The ANL-E domestic water is supplied by four wells that are described in Section 1.7 and Table 6.1. Their locations are shown in Figure 1.1. According to the National Primary Drinking Water Regulations,23 the ANL-E system is classified as a nontransient, noncommunity public water system, since it regularly serves at least 25 of the same persons over six months of the year. This designation determines the parameters to be monitored and the frequency of monitoring. Monitoring of the ANL-E domestic water supply is conducted to demonstrate compliance with applicable regulations and to obtain information on the concentrations of other constituents.