In this research different methods for measuring water quality indices were conducted to investigate the performance of the newly designed, constructed and operated 9-Nissan water treatment plant, Iraq. Data gathering and implementation took place throughout winter and summer. Water samples were taken periodically, according to the standard method, the re-search was carried out by collecting different random samples for eight months (Jun. 2015–Jan. 2016) and measuring (tur-bidity, total hardness, pH, total dissolved solids, suspended solids, Cl–, Mg2+, Fe2+,NO3–, NH3+) for each sample. Five dif-ferent approaches and methodologies of calculating the water index were applied. The results revealed that the Water Qual-ity Indices varied from 70.55 to 88.24, when applying Canadian Council of Ministers of the Environment Water Quality Index (CCMEWQI) and British Columbia water quality index (BCWQI) geometric weighted mean respectively. All the results, from the five approaches indicated good water quality, multiple regression analyses were conducted for turbidity, total hardness and suspended solids, they found that these parameters are strongly related to each other and to other pa-rameters.
The intensive agricultural use of the land affects both quantity and quality of river water in the catchment area. Such impact is visible also in the Szreniawa River catchment in the Małopolskie Voivodeship. The combination of intensive plowing and soil susceptibility to water erosion are the main causes of soil and nutrients depletion during the heavy rainfall. The aim of the study is to determine changes in the water quality in the Szreniawa River catchment compared to the agri-culture use and precipitation level.
The quality of surface water has been analysed in the river catchment area in three sampling points. The concentration of the total suspended soils in the samples collected after heavy rainfall in August 2017 reached a value of 837 mg·dm–3. The average concentrations of N-NO3 in the years of 2016–2019 ranged from 0.16 to 13.46 mg·dm–3, with the highest val-ues in the summer (up to 13.46 mg·dm–3). The concentration of N-NH4 and P-PO4 in the Szreniawa water was affected by precipitation. The highest value of average concentration of N-NH4 3.00 mg·dm–3 was recorded in the autumn of 2019 in the middle section of the river. The highest value of P-PO4 0.90 mg·dm–3 was recorded in the autumn of 2019 mostly due to water erosion of the loess areas. Erosion has been caused by the short-term heavy rainfall. As a result, suspended solids, soluble and insoluble phosphorus compounds leaked to the river.