An age-old and cost-effective water treatment method is drawing river water through the aquifer adjacent to the river. This filtration technique, known as riverbank filtration (RBF), entails drawing water from the river or lake through a hydraulically connected aquifer. This study focused on assessing the enhancement in the quality of river water filtered through a 31-m thick sand-gravel unconfined aquifer at three infiltration wells (IWs) surrounded by the Rushikulya River in Badamadhapur, Odisha, India. The distances between the river and the infiltration wells are 27 m (IW1), 45 m (IW2), and 100 m (IW3). As water travels through the aquifer to the infiltration wells, it undergoes mineralization from the river. The water from IWs demonstrated a 1.9–2.3 log reduction of turbidity during the monsoon, a 0.5–1.4 log reduction of turbidity in the pre-monsoon, and a 1–1.4 log removal of turbidity in the post-monsoon periods. Total coliform saw a reduction of 95.6–98.8% in IW1, 98.1–99.6% in IW2, and 98.8–100% in IW3. Similarly, UV-absorption in the Rushikulya River ranged from 0.095 to 0.16 cm−1, while UV-absorption in the IWs fell within the range of 0.018 to 0.05 mg/L. Notably, a higher removal efficiency of pollutants was observed at the infiltration well located at a greater distance from the river.