Bedford Township Wastewater Treatment Plants Gets Updates, Improvements, Expansion to Services
MONROE COUNTY - For half a century, the Bedford Township Wastewater Treatment Plant (WWTP) has been turning wastewater from Monroe County businesses and homes into clean water for its customers. The plant, located on LaVoy Road, is large enough to process more than 13 million gallons of wastewater per day and is operated by the Monroe County Drain Commissioner (MCDC) with funding supplied by users in Bedford Township.
Built in the early 1970s, much of the treatment plant has been maintained and upgraded in the past five decades. Some of the original equipment and processes, however, have continued to be in operation since the plant’s opening day.
“We had a few items of the original equipment from when the plant was constructed,” David Thompson, the Monroe County Drain Commissioner, said. “Throughout the years, we’ve had excellent staff at the wastewater treatment plant, and they have maintained everything so well. We were able to get quite a bit of life past the expected life span because things were so well taken care of.”
Spicer Group has been assisting Monroe County and the Bedford Township Wastewater Treatment Plant facility with improvements, maintenance, and equipment replacement projects for ten years. In 2015, Spicer Group completed an asset management plan for the wastewater collection system and WWTP which identified numerous capital improvements that needed to be addressed for the plant to continue providing its service.
After completing the asset management plan, Monroe County was approved for a $17 million State of Michigan Revolving Fund loan to complete an overall comprehensive project that included 25 system additions, replacements, and improvements at the WWTP and three sanitary sewer pump stations.
At the WWTP, these comprehensive improvement projects took place within seven buildings, updated 16 processes, and added eight new processes. The improvements extended the useful life of the plant by another 50-100 years, ensuring safe and efficient infrastructure for providing a public service.
The improvements included the installation of completely new processes such as an ultraviolet (UV) disinfection, a final effluent water system, and a sludge dewatering press. Improvements were also made to existing plant processes such as the secondary clarifier brush system, reconfiguration of the plant drain, installation of energy-saving variable frequency drives (VFDs) on new and existing pumps, and isolating slide gates in the influent wet well channels. Equipment at the end of its useful life was also replaced, such as the primary sludge pumps, digester gas equipment, and heat exchangers.
Ultraviolet Disinfection
Architectural improvements made to the plant included remodeling and adding to the administration building, a locker room addition, and blower sound attenuation.
The new ultraviolet disinfection installed replaced the plant’s former process of injecting chlorine gas into the effluent as a final step to creating clean water. The UV disinfectant process uses nothing but ultraviolet lamps that are submerged in the effluent. This UV light instantaneously neutralizes any microorganisms in the water.
“UV has been successfully used to disinfect drinking water and wastewater for many years,” Spicer Group Principal Phil Westmoreland, P.E., said. “The UV process eliminates the need for WWTP staff to handle dangerous chlorine gas, resulting in a safer work environment. It also eliminates potentially harmful disinfection byproducts, reducing the environmental impact.”
Thompson said he was “very excited” about replacing the chlorine disinfection process at the plant.
“We are moving away from very dangerous chlorine gas cylinders on-site and moving to a more environmentally friendly method for disinfection,” he said. “I think this is a great step towards the future.”
Another new process installed was the sludge dewatering press system. This press reduces the liquid in the waste by using compression pressure on the liquid, turning it into a dry dirt composition rather than the liquid sludge the plant previously produced.
The resulting solids “cake” is stored on a 10,000 square foot concrete pad where it continues to dewater until it is time to remove it and be hauled away.
“When all is said and done, the plant staff will not be maintaining and repairing old equipment. This will allow them to focus on other aspects of the collection system and plant and enable them to use their time more efficiently,” Spicer Group Project Manager Tracy Anderson, P.E. said.
Once the design was complete, bidding was advertised and awarded to Heaney General Contracting, Inc., based in Ypsilanti, as the general construction contractor. The improvement projects were set on a schedule that would allow the contractor’s construction crews to work around the plant’s operation, as the plant had to remain in operation while construction was happening.
Sludge Dewatering Press System
The improvements made and equipment selected to replace systems or add to the plant and wastewater infrastructure with this project lessened the impact the plant has on the environment by improving the overall energy efficiency of the plant, use of less environmentally harmful processes within the plant, and reducing the amount of waste product the plant produces.
Wherever possible, energy-efficient equipment was installed when replacing equipment or installing new equipment within the wastewater treatment plant and at the improved pump stations.
With the replacement of aged, inefficient equipment and systems, the plant will realize enough energy savings to counter the additional energy use from the UV disinfection. Chemical costs will be reduced by 10% per year, and the water savings from the use of the final effluent water will reduce potable water usage from South County Water System.
Spicer Group was responsible for all the design, survey, bidding assistance, construction administration, inspection, and coordination on this project.