The most common contaminants found in household water in Pulaski County were hardness, total coliform bacteria, sodium, total dissolved solids, and E. coli.
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.
Total coliform bacteria presence is an indication that surface water may be entering a well and other more harmful microorganisms may be present. E. coli were found in 12% of the samples and are a sign that human or animal waste is entering the water supply.
Total dissolved solids, or TDS, is a measure of all dissolved impurities in water, and can be made up of sodium, nitrate, or other dissolved contaminants. It is a nuisance contaminant.