Saskpower's electric system, like that of many utilities in North America, is increasingly experiencing harmonic distortion problems. SaskPower has adopted harmonic limit standards along the guidelines proposed in the IEEE 519-1981 standard and revised in the IEEE 519-1991 standard. These limits are discussed and a detailed method is given to evaluate a customer's installation. Two example cases are presented including the evaluation of a gas pipeline compressor station installation and an oil field installation.<<ETX>>