one of the factor to ensure good water quality

Lab facility.

A New Zealand laboratory has come first of 70 laboratories around the world in water dating.

The GNS Science tritium and water dating laboratory in Lower Hutt was four times more accurate than the second-placed laboratory in the international comparison run by International Atomic Energy Agency.

Each laboratory was asked to measure tritium concentrations in six blind water samples. GNS Science was the only one to get all six right.

Laboratory manager Uwe Morgenstern said the result was gratifying.

"We can now say unequivocally that we are the most accurate tritium dating lab in the world.

"That will help considerably in attracting new business, especially from Europe and North America."

Tritium is a rare isotope of hydrogen, which can be used to find out when water falls to earth as either rain or snow.

GNS's tritium measurements have been adopted by the New Zealand government as a benchmark for the security of drinking water from aquifers, as water age indicates if groundwater is free of pathogens.