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Chlordane <br />Until 1988, chlordane had been used extensively as an insecticide, particularly in soil treatment for20 <br />termites. It is considered to be only slightly mobile in soil and persists in the environment for a long <br />period of time. Chlordane health risks include organ damage and cancer. <br />EPA has set a maximum contaminant level (MCL), at 2ug/L or 2 ppb. The sample indicating the <br />presence of chlordane was well below this level. Water treatment technologies are available to <br />remove these contaminants. <br />Dieldrin <br />Dieldrin is another chemical that may be present in groundwater as a result of pesticide use. There is <br />no established maximum contaminant level (MCL), however the North Carolina Department of <br />Public Health recommends a level below the odor threshold of 0.2ug/1 for drinking water to protect <br />against possible adverse health effects. <br />Petroleum and Volatile Organic Compounds - <br />Of the 11 wells, two had low, but measurable amounts of Methyl tert-butyl ether (MTBE) (3.4 <br />and 0.6 ug/I). <br />MTBE is an additive of gasoline used as an oxygenate and to raise the octane level. MTBE is <br />introduced into groundwater through leaking underground gasoline storage tanks or by spilling <br />gasoline onto the ground. Once released, it is very mobile in the soil and may contaminate large <br />quantities of groundwater as it is persistent and highly soluble. MTBE is not classified as a human <br />carcinogen, however at very large doses can present non-cancer related health risks. Water <br />treatment systems can be installed to remove volatile organics to anon-detectable level. <br />Health-based limits for MTBE are not issued by the EPA and additional research is ongoing. The <br />odor threshold value of 20ug/1 is referenced as a recommendation for drinking water. <br />The organic test results were reviewed by the NC Division of Public Health toxicologist and he <br />concluded that the water is safe for continued usage, but recommended afollow-up sample for <br />MTBE which has been scheduled for these two wells. <br />Follow-up Plans <br />Owners of the wells will be notified of the sampling results by individual comprehensive reports <br />including appropriate recommendations. Staff are available by phone and email for any consultation <br />requested by residents. Any deficiencies in well head protection will be noted and recommendations <br />given as to how the well can be properly protected. Follow-up sampling for bacteriologic, inorganic <br />and organic contaminants will occur over the coming weeks. <br />Limitations <br />The samples taken and analyzed are a specific point-in-time evaluation of the water supplies. There <br />are many factors that can influence a water supply, for example, failure to chlorinate a well after <br />replacing a pump can result in bacteriologic contamination of the well. Wells that are drilled where <br />high iron or manganese concentrations are present can degrade over time and require remediation or <br />treatment as the well ages. Periodic water tests are the best way. to ensure that a water supply is <br />continually safe for human consumption. <br />It is important to note that this survey was not intended to be a groundwater assessment. Wells that <br />were not used for drinking water were not included in the sampling. Furthermore, the survey was <br />not an attempt to make any conclusions or inferences related to the landfill operation. <br />Page 8 of 11 <br />