Jim Butler, Professional Engineer and Project Engineer for the Board of Public Utilities

Sue Jones introduced our speaker, Jim Butler, Professional Engineer and Project Engineer for the Board of Public Utilities who spoke to the club members about the Jamestown Wastewater Treatment Plant.

 

 The City of Jamestown's Wastewater Treatment Plant is located on the Quaint Road in Falconer and is rated to process 7,000,000 gallons of wastewater for 40,000 customers daily.  One hundred forty miles of sewer main varying from eight inches to 60 inches in diameter, collect wastewater from approximately 40,000 users and transport it to the BPU's Wastewater Treatment Plant on Quaint Road in Falconer, NY.  By the time your waste reaches this point, it is not recognized as the waste you ground up in your garbage disposal or flushed down your toilet. The action of the waste being washed through the mains breaks it up into tiny particles which are suspended in the water.  One of two mechanically operated bar screens remove large objects (greater than one-quarter inch) and debris which may plug downstream piping and equipment.

Some of the items recovered from the bar screen are toys - obviously many children's toys, small amounts of money every once in a while and often false teeth. Sometimes they are able to locate lost items, but most times they are not.

 

Primary clarifiers remove coarse solids by settling and remove oils, grease and floating solids by skimming. Sludge that settles to the bottom is removed and pumped to thickeners for further treatment. A skimming mechanism removes floating material, which is transferred to a container for trucking to the landfill. After passing through the clarifiers, the wastewater enters the trickling filter process. Wastewater is pumped underground beneath two trickling filters and pumped up through a central 18 foot rotating column. The spray arms extend from the center column.  The wastewater is pumped from the column into the arms and sprayed or “trickled” over the top of thousands of plastic honeycomb-like media. The pile of the media is 16 feet high, surrounded by a large circular wall. Water pressure moves the arms without the need for electricity, causing them to rotate continuously, spraying wastewater over the media pile.

As the water trickles all the way down through the plastic media, natural-occurring bacteria which have attached themselves to the plastic media, eat the organic materials left in the wastewater. Once the wastewater gets to the bottom of the trickling filter, it is pumped up the column again and the process is repeated approximately 3-4 times, ridding it of organic materials. From the trickling filters, the water flows underground to more clarifiers for more settling out of particles.  The flow then proceeds through four gravity rapid sand filters (only used May through October). Each filter consists of an eight-inch sand bed.

The sand bed retains solid particles and as the sand filter reaches its capacity, a traveling bridge moves along the filter and vacuums the solid particles away from the sand.  All of these processes remove many of the microorganisms from the water, however some may remain, and they may be disease-causing. These remaining pathogens are killed by exposure to chlorine in the chlorine contact tank.  From the chlorine contact tank, the now disinfected water flows by gravity through a 48-inch effluent line to the Conewango Creek.

 

Now that the liquid portion of wastewater has been treated the solids remain. Sludge solids from the primary and secondary clarifiers are pumped to the sludge thickeners.  The thickeners reduce sludge volume through settling and decanting.  Thickened sludge is fed to anaerobic digestion tanks for stabilization. Anaerobic digestion is a biological decomposition process that occurs in closed, heated, mixed tanks. This process reduces the volume of sludge, creates methane gas and renders the material more conducive to dewatering.

 

Methane generated in the anaerobic digestion process is utilized to power two generators at the Plant. Waste heat from the engine cooling jacket and exhaust is captured and recirculated through heat exchangers. This system provides heat for the anaerobic digestion tanks and generated electricity is utilized for plant power systems.  Two belt-type filter presses mechanically dewater the liquid sludge daily. The liquid sludge, conditioned with polymer, is pumped to the belt filter presses which discharge dewatered sludge to a conveyor belt. From there it is discharged to sludge hauling containers for trucking to a landfill.

 

After hearing about the many separate processes that the wastewater must complete, it is much easier to understand why sewer rates are higher than water rates. The entire process takes about eight hours from the time the sewage is received until the cleansed water is released back into the Conewango Creek.

 

Many questions followed this excellent presentation.

 

Jim is a graduate of JCC and Clarkson University and holds his Professional Engineers license and Grade 4 Wastewater Operator’s certificate. He oversees the District Heating and Cooling Division of the utility and was the engineer in charge of the recent upgrade of the Wastewater Treatment Facility. A 28-year employee of the BPU, Jim is married, the father of 3 teenage children and in his spare time, is President of the Southwestern Central School Board.