@ARTICLE{Jarnuszewski_Grzegorz_Sewage_2025,
 author={Jarnuszewski, Grzegorz and Wołejko, Lesław and Durkowski, Tadeusz and Stańko, Robert and Chwyć, Natalia},
 number={No 67},
 pages={253-263},
 journal={Journal of Water and Land Development},
 howpublished={online},
 year={2025},
 publisher={Polish Academy of Sciences; Institute of Technology and Life Sciences - National Research Institute},
 abstract={The article assesses the current condition of two lacustrine habitats of the Natura 2000 PLH32006 site, located within the Płonia River catchment. The state of water and sewage management in this catchment area may seriously affect these habitats. All lakes representing Natura 2000 habitats in this area – mesotrophic lakes and eutrophic lakes were investigated in the vegetational season of 2019. Surface water and sewage of the Płonia River catchment were analysed for NH4+, NO3−, PO43−, Cl−, electrolytic conductivity (EC), and pH in the period 2019–2021. Our research shows that the vast majority (99.5%) of the area of mesotrophic lake habitat is evaluated as unfavourable (U2 = bad). The area of eutrophic lakes has increased from 929.28 ha to 1.127.07 ha, and 91% of this habitat type is also unfavourable state (U2). This general result depends strongly on the negative evaluation obtained for Miedwie Lake. In the tested surface waters, the concentration of NH4+, PO43− and electrolytic conductivity clearly point to a poor condition of surface water (below class 2). Analysis of the waters from sewage receivers at operating treatment plants (including chloride concentration) indicates that they pollute the waters. Our research discloses the negative influence of water and sewage management on the condition of the protected wetland and water ecosystems in the Plonia Valley Natura 2000 sites.},
 type={Article},
 title={Sewage management threaten protected Nature 2000 habitats in the Płonia River catchment – North-Western Poland},
 URL={http://czasopisma.pan.pl/Content/137933/PDF/2025-04-JWLD-24.pdf},
 doi={10.24425/jwld.2025.156057},
 keywords={charophyte, Natura 2000 habitats, sewage treatment, surface water, water pollution},
}