Assessment of the effects of industrial development on surface water quality in Namanve industrial and business park, Mukono municipality

Abstract

Industrial parks adversely pollute the environment due to economic priorities, thus affecting essential community ecosystem services. This study assessed the trend in industrial expansion and its effect on surface water quality in Namanve Industrial and Business Park (NIBP). High resolution satellite historical images covering the study area were acquired from Google Earth Pro archives and used examine the spatial and temporal changes in the study area between 2014 and 2022 and the prediction of 2030 scenario. Water samples were also collected from the Namanve stream at four purposively selected locations in relation to the four Industrial Blocks and taken to the Makerere chemistry Laboratory for physicochemical and heavy metal properties’ analysis. A household survey also ensured in the communities surrounding the Industrial Park to collect socioeconomic data on water sources’ contamination status and the most significant drivers of surface water contamination. Satellite imagery data underwent supervised classification procedures in ArcGIS 10.8.2 and QGIS 3.28 to create land use and cover extent and change facets and predict future changes. Water quality laboratory results underwent descriptive and Multivariant statistical analysis whilst household survey data was analysed using multiple response procedures and Binomial statistical test analysis at inferential level. The study found a significant expansion of industrial activity between 2014 and 2022 (r2=0.86), which was linked to substantial surface water contamination, marked by altered physicochemical parameters; highest turbidity levels (318±21) on the South Block C. The highest value pH levels (8.1±0.14) were recorded mid-stream and elevated heavy metal concentrations with the highest value recorded for Zinc (0.24±0.18) in the South Block B. Industrial development is a primary driver of this contamination but other drivers like runoff and waste disposal also contributed to water pollution significantly (p≤0.05). However, projections suggest a decline in industrial land use between 2022 and 2030, with natural cover regaining ground. This shift may potentially mitigate some of the negative impacts on surface water quality observed in the earlier period. The spatiotemporal variation in water quality highlights the need for continued monitoring and management of both industrial activities and other pollution sources to ensure the long-term health of the NIBP's aquatic ecosystem. Therefore, industrial infrastructural developments should be restricted in the area; there is need to enforce water decontamination measures through bioremediation and conservation of natural wetlands and; NEMA should enforce environmental regulations governing discharge of hazardous industrial and municipal waste.