Halides, particularly Br- and Cl-, have been used as indicators of potential sources of Na+ and Cl- in surface water and groundwater with limited success. Contamination of groundwater and surface water by Na+ and Cl- is a common occurrence in growing urban areas and adversely affects municipal and private water supplies in Illinois and
other states, as well as vegetation in environmentally sensitive areas. Neutron activation analysis (NAA) can be effectively
used to determine these halogens, but often the elevated concentrations of sodium and chlorine in water samples can give rise
to very high detection limits for bromine and iodine due to elevated backgrounds from the activation process. We present a
detailed analytical scheme to determine Cl, Br and I in aqueous samples with widely varying Na and Cl concentrations using
epithermal NAA in conjunction with Compton suppression.