Sulphate

Sulphate is a primary concern related to crown corrosion in concrete sewers; at concentrations > 250 mg/l may impart bitter taste to water or cause temporary gastrointestinal disorders. Sulphates, which occur naturally in numerous minerals, are frequent discharged into surface waters as wastes from industries such as mining and smelting operations, craft pulp and paper mills. Sulphate is one of the least toxic anions and large quantities would have to be ingested in order for diarrhoea type symptoms to occur.