Buffalo’s water intake is located in the northeastern region of Lake Erie, just before water enters the Niagara River. This region is known as the Emerald Channel, due to the sparkling clarity of its water. Water rushes into the intake through grates and collects in a circular pool where it drops 60 feet to a 12-foot diameter, mile-long tunnel burrowed under the lakebed. When necessary, chlorine may be added to the intake to control the spread of zebra mussels.
The water is gravity fed to an onshore screen house where traveling screens remove large objects such as sticks and other debris that can damage pumps.
Pumps mix and direct the water to a rapid mix where additional PACl may be added at a Rapid Mix to enhance coagulation. The flow is directed to underground basins for flocculation and sedimentation. At the flocculation area, the water is slowly mixed by mechanical paddles to enhance floc formation. This treated water then travels to the settling basins where the heavy floc is allowed to settle out by gravity.
The water, still containing light floc, is directed over rapid sand filter beds where filtration occurs, removing fine floc. A filter aid (a polyaluminum chloride (PACl) is added, when necessary, to enhance filtration. This filtered water enters the Clearwell, where it is stored until needed in the distribution system.
The rapid sand filter beds occasionally need to be cleaned of trapped debris; this is done by backwashing the filters with potable water stored in our washwater tanks. To comply with EPA’s Filter Backwash Recycle Rule the backwash water, containing filter bed debris, is recycled back to the raw water conduit after sludge production in the Thickening Tanks.
The Thickening Tanks concentrate the debris into sludge using a nonionic polymer and settling tubes. The sludge portion is directed by pumps to an onsite lagoon where further processing takes place before removal to a landfill. The decant portion is directed over a weir at the top of the Thickening Tanks to the Raw water conduit, where the water treatment process begins.
As the potable water leaves the plant, a corrosion control additive (a sodium ortho/polyphosphate blend) is used. This serves as a shield against lead leaching into the water from aged residential water pipes and service lines.
The quality and safety of the water is tested by an in house laboratory at every stage of the treatment process. The final product is pumped through the water mains to the community, where further tests are conducted from samples taken throughout the city, including private homes, businesses and public facilities ensuring that water continues to remain high in quality and safety, at your tap.