BALKAN PHYSICS LETTERS c  Bogazici University Press BPL, (2008) TRITIUM MEASUREMENTS IN DRINKING WATER IN ESKIS ¸EHIR, TURKEY G. TOP Graduate School of Sciences, Eski¸ sehir Osmangazi University, Eski¸ sehir, 26480 Turkey E. ALGIN Department of Physics, Eski¸ sehir Osmangazi University, Eski¸ sehir, 26480 Turkey (received ... ; accepted ...) Abstract. - Tritium concentrations in drinking waters are determined by using Low-Level-Liquid Scintillation Counter and are compared to the accepted limits of tritium by World Health Organization (WHO) and Turkish Standard Institute (TSE). For tritium analysis in drinking water, the city Eski¸ sehir and its surroundings are chosen as pilot areas. Water samples are enriched by electrolysis technique before Liquid Scintillation Counting. Water constitutes about three quarters of our planet and human body. Consider- ing the daily consumption level of drinking water, the purity and cleanliness of the consumed water is very important. The cleanliness of the water also depends on the tolerable levels of radionuclide materials in water. One of the radionuclides in water is tritium. Tritium is a radioactive isotope of hydrogen that emits low-energy beta particles, with a maximum energy of 18.6 keV. The half life of tritium is 12.6 years [1]. Tritium is naturally produced through reac- tions of atmospheric 14 N and 16 O atoms with cosmic rays in the upper atmosphere, and in small amounts in the earth crust from the neutron capture reaction of 6 Li in rocks containing uranium [2]. Artificially, after the series of nuclear tests conducted between 1954 and 1963, environmental tritium levels are increased as a result of the releases of large quantities of tritium injected into the stratosphere and to a smaller extent into the troposphere [3]. Tritium is a part of tritium water (HTO, T 2 O), can exist as a gas (HT, T 2 ), and also is a part of organic and inorganic compounds that contain hydrogen [4]. Liquid scintillation counting is the most commonly used technique for determining