed preparing influent flow for biological treatment. Microorganisms use the fresh wastewater as their food source, mixed and allot time to stabilize the wastewater within the aeration basin. A clarifier is used to settle out those microorganisms and direct them back to the aeration basin and the clean water flows to disinfection prior to existing to the Crow River.
In 2022 a site improvement was completed to incorporate solids processing to meet the highest quality biosolids designation. The minimized building footprint and compact process serve both the East and West Wastewater facilities' solids treatment.
The City of Otsego is now meeting Class A exceptional quality biosolids! This product is a semi-solid material meeting the most stringent pollutant, pathogen and vector attraction reduction requirements under EPA regulation. The material is processed within the Biosolids Building thickened using a centrifuge and pasteurized using lime resulting in an outstanding fertilizer resource. The site is currently processing near 35 tons of material.
Don't Flush Your Disposable Wipes
Disposable wipes - used for changing diapers, personal hygiene, housecleaning, and more cause major problems when flushed down toilets. Because they don't break down the way toilet paper does, these wipes clog homeowner and municipal sewer pipes, put stress on community wastewater collection and treatment equipment, and cause cities to spend thousands on premature equipment repair and replacement. These wipes snag on any imperfection in sewer pipes, catch passing debris and grease, and create a "ball" that will grow to plug the pipe. They also get drawn into sewer-line and wastewater treatment facility pumps and clog and damage them. Municipalities must manually clear out pumps or remove clogs.
Sanitary Sewer Cleaning
The City of Otsego has 67 miles of sanitary sewer pipeline. Most of the lines are in the street and some are through utility easements. The City cleans approximately 20% of the system on an annual basis. Lines requiring a higher level of maintenance are cleaned more frequently. This routine maintenance helps to prevent blockages and backups.
Sanitary sewer lines are cleaned using high-performance sewer cleaning equipment. A cleaning nozzle is sent upstream from one manhole to the next using water pressure then pulled downstream using water jets to scour the interior of the sanitary pipe. Any debris in the pipe is pulled back with the water and removed using the vacuum portion of the cleaning truck.
During the cleaning process, air occasionally can vent into a home causing water in the toilet bowl to bubble and occasionally splash outside of the bowl. If during the process sewer odor is detected the traps in your home should be refilled. These effects may occur during use of higher pressure needs when cleaning lines that have a steep slope, a plugged roof vent or other various home waste and ventilation intricacies. As crews are servicing the area, please close toilet lids.