Spatial distribution of groundwater quality from excellent to unsuitable conditions in rapidly urbanizing Firozabad city of India

In most densely populated and rapidly increasing urban semi-arid areas, checking the quality of groundwater is very important for making sure that drinking water is safe and that groundwater is managed in a way that is good for the environment. The current study focuses on an inclusive hydrogeological evaluation of Firozabad city, Uttar Pradesh, India, by combining geostatistical methods, hydro-chemical analysis, and spatial methodologies to determine groundwater quality and aquifer characteristics. Firozabad, known as the "glass city," is experiencing serious groundwater stress, with development stages surpassing 95%, making it a priority area for water quality studies. The study used both secondary data (topographic maps, geological surveys, and borehole records) and primary data obtained from three important sample sites between July and December 2023. Three-tier aquifer systems with significant clay, sand, and kankar formations were found at depths of 0–80 m, 100–140 m, and 180–300 m below ground level, according to a fence diagram created to show subsurface lithological properties. The findings show three different aquifer systems, primarily composed of clay, sand, and kankar formations, at depths of 0-80, 100-140, and 180-300 meters below ground level. Alarmingly, 80% of the research area has poor to unsuitable water quality for drinking, with only 20% indicating acceptable quality (excellent to good). The highest amount of pollution was reported at Agra Gate (WQI: 576.59). Spatial analysis revealed large pollution hotspots in the southern and southwestern regions with 99% statistical confidence. Strong positive relationships (r=0.99-1.00) between EC, TDS, TH, Ca, Cl, and Mg show that they all come from the same sources of pollution, which are mostly industrial discharge, poor wastewater treatment, and rapid urbanization.