April 15, 2019 Work Session Minutes
BUCHANAN CITY COMMISSION SPECIAL MEETING MINUTES
Review of Oxidation Ditch for the Wastewater Treatment Plant
Monday, April 15, 2019
A Special Meeting of the City Commission for the City of Buchanan was scheduled at City Hall, 302 N. Redbud Trail, Buchanan, Michigan Monday, April 15, 2019 at 6:00 p.m. The Mayor called the meeting to order at 6:00 p.m. The Mayor led the Pledge of Allegiance.
Members present: Mayor Moore, Commissioners Toerne, Weedon, and Denison
Members absent: Commissioner Downey
Staff present: City Manager Bill Marx, Waste Water Treatment Plant Operator Bill Housand, and City Clerk Brenda Hess
Guests/Visitors present: Mark Hurley, Engineer Gosling-Cuzubak Construction
Manager Marx introduced Mark Hurley and provided a review of session purpose.
Mr. Hurley showed an animated overview of the new oxidation ditch in relationship to the current plant. Waste comes into the headworks in the future the headworks will pump waste to the top of the hill to the new ditch. Peak flow limits will be 4,000,000 gallons per day even though it will most likely never be required of the system.
The screens remove all solid items that should not flow into the plant. The grit chamber removes the heavier non-digestible materials, including grit (sand) which ruins equipment. The classifier sorts it out and this material is currently removed by wheelbarrow.
Influent pumps will send the waste to the new ditch, instead of the present reactor. The current reactors must maintain high levels of bugs (digesters) to keep down odors. The new ditch will be able to house more waste materials and digesters for a longer period of time. The current plant has blowers that inject air into the water, but it’s inefficient. The ditch will be much more efficient. The impeller will keep the waste moving exposing it to the air and the bugs. The process becomes much more stable and reduces the demand on the system.
Bill Housand commented that this will make it much easier to run and maintain our plant. The footprint of the new plant will be larger to accommodate a higher number of bugs and it will be shallower (only 10 to 15 feet deep). Most of the ditch will be under the ground, keeping it warmer (which improves efficiency and cost), while also making it look more appealing to those passing by on River Street. The covers on the ditch will reduce odors, noise and keep out water from rain/snow adding to efficiency and stability in the treatment process. It will feature a berm with fencing and landscaping. Security cameras will be installed for monitoring of dumping at the receiving station.
The estimated savings in maintenance costs are approximately $50,000 each year for the new plant. After treatment in the ditch, the water travels for UV disinfection before it returns to the environment. The new plant will only need to use one clarifier. Clarifiers use intense UV lights to sanitize the water after treatment. The bulbs in the new plant for will respond to changes in need for intensity and will save money in the lives of the bulbs as well as in the consumption of energy. The bulbs are also self-cleaning which reduces maintenance costs and operator time. The new bulbs are also better warrantied which will save money as they need to be replaced and are manufactured in the United States in South Carolina. UV lights disrupt the DNA of the microbes that would contaminate the water in the environment making it safe for release into the watershed.
Our current solid waste digester is very inefficient. There will no longer be a need for solid waste “beds” which are very labor intensive in the current plant. The sludge pump in the new plant will inject solid waste with a polymer which will remove more water from the solid waste which is recycled. The remaining odorless treated sludge emerges from the system in a dry cake like consistency, then it is sent to a dumpster and taken to the landfill. Currently solid wastes are treated in beds. The beds are manually filled with solid waste and spread out to dry. The beds are also manually emptied. Presently solids take a lot of time to dry before going to the landfill. The current beds are very weather dependent and easily flood in heavier rains. Because the new plant will not need the labor-intensive solid waste drying beds, it will free up operator time.
The lab will be new, and the old equipment will be utilized as much as possible. Buchanan helps Baroda and Galien with sample testing and additionally runs panels on wastewater from the landfill. The SCADA control panel will be located in the lab along with other controls. Because multiple waste handling steps will be eliminated with the new plant, there will be less need for multiple tests.
The transfer of service from the old plant to the new plant will utilize tanker trucks moving waste from the old plant to the new plant to start the new treatment process. The new plant will be tested with water first to check pressures and operations of the equipment. Time will be needed to get the digestive bugs working. During the service transfer process from the old to the new plant, all waste will be treated, and none will be released in violation of our permit protecting the environment.
Certification for construction will be stamped by the construction company and the treatment will be certified by Bill Housand. The DEQ will approve preliminary plans, and will receive prints (in July) with updates throughout the process. The construction process will take 16 months and should be completed in 2021.
It was noted that there are significant mechanical issues at the current plant which will still need to be maintained until the new plant is complete and operational. The current plant is at the very end of its life and there will still be significant expenses to keep it running. Some components in the current plant are from 1930s.
The lifespan of the new plant (structural) is 100 years. The mechanicals will vary depending upon the component and its maintenance schedule.
Replacement of lead water service lines was briefly discussed regarding cost and personnel being shared between the water and wastewater departments. The new plant will require less labor and it is possible to share an operator with the water department to possibly work on the lead service line replacement project.
Commission questions were answered throughout the presentation.
Being no further discussion, Toerne moved, seconded by Denison to adjourn the meeting at 7:15 p.m. Voice vote carried unanimously.
Brenda J. Hess Patricia Moore, Mayor