7.6.5 Application of reference levels

This guidance deals only with situations where the radionuclide concentrations arise either from natural sources or more rarely as the result of past practices (such as abandoned mining operations). It specifically does not apply to situations where the radionuclides arise from current practices under regulatory control, such as an operating uranium mine.

Therefore, the guidance should not be used to support an increase in the radionuclide concentrations of drinking water as a result of a planned exposure situation, on the grounds that the overall dose levels remain below 1 mSv/year.

As stated in Section 7.6.3.4, a national reference level of 1 mSv/year should be applied for doses resulting from the consumption of radioactivity in drinking water (ARPANSA 2017). It is recommended that the relevant health authority or drinking water regulator assess the reported radiological water quality data to determine that the reference level has not been exceeded. If the reference level has been exceeded, the need for protective measures should be considered with all relevant stakeholders. More information about the assessment and operational response can be found in Information Sheet 2.2.