WEEDSPORT - Plans for an improved sewer treatment plant in Weedsport are moving along.
At a special meeting Tuesday, village board members listened to and discussed various methods to aerate village waste water as they prepared to upgrade their treatment plant.
Eric A. Pond, Sr. managing engineer for Barton & Logidice, P.C., presented the board with a packet explaining a variety of design options and parameters to guide them through the design phase of aeration.
The aeration system is the heart of the activated sludge system and it accounts for the majority of the overall plant consumption.
After comparing diffused air (either fine or coarse bubble), jet aeration, and various other configurations for a three-tank Sequencing Batch Reactor (SBR), the board moved to proceed as planned with the diffused air model.
“We need to take the manufacturers figures with a grain of salt,” Pond advised the board. He suggested a realistic approach rather than the “pie-in-the sky” figures provided by manufacturerers reflecting optimum conditions.
Factors the board considered were efficiency, maintenance, long-term use, and cost savings.
Two factors affecting efficiency were Alpha value and oxygen transfer efficiency. Alpha value is a comparison of oxygen in crystal-clear water with air mixed into wastewater by aeration. It is expressed as a decimal (or percent) with .85 being excellent and .72 not bad, for example. The Alpha figure varies depending on the configuration of the equipment doing the aeration and even with atmospheric pressure.
“The only way to know the true Alpha figure is to test it after you build it,” Pond said, noting that larger municipalities sometimes build a prototype before actually deciding on a system.
Oxygen transfer efficiency refers to how long oxygen bubbles stay in the mixture and how big they are.
“The longer you keep bubbles in the mix, the better,” Pond said. “The finer the bubble, the longer it will stay.”
The next step in the design phase will be specific figures comparing costs and then putting the plan out to bid.
Pond said it would be a long process, and he didn't expect the bid process to begin until winter.
Eric A. Pond, Sr. managing engineer for Barton & Logidice, P.C., presented the board with a packet explaining a variety of design options and parameters to guide them through the design phase of aeration.
The aeration system is the heart of the activated sludge system and it accounts for the majority of the overall plant consumption.
After comparing diffused air (either fine or coarse bubble), jet aeration, and various other configurations for a three-tank Sequencing Batch Reactor (SBR), the board moved to proceed as planned with the diffused air model.
“We need to take the manufacturers figures with a grain of salt,” Pond advised the board. He suggested a realistic approach rather than the “pie-in-the sky” figures provided by manufacturerers reflecting optimum conditions.
Factors the board considered were efficiency, maintenance, long-term use, and cost savings.
Two factors affecting efficiency were Alpha value and oxygen transfer efficiency. Alpha value is a comparison of oxygen in crystal-clear water with air mixed into wastewater by aeration. It is expressed as a decimal (or percent) with .85 being excellent and .72 not bad, for example. The Alpha figure varies depending on the configuration of the equipment doing the aeration and even with atmospheric pressure.
“The only way to know the true Alpha figure is to test it after you build it,” Pond said, noting that larger municipalities sometimes build a prototype before actually deciding on a system.
Oxygen transfer efficiency refers to how long oxygen bubbles stay in the mixture and how big they are.
“The longer you keep bubbles in the mix, the better,” Pond said. “The finer the bubble, the longer it will stay.”
The next step in the design phase will be specific figures comparing costs and then putting the plan out to bid.
Pond said it would be a long process, and he didn't expect the bid process to begin until winter.
