INORGANIC ARSENIC IN THE METAVOLCANIC BEDROCK OF WEST GEORGIA

Arsenic occurs in domestic drinking water supplies around the world. The Environmental Protection Agency standard for drinking water is 10 ppb. Arsenic is naturally occurring in groundwater so it should be monitored. Arsenic can cause many health issues, some of which can lead to death. In fact millions of people worldwide are in danger of arsenic poisoning. A USGS study of 1,389 domestic wells in the United States found that 7% contained arsenic levels above 10 ppb. This research in west Georgia is being conducted after a study in New Hampshire has shown that 19% of the wells tested have arsenic concentrations above 10 ppb. Georgia’s Piedmont shares a similar sulfide rich bedrock zone similar to the rocks in the New Hampshire study. In the sulfide rich zone in Georgia, there is an abundance of meta-volcanic rock that could leach arsenic. Arsenic sampling is minimal in Georgia, but this should be looked at after studies have been done in areas with the same bedrock that show high levels of arsenic. Both deep drilled bedrock and shallow wells in saprolite are found in Georgia.

As part of undergraduate research in groundwater environmental geochemistry at the University of West Georgia, wells were sampled and tested for arsenic in Carroll County, Georgia. We tested 64 private wells and 15 shallow campus research wells. The campus research wells are shallow bored wells in the floodplain of the Little Tallapoosa River. The campus research wells had detectable arsenic. These wells are all in an area of amphibole and hornblende which is known to leach arsenic. Over 50 domestic wells in Georgia were sampled and tested for arsenic levels using a non-compliant EPA method. Using a portable test strip they were screened for arsenic. The color test strip has 0 ppb, 10, 30, 50, 100, 300, and 500 ppb reading levels. All samples over 10 ppb will be resampled and retested and will be sent to an outside lab for testing by an EPA approved method. This research focuses on the relationship between arsenic in well water and the type of bedrock. GPS positions were plotted on a new geologic map of Carroll County. Results indicate that the highest readings of 30-50 and 50-70 ppb of arsenic were all in the meta-volcanic rock type. Only 16% of the samples that contain <10 ppb arsenic are in meta-volcanic bedrock. Additional well water sampling will be done in other rock units.