Today’s filing, with the N.M. Environment Department, requests air permit changes to allow for the installation of either technology. Prior to a major environmental upgrade completed in 2009, the plant was emitting nitrogen oxides, or NOx, at a rate of 0.46 lbs. per mmBtu.[1] The plant’s current permit level is 0.30 lbs. per mmBtu and would be lowered to either 0.23 lbs. per mmBtu with the installation of SNCR and 0.05 lbs per mmBtu with the installation of SCR[2].
PNM believes the lower NOx limit for SCR, included in EPA’s recent final visibility rule on San Juan, is not required by federal regulation and arguably is the most stringent NOx limit imposed on a coal plant of its type in the United States. The San Juan plant today meets all ambient air quality and health-based emissions standards.
Due to the aggressive nature of EPA’s requirement that SCR be installed on all four of the plant’s units by September 2016, PNM is in the early stages of preparing to install SCR. In January, the company issued a request for proposals for that construction project.
PNM, New Mexico Gov. Susana Martinez and NMED have asked EPA to grant a stay of its decision during their appeal so that customers served by the San Juan plant – an estimated 2 million electric users in New Mexico, Colorado, Utah, Arizona and California – do not have to invest in a technology that the court could find is unnecessary.
According to PNM estimates, about $246 million of the total expected project cost will be spent through 2013 – a timeframe in which the matter could still be pending in court. As owner of 46 percent of the plant, PNM’s portion of these initial SCR costs total about $21.3 million through the end of this year and about $112.8 million through the end of 2013.
EPA has recently accepted SNCR as best available retrofit technology on coal plants in three other states -- Colorado, Montana and North Dakota – but has not yet considered New Mexico’s plan to install that same technology. Federal visibility rules give broad discretion to states to make decisions regarding how best to meet those rules within their own states. EPA is required by law to fully consider New Mexico’s plan.
