In 1992 Alberta Natural Gas Company Ltd (“ANG”) installed a General Electric LM 1600 gas turbine at its Moyie compressor station in southeastern BC, Canada. The unit was packaged by Dresser Rand with a General Electric supplied power turbine. To comply with provincial emissions permitting requirements, and in response to growing environmental concerns, the gas turbine was installed with water injection for exhaust stack NO x control. Water was obtained from an underground well and, after treatment to bring the water to a condition specified by General Electric, was injected into the combustion chamber of the gas turbine. After commissioning, extensive on-site testing was conducted to determine the emissions from the unit using three different techniques, at a variety of load and water injection rates. These tests showed that the expected emission reductions had been achieved and allowed the optimum water injection flow rate to be accurately established for a range of operating conditions.