Wastewater System to See Long Overdue Updates, Rate Increases
Sewer infrastructure is underground so nobody thinks about it and yet, when it breaks down everyone knows and it can no longer be ignored. Fortunately, operators Tim Kriezov and Tony Smith keep it on their minds all the time. And they aren’t alone. A number of years ago, Portland contracted the operations of the waste water treatment plan to Fleis & VandenBrink Operations (F&V) bringing on board Ken Dey bringing a wealth of experience operating waster water treatment plants both large and small to the task. That mindfulness has led to plans for major, and long neglected, upgrades and updates to the city sewer system starting next year.
While many Portlanders are only now becoming aware of this need, the process actually began nearly a decade ago in 2013 when the city applied for a Stormwater Asset Management and Wastewater grant form the State of Michigan. That more than $700,000 grant funded a systematic assessment of every inch of the sewer system. That review found a number of repairs needed urgently to keep the system operating and improvements to allow capacity for continued development in the future.
The survey found that several areas of sewer line are in need of complete replacement including on Bristie, Water, Center, West, and Church Streets as well as part of Grand River Ave. The sewer line running under the Grand River is also to be replaced. While these areas will see larger scale construction which will involve digging under and possibly reconstructing roads or sections of road, many other sections of sewer and manhole access points will see repairs and lining of the pipes to extend their life. These areas are near Water and Grant Streets as well as the connections to the Grand River crossing line.
The department also maintains three lift stations around the city that pump sewage from areas of lower elevation to where it will flow downhill to the treatment plant. Pumps, valves, and electrical controls will be overhauled at all three stations and, and upgrades made at the canal street station to improve reliability in case of power outage. On Riverside Drive, the lift station building will also be replaced. The Rindelhaven lift station which provides sewer service to the busy rest area on I-96 west, will see improvements to decrease the accumulation of “rags” clogging the system.
According to sewer operator, Tony Smith, the build up of “flushable” wipes, feminine hygiene products, diapers and other items is a major cause of ongoing problems with the system. He urges that you not flush anything down the toilet except for waste and toilet paper. He emphasized that while a number of products claim to be “flushable” that they are not actually safe for sewers and cause serious problems. Through this project the upgrades will include pumps and fittings that F&V engineers says will help minimize clogs. However, Smith says that cleaning out clogged manholes is still a major part of the job.
A major change will see the secondary treatment tanks transitioned from its current system where bacteria break down waste by being circulated between a maze of connected tanks to what is called a moving bed biofilm reactor. This system will utilize the existing concrete tanks but also incorporate honeycomb shaped plastic beads. These beads will float in the waste tanks and create space for bacteria to live and grow as they clean the water of waste. This upgrade will increase the efficiency and reliability of the process and make it capable of expanding the capacity to treat more wastewater as needed in the future.
Chemical storage systems are also being upgraded as the department switches from its current ferrous chloride to a newer ferric chloride system. This chemical is added to help remove excess phosphates from the wastewater. This change will make the system more efficient and require less chemical input while keeping phosphate, which can cause dangerous algae blooms out of the discharged water. These chemicals will be stored in a new multipurpose garage where air handlers and service equipment will also be housed.
Perhaps the largest update is to the solids handling and storage. Currently, the plant utilizes a process called anaerobic digestion to break down solid waste. These large tanks are buried in earthen berms to insulate them as the bacteria fermenting and breaking down the waste require a toasty temperature in the nineties year round. In the winter, that means burning natural gas to heat the tanks. The new system will see these tanks transitioned to aerobic bacteria that do not require high temperatures thus saving on energy costs and cutting the carbon footprint of the plant. Currently, these digesters are emptied several times a year and the treated biosolids injected in farm fields as fertilizer. Under the new system biosolids will be stored in a new above ground tank which will allow more flexibility in when fertilizing occurs and the logistics involved.
In total the updates are projected to cost $10 million dollars which the city has borrowed as bonds. Because this project has been in the works for several years they were able to secure rock bottom interest rates of 2.125% which is unheard of today. In addition the project qualified for a $1.5 million dollar principal forgiveness program through the State of Michigan The issuing of bonds is tied to sewer rate increase of 29% in 2022 and a further 25% rate rise in 2023. For most residential consumers, sewer rates are currently $21.36 for every 1000 gallons which is determined by water meter use. Under the new rates, that would rise to $27.55 for every 1000 gallons. While this change may sound like a lot, the city says that these rate changes will bring sewer rates up in line with what is charged in most similar sized cities across the state. At the end of the day, according to city manager, Tutt Gorman, “it's a public health issue…you’ve got to take care of the things your supposed to do to maintain it.”
PHOTOS: Map Courtesy of F&V and the City of Portland. All others by the author.
Editors note: The original posting of this piece stated that the bond interest rate would be 1.8%. That rate will actually be 2.125%. We apologize for this error.