Orange County NC Website
Browse       Search
been established by the EPA. The incidence of lead is usually tied to corrosion of <br /> solder joints in metal household pipes and alloys in pumps and faucets. Elevated <br /> lead exposure is known to cause delayed physical and mental development in <br /> babies and young children and also has been linked to kidney disease. <br /> F. Organic Compounds <br /> 9 P <br /> The ground water samples collected in the County were also examined for <br /> certain organic compounds that may indicate the presence of herbicides or <br /> petroleum products. Specifically, the water testing checked for atrazine-type <br /> compounds and total petroleum-hydrocarbon compounds, including BTEX ( a <br /> common measurement of benzine, toluene, ethylene and xylene). Atrazine is a <br /> frequently used herbicide. <br /> None of the compounds were detected in the samples, and this result in the <br /> geographically and statistically sampled wells may indicate that contamination by <br /> organic compounds is not a widespread problem in the County. Further work <br /> would be needed to more comprehensively determine this, however. <br /> G. Radon <br /> Water-borne radon is a naturally-occurring substance from the decay of uranium <br /> bearing rocks. It is the dissolved state of radon (or radium-222) that poses <br /> potential health risks. As ground water is exposed to air through showers and <br /> running faucets, radon present in the water may diffuse into the air. Thus, there <br /> are two potential means of exposure to radon — ingestion and inhaling. Because <br /> radon exposure can occur in two ways, EPA has had difficulty addressing <br /> regulations, eventually deciding on a "multi-media" approach. If no State or EPA- <br /> approved mitigation program exists, the MCL for radon is 300 picoCuries per liter <br /> (pCi/L). If there is an approved mitigation program, then 4000 pCi/L is proposed. <br /> Results from the wells sampled in this study used these standards for <br /> comparison. <br /> The results of this sampling are the most significant of all the water quality <br /> findings, as some limited incidence of high radon readings were found in the <br /> County. These high readings are not completely unexpected. In 1998, findings of <br /> high radon levels in nearby Guilford County (in similar geologic formations) led to <br /> some expectation by the Committee that higher than average radon findings <br /> would also be observed in Orange. <br /> The range of radon activity in Orange was quite dramatic, from a low of 38 pCi/L <br /> (picocuries per liter) to 4462 pCi/L (please see Map 2) . The median finding of all <br /> samples was 405 pCi/L, above the 300 pCi/L standard suggested by EPA. <br /> Generally, the radon activity was highest in felsic (silica and feldspar) rocks and <br /> lowest in mafic rocks (iron and manganese base). <br /> 8 <br />