| The status of uniform water bodies of river and lakes is evaluated as good or bad by comparing results of the classification of ecological status or potential (on the basis of research results concerning quality indices of waters constituting physico– chemical, biological and hydromorphological elements) with results of the classification of their chemical status if it was planned and completed (on the basis of limit values of chemical quality indices). The worst indicator decides about final assessment. Classification of the uniform water bodies to the moderate or worse ecological status/potential, or to the bad chemical status, shows the bad status of waters, what informs that during evaluated period the uniform water body did not comply the assigned requirements of environmental goals. When the result of assessment showed at least good ecological status/potential, but the chemical status was not assessed or chemical status was good, but it was impossible to classify the ecological status/potential, it was impossible to define the final assessment of the status of uniform water bodies. The assessment of monitored uniform rivers and lakes water bodies was completed with extrapolation or expert assessment of the rest of waters. In the accepted method, when there was no data for precised classification of the ecological status/potential, “at least good” or “below good” classification was assigned, what enabled to define the final assessment of the status. Due to the cyclical planning and programming in water management in Poland, data on the quality of surface waters for: • 2015 refer to the cycle covering the years 2010-2015 for lakes and rivers (lakes studied in 9 voivodeships, and rivers throughout the country), • 2021 refer to the cycle covering the years 2016-2021 for lakes and rivers (lakes studied in 10 voivodships, and rivers throughout the country). A significant reduction in the percentage of water bodies with good water quality in 2021 compared to 2015 results from the inclusion of priority substances in water monitoring that were not previously monitored. In addition, in 2016, the regulation on the method of classifying the status of surface water bodies and environmental quality standards for priority substances was amended, in which the requirements for physicochemical elements were tightened. |
