Concentrations of radionuclides in Lake Ontario water from measurements on water treatment plant sludges

The purpose of this investigation was to compare the results of indirect measurements of radionuclide concentrations in water with those measured directly. The levels of 137Cs and 226Ra in western Lake Ontario nearshore waters were derived from high-resolution γ-spectrometric measurements on aluminum hydroxide sludge samples obtained from four water treatment plants. The concentrations of 137Cs evaluated by this indirect technique averaged 0.036 compared with 0.023pCi 1-1 measured directly, while those of 226Ra averaged 0.047 compared with the direct measurement of 0.03 pCi 1-1. The concentrations of a number of other radionuclides at these locations were also calculated from the sludge γ-ray measurements. (author)