Arsenic contamination in groundwater poses a major health threat globally, particularly in South and Southeast Asia, where millions rely on arsenic-laden water sources. This study investigates the effectiveness of electrocoagulation (EC) as a treatment method for arsenic removal, emphasizing its operational simplicity and cost-efficiency. The main objective was to evaluate arsenic removal efficiency using EC with aluminum and iron electrodes under varying conditions and to identify optimal operational parameters through experimental design. Synthetic wastewater samples with arsenic concentrations of 100 ppb and 300 ppb were treated under different pH levels, current densities, and reaction times. A Box–Behnken design within the response surface methodology (RSM) framework was employed to systematically explore parameter interactions. The results showed that at 100 ppb, arsenic removal efficiency reached 99.93% under the optimal conditions of reaction time 52 minutes, pH 8.9, and current density 12.5 A/m². For the 300ppb concentration, maximum removal efficiency was slightly lower at 99.41% under the optimal conditions of reaction time 42 minutes, pH 7.6, and current density 22 A/m². Statistical modeling confirmed strong predictive accuracy for the 100ppb scenario (R² = 0.997), while a slightly reduced fit was observed for the 300ppb case (R² = 0.802). The findings demonstrate the viability of EC as an efficient, scalable treatment for arsenic-contaminated water, with optimal performance at neutral pH and moderate current densities. This research provides valuable insight into designing decentralized water treatment systems, particularly in resource-constrained settings, and supports EC as a promising technology for mitigating arsenic exposure in vulnerable communities.