Updated instruction calculating drinking water criterion

As follow-up of the earlier news item of December 23, 2022, a new working instruction concerning the calculation of the 90th-percentile concentration is prepared, due to some changes in the nomenclature of the abstraction points. This instruction can be found on the fate and behaviour methodology page.

Next to this, upon a closer look at the monitoring data, a slight change is made to the list of substances for 2017-2021.   The updated list of substances exceeding the drinking water limit at one or more occasions/drinking water abstraction points can be found at Stoffen - Vewin. Ctgb will use this corrected list in the risk assessment.