Water Treatment

Located 3 to 5 miles offshore in Lake Erie, a crib protects the top of the pipe into which lake water flows, preventing large pieces of debris from entering the pipe.

Beneath the bed of Lake Erie, an intake tunnel, between 7 to 10 feet in diameter and several miles long, brings water to the treatment plant. Near the shore end of the tunnel, we add a chemical called Potassium Permanganate (A). Potassium Permanganate is an oxidant that helps more effectively remove particulates. It also helps control taste, odor, and color as well as quagga mussels and algae.

Screens filter out mussel shells, fish, and other large debris before the water enters the treatment process.

Raw water pumps pull in the water from Lake Erie to begin the treatment process. At the raw water pumps we add Powdered Activated Carbon (B). It absorbs organic material that can cause unpleasant tastes and odors. Contaminants attach themselves to the carbon granules and settle out in the sedimentation and filtration steps.

During the rapid mix step, Aluminum Sulfate (C), or Alum, is added and quickly mixed into the water. Alum is added as a coagulant to help small particles stick together so that they can be removed more easily.

Water moves through three zones of mixing, with each zone mixing at a slower speed than the one before to allow organic and inorganic material to clump together as floc. 

Water moves slowly through large settling basins where heavy clumps of floc settle to the bottom of the tanks and are removed. The cleaner water passes through the top of the tank to the next phase.

At the filters, gravity pulls water through filter media made of two feet of anthracite over one foot of sand to remove finer impurities.

At this step, we add Chlorine (D) – to kill pathogens, Fluoride (E) – to promote dental health, and Orthophosphate (F) – to prevent pipe corrosion. The water then slowly moves through the finished water reservoir to ensure chlorine has adequate time to kill all bacteria and viruses.

The finished water is pumped through the distribution system to customers. Throughout the treatment process, we test the water to make sure each stage is working effectively and only safe, clean water is produced and delivered to customers.