Maximum permissible concentration of copper in drinking water in mg/L is

The 1959 WHO International Standards for Drinking Water suggested that concentrations of copper greater than 1.5 mg/litre would markedly impair the potability of the water. However, in the first edition of the Guidelines for Drinking Water Quality, published in 1984, a guideline value of 1.0 mg/litre was established for copper, based on its laundry and other staining properties.