Nitrate (NO3-) is considered one of the top 10 drinking water pollutants all around the world, with a restrictive maximum concentration of 10 mg NO3--N L-1 [1]. Above this level, human health can be highly threatened. Recently, the electrochemical reduction of nitrate (ERN) has showed promising results to reduce and transform NO3- into innocuous nitrogen gas (N2 ) or decentralized ammonia (NH3 ) for agricultural use [2]. However, most of the works reported so far use platinoid materials (expensive and endangered elements) as electrodes and are mainly linked to the study of the reaction mechanism; lacking research closer to real life applications like the one presented here, which is based on treating natural water sources using an earth-abundant material as cathode in a galvanostatic and membraneless system. The first step in this study aimed to provide a framework for selecting promising earth-abundant elements against the platinum group elements to electrocatalytically convert nitrate under identical operating conditions [3]. Tin (Sn) was identified as the most encouraging material to convert NO3- to N2 , outperforming Pt around 64x in terms of selectivity. A second step was to verify in what extent the most common anions/cations present in natural water sources (ground, brackish and brine waters) affect the ERN on Sn cathodes. The results showed that the co-existence of other ions besides NO3-in solution can cause a 4x decrease in the ERN activity in comparison with a solution only containing NO3-. This is due to inorganic scaling formation on the cathode surface. Brucite (Mg(OH) 2 ), calcite (CaCO3 ) and dolomite (CaMg(CO3 ) 2 ) formed on Sn cathode during the electrolysis promoted the decrease of the ERN efficiency by creating a physical barrier on the electrode surface. Half of the maximum ERN performance was recovered by employing a chemical softening pre-treatment to the solution prior to ERN. Finally, encouraging electrolysis results, on a bi-dimensional Sn cathode using an electrochemical flow reactor working in batch mode during 180 min were obtained: nitrate conversion (~ 50%), selectivity towards N 2 (~70%) and ammonia (~15%), and electric energy per order (~36 kWh m-3 order -1 ). These outcomes still show space for improvement that can be done by using nano-enabled three-dimensional Sn electrodes that specifically tailor the selectivity towards the desired by-products. This will boost the performance of the ERN systems, making them even more competitive [1] World Health Organization (WHO), Nitrate and nitrite in drinking-water, (2016). [2] S. Garcia-Segura, M. Lanzarini-Lopes, K. Hristovski, P. Westerhoff, Appl. Catal. B: Environ. 236 (2018) 546-568. [3] A.S. Fajardo, P. Westerhoff, C.M. Sanchez-Sanchez, S. Garcia-Segura, Appl. Catal. B: Environ. 281 (2021) 119465.