The U.S. Environmental Protection Agency on March 26 published a final approval of the regional haze state implementation plan (SIP) for the state of Nevada that will impact coal-fired facilities in the state, including the Reid Gardner Generating Station (RGGS).
The regional haze rule requires states to prevent any future and remedy any existing man-made impairment of visibility in mandatory Class I areas. EPA proposed to approve all parts of Nevada’s SIP revisions in June 2011. This final approval applies to all aspects of Nevada’s SIP except for that portion of Nevada’s determination regarding the Best Available Retrofit Technology (BART) to reduce NOx emissions at the plant. EPA said in a March 26 Federal Register notice that it will take action on BART for NOx at this plant in a future notice.
Following EPA’s review of the public comments on the NOx issue for RGGS issue, the agency said it performed additional analysis of Nevada’s NOx BART determination for RGGS. “As a result, we no longer consider the currently available information to be sufficient for us to take final action on the Nevada Division of Environmental Protection’s (NDEP’s) determination that rotating overfire air (ROFA) with Rotamix (a form of selective non-catalytic reduction or SNCR) is the NOx control technology that represents BART,” said EPA.
RGGS consists of four coal-fired boilers, three of which are BART-eligible units with generating capacity of 100 MW each. A fourth unit (250 MW) is not BART-eligible. NV Energy, the owner of RGGS, performed a BART analysis for the three BART-eligible units and submitted the results of its analysis to NDEP. In its BART analysis, NV Energy considered several NOx control technologies and evaluated the cost of compliance and visibility improvement associated with each technology. In preparing the SIP, NDEP relied on certain aspects of Nevada Energy’s analysis while performing updated analyses for other aspects.
When considering the cost and cost effectiveness of compliance, NDEP developed its own emission reduction estimates for the various NOx control technologies, but used NV Energy’s estimates of total capital and annual costs. In its submittal to NDEP, NV Energy determined that low NOx burners (LNB) with OFA (overfire air) were BART for NOx. In preparing the SIP, NDEP determined that a more stringent control technology, ROFA with Rotamix, was BART for NOx. NDEP eliminated even more stringent control options, such as selective catalytic reduction (SCR) with LNB and OFA, on the grounds that these systems would cost too much for the visibility improvements they would bring.
EPA said it received several comments alleging flaws in NDEP’s analysis and stating that SCR should be BART for NOx at RGGS. These commenters criticized NDEP’s development of the cost-effectiveness values and expected visibility improvement attributable to the more stringent SCR-based control option.
NV Energy (NYSE:NVE) is the parent Nevada Power Co. d/b/a NV Energy. In its Feb. 24 annual Form 10-K report, parent NV Energy described the regional haze process. In 2008, the state of Nevada began its BART rule development and the proposed SIP to implement the BART requirements was released in the first quarter 2009. As presented in the SIP, the impacted BART units for the company are RGGS Units 1-3; Ft. Churchill Units 1-2; and Tracy Units 1-3.
“On June 9, 2011, the EPA published in the Federal Register its draft proposal to approve Nevada’s Regional Haze Plan as meeting the requirements of the Clean Air Act,” said the Form 10-K. “However, in announcing its final approval in December 2011, the EPA opted to take no action specifically on the BART determination for nitrogen oxide (NOx) at the Reid Gardner Generating Station, stating that it intends to propose action on those units at a later date and take public comment in the future. The EPA’s final approval did include the state’s proposed BART determinations for SO2 and particulate matter for Reid Gardner Generating Station, as well as the BART controls proposed for all of the other NVE affected units.”
The Form 10-K added: “Given the final EPA action in December, NVE is implementing the approved portions of the rule which will require compliance by January 1, 2015. NVE intends to retire Tracy Generating Station Units 1 and 2 and install retrofit controls on Tracy Generating Station Unit 3 and Ft. Churchill Generating Station Units 1 and 2. A cost estimate is currently being prepared based on specific engineering specifications and designs. It is anticipated that the EPA will request additional information prior to making the final determination on the Reid Gardner Generating Station NOx controls. However, until the final determination is made, it is impossible to predict the effect the ruling may have on Reid Gardner Generating Station’s generating units.”
The affected Tracy and Ft. Churchill units are fired by gas and oil. The Form 10-K noted that the gas-fired Sunrise Units 1-2 were retired at the end of 2011.