Agenda 05-28-2002 - Laserfiche WebLink

Browse Search

III. What We Have Learned: Water Quality Ground water quality issues may range from very localized quality concerns (whether naturally occurring or synthetic contaminants) to larger, wide-ranging water quality problems. There are many locations in North Carolina and other states that have serious water quality concerns, whether from naturally occurring substances or from municipal, agricultural or industrial contamination. Fortunately, in this County, we have relatively good water quality. While there are some portions of the County that are more susceptible to contamination, the County's land use policies limiting high-water use or polluting industrial operations has resulted in few episodes of contamination, and all of the known areas of contamination have been identified and mapped. While there are occasional dialogues about potential water quality (such as at the landfill), there are few water quality problem areas in the County, and those that do exist are very localized. This is due primarily to generally good ambient ground water quality, and good well-siting and construction practices (the County's Health rules for well siting and construction exceed the State standards). The primary water quality concern in the County is from naturally-occurring contaminants, such as iron and manganese. These metals, naturally found in the County's soil and bedrock, produce rust-colored stains and other nuisance-type water problems. Another potential concern identified is from water-born radon, as noted below. As a part of the USGS Ground Water Resource Investigation (GWRI), extensive well-sampling was conducted at 51 wells across the County. These wells were selected to maximize geographic and hydrogeologic distribution. NOTE: A statistical summary of results is presented in Table B on page Z6. Results of the well-testing confirm the County's generally good ground water quality. The following sub-sections address the different types of well-testing conducted, with a brief summary of the findings of those samples. The average well in the sample was 205 feet deep, and about three years old. A. Field Parameters (pH,conductance,temperature,dissolved oxygen,alkalinity) Measuring field parameters such as pH and dissolved oxygen offers a broad characterization of water quality, when taken together. The parameter pH measures the acidity or lack thereof in water. Water that has a pH measurement of 7 is considered neutral, while waterwith pH less than pH 7 is considered acidic, and water with a pH greater than 7 is considered basic. Acidic water contributes to corrsiveness and can damage plumbing systems. The 5