The background of commercial liquid scintillation spectrometer has been reduced by a factor of six by locating it deep in the wall of Warraganba Dam, near Sydney, New South Wales. This resulted in an increase in the maximum carbon-14 age of between 5000 and 8000 years assuming a total counting time (sample and background) of 2000 have been obtained by increasing the counting time from 2000-8000 minutes, but this is inconsistent with the practical requirement of an acceptable sample throughput.