The U.S. Environmental Protection Agency is proposing to partially approve an updated Oregon State Implementation Plan that also covers the planned shutdown of the coal-fired Boardman power plant.
EPA said in a May 23 Federal Register notice that it is proposing to approve portions of a SIP revision submitted by the state of Oregon in December 2010 and supplemented in February 2011, as meeting the requirements of the Clean Air Act and federal regulations. In a previous action in July 2011, EPA approved portions of the December 2010 SIP submittal as meeting the requirements for interstate transport for visibility of a section of the CAA and certain requirements of the regional haze program including requirements for best available retrofit technology (BART).
The action in the May 23 Federal Register notice addresses the remaining requirements of the CAA and EPA’s rules that require states to prevent any future and remedy any existing anthropogenic impairment of visibility in mandatory Class I areas caused by emissions of air pollutants from numerous sources located over a wide geographic area (also referred to as the regional haze program). Written comments on the proposed approval are being taken until June 22.
EPA previously reviewed and approved Oregon’s BART determinations for all sources subject to BART in Oregon. BART was determined for one source, Portland General Electric’s coal-fired Boardman Electric Generating Unit (EGU), and Federally Enforceable Permit Limits (FEPLs) were established for four BART-eligible sources to reduce visibility impacts at any Class I area. These four sources are:
PGE Beaver EGU – To achieve the emission limits established in the Title V permit, the facility is using ultra-low sulfur diesel fuel (with no more than 0.0015% sulfur) in its oil-fired BART eligible units. The source must also use only ‘‘pipe line quality’’ natural gas in the gas-fueled PWEU1 unit.
Georgia Pacific Wauna Mill – To achieve the emission limits established in the Title V permit, the mill has reduced its SO2 emissions by: permanently reducing use of fuel oil in the Power Boiler: discontinuing the use of fuel oil in the Lime Kiln until the Non-Condensable Gas Incinerator (NCGI) unit is shut down; and limiting pulp production rate to 1,030 tons per day until the NCGI unit is shut down, at which time the production rate will be limited to 1,350 tons per day.
International Paper, Springfield – To achieve the emission limits established in its Title V permit, the plant has reduced its emissions of SO2, NOX, and particulate matter (PM) by accepting limits on fuel usage and operation, and meeting a combined SO2 and NOX daily emission limit based on a plant fuel use specific formula. The permit requires this facility to include the package boiler (EU–150B) emissions when demonstrating compliance with condition 210 of the permit until the source submits a notice of completion of No. 4 recovery boiler mud and steam drum replacement.
Amalgamated Sugar Plant, Nyssa – This plant is currently shut down and has no identified date to resume operations. In the event it does resume operation in the future, Oregon regulators will require that this facility be subject to a FEPL in its Title V permit, or conduct a BART analysis and install BART prior to resuming operation.
Boardman gets retrofitted, then eventually closed
Boardman is a coal-fired power plant capable of producing about 617 MW of electricity. Oregon regulators determined BART for this source to be 0.23 lbs/mmBtu for NOX based on a new low-NOX burner/modified overfire air system, 0.40 lbs/mmBtu for SO2 based on initial operational efficiency of a new Direct Sorbent Injection System, and 0.40 lb/mmBtu for PM, based on the current PM emission limit for the existing electrostatic precipitation system. The BART rule for this facility requires that the Foster Wheeler boiler at the facility permanently cease burning coal by no later than Dec. 31, 2020, EPA noted.
Portland General Electric, a part owner of Boardman and its operator, in 2010 made a deal with regulators and environmentalists, under something called the Boardman 2020 plan, to retrofit the plant with new air controls and then to shut it by the end of 2020.
“New emissions controls at Boardman are expected to reduce nitrogen oxide emissions by about 50 percent and permitted levels of sulfur dioxide emissions by 75 percent,” said the Portland General Electric website. “State rules also require new controls to reduce the plant’s mercury emissions by 90 percent. All coal-related emissions from the Boardman facility will be reduced to zero with the end of coal-fired operations in 2020. The combined capital cost of the required controls is currently estimated at about $60 million.”
The new controls include:
- New low-NOx burners and modified overfire air ports to comply with BART standards for NOx. These were installed in the spring of 2011.
- An activated carbon injection system to allow capture and removal of mercury from the plant’s emissions. This system was also installed in the spring of 2011.
- A separate dry sorbent injection system to comply with BART standards for SO2. PGE also expects to switch to a coal supply that contains less sulfur.