Anthropogenic and Natural Impacts on Surface Water Quality: The Consequences and Challenges at the Nexus of Waste Management Facilities, Industrial Zones, and Protected Areas

The objective of this study was to evaluate the physicochemical characteristics of surface waters near an old landfill, to assess water quality using the Water Quality Index (WQI) and the Comprehensive Pollution Index (CPI), and to identify factors influencing surface water composition using multivariate statistical analysis. The analysis of temporal changes of 15 surface water parameters (pH, EC, Cl−, NH4+, SO42−, BOD5, CODCr, TOC, Zn, Cd, Pb, Cu, Cr, Hg, and PAH) was complemented by the investigation of surface water flow, ambient temperature, and precipitation. A twelve-year monitoring period was considered, focusing on monitoring sites located along a watercourse in the area of the Radiowo landfill (Poland). No significant correlations were found between precipitation and surface water quality parameters in the outflow direction. The results showed that the average WQI values ranged from 63.06 to 96.86, while the average CPI values ranged from 0.56 to 0.88, indicating good water quality or low pollution, respectively. The temperature had a greater influence on the physicochemical parameters than the precipitation, especially on the parameters of contamination by organic compound (correlations between temperature and BOD5, CODCr, and TOC of 0.40, 0.50, and 0.38, respectively). Significant correlations were observed between EC, Cl−, NH4, BOD5, CODCr, and TOC in the outflow direction of the landfill. In addition, surface water flow showed a significant moderate negative correlation with pH (r = -0.44) and a moderate positive correlation with Cu concentration (r = 0.47) downstream of the landfill. The analysis of surface water quality monitoring, coupled with the critical evaluation of global research, has made it possible to understand the variation in surface water quality and the factors that influence it. The study confirmed that given the complex nature of Municipal Solid Waste (MSW) landfills, understanding the dynamics and factors affecting water quality is essential for effective water protection and management and achieving the Sustainable Development Goals (SDGs).