ANALYSIS OF TWO KNOWN SECONDARY DRINKING WATER CONTAMINANTS, SULFATE AND HARDNESS, IN WEST GEORGIA GROUNDWATER

Water is a universal solvent that dissolves substances as it moves through soil and rock, picking up impurities and increasing the concentration of certain metals along the way. Hard water is caused by an influx of dissolved metal ions, such as calcium and magnesium, within the groundwater. Sulfate contamination is caused by an influx of the sulfate ion. As part of a geochemistry study, we studied the water parameters of 43 locations throughout the West Georgia area. The purpose was to study the hardness of the water and the sulfate concentration at each of these locations.

The test for hardness required the samples to be filtered and analyzed using the Inductively Coupled Plasma Emission Spectrometer (“ICP”) and each sample was classified according to its individual hardness value. These hardness values were mathematically determined using the calcium and magnesium content measured by the ICP with the MIN = 7.3 ppm, MAX = 150 ppm and the AVG = 5 ppm. Twenty one percent of the samples were classified as soft, while less than 5% were considered hard. Over 51% were classified as slightly hard and 23% as moderately hard. A different protocol was used for testing sulfates and 100% of those tested were all found to be well within the suggested guidelines with the MIN = < 1 ppm, MAX = 25 ppm and the AVG = 5 ppm. While both hardness and sulfate have maximum secondary contaminant levels (MCL) established by the EPA, neither have a health based standard. As secondary water contaminants, their presence can cause side effects that include diarrhea, leaky or corroded household pipes and foul smelling and or tasting water. Nevertheless, these effects while minimal can still prove troublesome to those affected.

The low concentrations of Ca-Mg and SO₄^2- ions are to be expected given the geology of the area. The geology of the Piedmont is composed of both igneous and metamorphic rock ranging in age from 300 to 600 Ma. The rocks have undergone extensive folding and faulting during the rise of the Appalachian Mountains. The chemistry of the groundwater can be high in heavy metals, like iron and magnesium and low in calcium and sulfate. Further studies into other localities, such as mineralized zones in the Villa Rica–Dahlonega Gold Belt, will provide us with a different data set and the ability to compare the water hardness and sulfate concentration of a given area, with its underlying geology.