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Chlordane 29 <br /> Until 1988, chlordane had been used extensively as an insecticide, particularly in soil treatment for <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/l). <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 a non-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 2Oug/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 a follow-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 is 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 and <br /> organic contaminants were conducted in March 2010. <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 />