<p>This work explored the toxicological effect of heavy metal in ground water of a Tannery Industrial Estate of Dhaka, Bangladesh and appraisal the groundwater aptness as drinking and irrigation water. The results revealed the worthiness of water for drinking and irrigation purposes as the physicochemical properties (pH, EC, salinity, and TDS), cations (Na⁺, K⁺, Mg2⁺, and Ca2⁺), and anions (F⁻, Cl⁻, SO₄2⁻, and NO₃⁻) were found within the permissible level propounded by various authorities. Among the analyzed heavy metals (As, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sr, and Zn), Hg (&gt; 0.05) in both wet and dry seasons, and As (&gt; 0.1) only in the wet season exceeded the permissible limit according to WHO (2017), which consequently influenced the groundwater evaluation indices. Seasonal variation was present prominently in all the evolution methods, and values were higher in the dry season compared to the wet season. The groundwater was irrigation-suitable, although the total hardness (TH) of groundwater was high (TH &gt; 300). During both seasons, Hg and Ni were the most significant contributors to the non-carcinogenic and carcinogenic health risks through dermal exposure, respectively, whereas As contributed most through ingestion exposure. Children were more vulnerable to health risks than adults; also, both age groups faced a higher risk during the wet than the dry season, primarily due to ingestion rather than dermal exposure. This study presents the first data on the trends of heavy metal concentrations in groundwater from the Tannery Industrial Estate of Dhaka, Bangladesh and their associated health risk, thus providing foundational information for future research. </p>