One source of treated drinking water for Western Water Company is the Greater Cincinnati Water Works.  Cincinnati has two sources of raw water, one being the Ohio River and the other is the Great Miami Buried Valley Aquifer.

As with all raw water sources, water travels over the surface of the land or through the ground.  It dissolves naturally occurring minerals and can pick up substances resulting from the presence of animal or human activity.  As with all surface waters the Ohio EPA has classified the Ohio River as highly susceptible to potential contamination.  The Ohio EPA has also classified their portion of the Great Miami Buried Valley Aquifer as highly susceptible to contamination due to the lack of an overlaying protective clay layer, the presence of low levels of nitrates and the presence of nearby potential contamination sources.