The work described in this paper was conducted under an Electric Power Research Institute (EPRI) Contract RP1691-2, “Evaluation of Shale Oil Residual as a Utility Gas Turbine Fuel.” An FT4A-9 engine was run at Long Island Lighting Company (LILCO), and a selected single-can combustor from the LILCO engine was run at United Technologies on No. 2 petroleum distillate fuel and hydrotreated Paraho shale oil residual, with and without water injection. The use of hot water injection was successfully demonstrated, with reduced NOx emissions and low smoke on both fuels. The EPA NOx limit of 125 ppm for fuels containing 0.25 percent nitrogen or greater was close to being met at 18.5-MW engine power with shale oil residual at a water-to-fuel mass ratio of 0.79.