EPA is taking direct final action to approve three new optional test methods for measuring velocity and volumetric flow rate of flue gas from fossil fuel-fired boilers and turbines. These new methods allow the tester to account for velocity drop-off near the stack or duct wall and the yaw and pitch angles of flow. The primary users of the new methods will be owners and operators of utility units subject to the Acid Rain Program under title IV of the Clean Air Act, and certain large electric generating units and large non-electric generating units that may become subject to the nitrogen oxides (NO<INF>X</INF>) state implementation plan (SIP) call under Title I of the Clean Air Act, who must use an approved test method to periodically calibrate the flow rate monitors at these units. Flow rate data is used to determine the units' sulfur dioxide (SO<INF>2</INF>) and NO<INF>X</INF> mass emissions and heat inputs. The purpose of the Acid Rain Program and the NO<INF>X</INF> SIP call is to significantly reduce emissions from electric generating plants and other affected units in order to reduce the adverse health and environmental effects of acid deposition or ground level ozone resulting from these emissions. The sources affected by this action are primarily in the sector Fossil Fuel Electric Power Generation, North American Industrial Classification System (NAICS) code 221112, or are industrial boilers. The affected sources include U.S. industry establishments primarily engaged in operating fossil fuel powered electric power generation facilities. These facilities use fossil fuels, such as coal, oil, or gas, in boilers and combustion turbines to produce electric energy or steam. The electric energy produced in these establishments are provided to electric power transmission systems or to electric power distribution systems.