Recent revisions of the Clean Air Act have mandated increasingly stringent controls on nitrogen oxide (NOx) emissions. Likewise, the Canadian Council of Ministers of the Environment have adopted interim guidelines recommending low NOx technology. Combustion of fuel in engines for transportation and in stationary power generation produce over 90 percent of all NOx emissions. In particular, large scale, low speed, 10000-10,000 hp natural gas engines currently used to drive natural gas pipeline compressors may be classified as major NOx sources individually. Under various State Implementation Plans, engines which can emit more than 100 tons per year of NOx must now be equipped with Reasonably Available Control Technology (RACT) pollution control devices to reduce NOx emissions. In addition, owners are looking for ways to minimize permit fees and avoid major source monitoring expenses by adding control technology to attain minor source status. A new technology, plasma combustion control, has been demonstrated during the last year to help meet all current U.S. and Canadian environmental guidelines with significant capital and operating cost savings.