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~3 <br />literature to the residents as part of their encounters, Radon test kits for air sampling of radon within <br />homes were also placed and picked up by staff by arrangement with the household occupants. <br />Chains of custody for the samples was assured by direct delivery of all non-radon samples to the NC <br />State Laboratory of Public Health in Raleigh. Staff'sent both air and water radon samples to the <br />vendor's private lab for analyses using FedEx next day air delivery. Results were logged into the <br />database for comparison with the county results in general. <br />Discussion of Each Sampled Parameter <br />Bacteriologic Quality <br />coliform bacteria, while not pathogenic in and of itself; is used as an indicator bacteria for the <br />presence of harmful bacteria. The presence of coliform bacteria indicates that surface water <br />contamination is present in the well, either tinough a shallow, unprotected vein of water (generally <br />less than 60 feet from the ground surface), or from ui inadequate length of casing or other well <br />construction deficiency,. For drilled wells, the casing is the metal pipe that extends from the ground <br />surface and goes into solid rock (bedrock) to seal out the shallow groundwater, which is poor in <br />quality. Hand-dug wells and bored wells rely on shallow groundwater and are expected to contain <br />coliform bacteria.. Shallow wells are also more prone to going dry or getting muddy during extended <br />periods of drought. For these reasons, current Orange County well construction standards require at <br />least 63 feet of casing on all new drilled wells. <br />Bacteria -Mill Creek <br />Health effects -Because coliform is used as an indicator of contamination, a well with <br />persistent coliform bacteria or with fecal coliform present should be considered an unsafe <br />source of drinking water. The presence of coliform indicates that conditions are favorable <br />for the presence of other bacteria that catz cause health problems such as diarrhea, upset <br />stomach, cramps, and vomiting. <br />Remedial action -When coliform is present, the well should be chlorinated thoroughly and <br />retested, If total coliform bacteria return after this treatment, the owner can opt to either <br />attempt to repair the well by installing a liner, or to install a treatment system on the well, <br />typically a chlorinator or ultraviolet light disinfection unit. If the well exhibits persistent <br />fecal coliform, the well should either be replaced or repaired with a liner. Owners of a well <br />Page I 1 of 47 <br />