The most common contaminants found in household water in Roanoke County were total coliform bacteria, sodium, hardness, copper and low pH..
Total coliform bacteria presence is an indication that surface water may be entering a well and other more harmful microorganisms may be present. Total coliform was found in 32% of the Roanoke County samples.
Hardness is composed of calcium and magnesium, which originates in bedrock such as limestone. Sodium concentrations above recommended levels are most likely the result of water softeners, used to remove hardness. Sodium can have negative health effects in excess levels.
Low pH (<6.5) can occur naturally in parts of Virginia geology. Although not a concern in itself, low pH can be a driver of how corrosive the water is. Once the water enters the house it can result in metals such as copper and lead leaching into the water from plumbing components that contain these metals, such as brass fittings or copper pipes.