Issue

Introduction State Pressure Impact Response Action Resources Water guide Monitoring Maps Databases

  How we evaluate water quality?

Surface Water Quality

The water quality evaluation data is based on the CSN 75 7221 Czech National Standard, Classification of Surface Water Quality. 
In the terms of their quality surface waters are divided into five classes on the basis of six groups (A to F) of criteria. The factor determining the class into which a particular stream belongs is based on a 90% quantil over a two-year (1996 - 1997) period. Within each of the groups, the most unfavourable criterion prevails. The surface water quality categories and groups of criteria are as follows:

Drinking Water Quality

CSN 75 7111 Czech National Standard (Drinking Water).