COMPARISON OF TESTING METHODS OF NATURALLY OCCURRING INORGANIC ARSENIC IN WELL WATER IN CARROLL COUNTY, GEORGIA

Arsenic, an odorless and tasteless semi-metal, occurs naturally in soil and water. This element can be further released into the environment via the decomposition of certain rocks. As of January 23, 2006, the EPA required all municipal water systems to comply with an arsenic standard of 10 ppb (0.010 ppm). At this time the EPA does not have the power to regulate private wells, thus private wells are not subject to the arsenic standard of 10 ppb. Initially fourteen samples of well water were collected in Carroll County, Georgia. The As levels for these samples were analyzed by using a Hach method that utilizes a zinc powder and an oxidizing agent, and the concentration of As of these samples was measured using a colored test strip. This method is not approved by the EPA. Twenty-three additional samples were collected and sent to the University of Georgia’s Laboratory of Environmental Analysis where they were analyzed using EPA certified ICP-MS. Of the original fourteen samples analyzed using the powder technique, two samples detected As levels of 10-30 ppb, eight samples detected As levels less than 10 ppb, and three samples measured As levels as significantly less than 10 ppb. In comparison to the samples tested using the powder method, twenty-two of the twenty-three samples analyzed using the ICP-MS technique yielded As levels significantly less than 10 ppb, with one sample at ~1.5 ppb. To determine if there is a general trend of the powder technique yielding higher levels of As versus the ICP-MS technique, the original fourteen samples sites are being resampled; two samples will be taken from each site with one sample sent to the UGA lab to be analyzed using the ICP-MS method and the other be tested at the University of West Georgia using the powder method.