In arid, water-stressed nations like Saudi Arabia, decentralized wastewater reuse is essential for enhancing resource resilience and mitigating water scarcity. Bio-Electrocoagulation (BEC) represents a promising hybrid technology for this purpose, yet its true environmental performance has not been rigorously validated within regions reliant on highly carbon-intensive grids. This study addresses a critical gap by presenting the first ISOcompliant cradle-to-gate Life Cycle Assessment (LCA) of a modified BEC system operating in the Arabian Peninsula, a context where the electrical grid intensity exceeds 600 g CO2e kWh- 1. The functional unit was defined as the treatment of one cubic meter of municipal wastewater to fit-for-purpose irrigation standards. The baseline Global Warming Potential (GWP) was quantified at a prohibitively high 8.2 kg CO2e m-3. Detailed impact allocation identified two severe environmental hotspots: grid electricity consumption (accounting for 74% of total GWP) and the production of primary aluminum electrodes (23%). Scenario analysis, including the integration of solar photovoltaic (PV) power and resource circularity measures, confirmed the paramount influence of energy sourcing. Full grid independence via solar PV reduced the GWP by 74% to 2.1 kg CO2e m-3 . When combined with low-carbon electrodes and sludge valorization, the GWP was reduced by over 90% to 0.5-0.8 kg CO2e m-3 , aligning the technology with global climate goals. We conclude that the inherent sustainability of electrochemical water treatment is only realized when decoupled from the high-carbon grid. For successful deployment in high-carbon regions, policy must mandate renewable energy integration and prioritize circular economy measures, such as the use of secondary aluminum electrodes and sludge valorization.