Electrocoagulation process efficiency to remove high concentrations of boron from surface water is studied. A glass reactor with a volume of 2.744 L installed with aluminum electrodes is used. The working parameters of initial pH (6, 7.4, 8.5, and 9); initial boron concentrations (1,998, 998, and 500 mg/L); and the presence of supporting electrolytes (15 mM of NaCl, Na2SO4, and KCl) were tested with a current density of 10 mA/cm(2) for 90min. The optimum results were achieved with the initial pH 8.5. The removal efficiencies decreased with the increasing initial boron concentration, and the highest removal rate was measured as 55% with 500 mg/L initial boron concentration. Initial boron concentration and boron removal efficiency are both found negatively correlated with the weight losses from the electrodes. As a result of principal component analysis (PCA), the presence of electrocoagulation supplying ions in the solution, the level of electric current density, and the valance of the electrolyte metal are found as the major factors influencing boron removal efficiency. (c) 2017 American Society of Civil Engineers.