SITE SELECTION FOR WATER AND SEWAGE TREATMENT PLANTS IN A RIVERBANK CITY: A CASE STUDY ON PAONTA SAHIB, HIMACHAL PRADESH

Abstract

Many urban areas are facing water crisis as a result of years of mismanagement of waste water, worsened by urbanization, population expansion and climate change. Efficient sewage treatment plants (STPs) and water treatment plants (WTPs) are crucial for sustainable urban development and management. This becomes more important for a riverbank city, where the tendency is to dump untreated waste in the river, thus making it unhealthy. This study addresses this burning concern by identifying optimal locations for these water infrastructure in the riverbank city of Paonta Sahib, Himachal Pradesh, India, using a GIS and AHP-based approach. The challenges in this unique topography include constrained land availability, potential harm to sensitive river ecosystems, and inadequate sewage systems, forcing the direct release of large volumes of untreated wastewater into the rivers. The research methodically classified the study area into zones and sub-zones. Further, it identified nine critical parameters for WTP and STP site selection, emphasizing their importance through rigorous Analytic Hierarchy Process (AHP) weightages. These weights contributed in a Geographic Information System (GIS)-driven weighted overlay analysis, producing a suitability map that pinpointed promising locations. Subsequently, a hierarchical order of preference was established based on Technique for the Order of Preference by Similarity to Ideal Solution (TOPSIS) and Weighted Sum. It's crucial to note that this analysis brought to light significant differences in performance scores between WTPs and STPs, highlighting the considerations for these distinct facilities. Furthermore, the study identified instances where some locations within WTPs and STPs were closely situated, suggesting opportunities for resource optimization by consolidating these sites and potentially eliminating redundancy. This principle extends to areas where operational WTPs or STPs exist, offering prospects for infrastructure enhancement and rearrangement. This research highlights the critical need for sustainable wastewater management strategies and efficient treatment plant siting, particularly in environmentally sensitive areas like riverbank cities.