SITE INFORMATION AND CORRESPONDENCE

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5.16 WORKER HEALTH AND SAFETY - 50 to 1 for a horizontal distance of 10,000 feet from the nearest point on the nearest runway of each airport with its longest runway no more than 3,200 feet in length. - 25 to 1 for a horizontal distance of 5,000 feet from the nearest landing and takeoff area of a heliport. • Any highway,railroad, or other traverse way for mobile objects, of a height which,if adjusted by 17 feet for an Interstate,15 feet for local road, or 23 feet for a railroad,would exceed the standards in A or B of this section. • When requested by FAA. • Any construction on an airport or heliport. NCPA used the FAA Notice Criteria T0016 to determine whether the LEC met any of these FAR§77.13 requirements for notification of construction. The criteria tool indicated that the proposed stack would penetrate the 100 to 1 surface for Kingdon Airpark by approximately 70 feet,and thus notification is required through the filing of a 7460-1 Notice of Proposed Construction form to the Federal Aviation Administration(FAA). The required notice was filed on August 21,2008. A copy of the notice is provided in Appendix 5.6B. FAR§77.25 establishes imaginary surfaces surrounding civil airfields with specially prepared hard runway surfaces. Each of the surfaces varies in dimension and shape based on the category of aircraft operating at the airfield. The extent of these surfaces is shown in Figure 5.12-5. A review of FAR Part 77 imaginary surfaces for the LEC was conducted that considered imaginary surfaces identified in§77.25 Civil Airport Imaginary Surfaces. This analysis indicates the HRSG stack falls within the area of the Kingdon Airpark conical surface. At the location of the proposed LEC HRSG stack,the elevation of the conical surface is approximately 281 feet amsl. The LEC HRSG stack will be 150 feet tall with a base elevation of 8.5 feet, so the top of the HRSG stack will be well below the conical surface and no FAR Part 77 impacts would be expected as a result of the proposed project. 5.12.2.6.4 HRSG Visible Plume Analysis The potential for water vapor emissions to form visible plumes depends on the amount of water vapor in the exhaust gas,the temperature and volume of the exhaust gas, and the temperature and moisture content of the ambient air. There are various calculations and modeling procedures that can be used to predict the extent and frequency of visible plumes under site-specific ambient conditions. The applicant has provided the HRSG exhaust data and the ambient data that will allow the CEC staff to carry out their preferred modeling procedures and to predict the frequency and significance of visible plumes from the new HRSG stack (see Section 5.13,Visual Resources). Visible plumes occur under cold temperature/high humidity conditions,mainly during the winter months. The plume would tend to be larger when wind velocities are low because wind causes increased mixing,which limits vertical plume height potential and interferes with plume coherence. The wind frequency distribution data for the region (shown in Air Quality Appendix 5.113) indicate that low-speed winds are primarily from the north, 6 Available at https://oeaaa.faa.gov/oeaaa SAC/371322/082380003(LEC_5.12_TRAFFIC_AND_TRANSPORTATION.DOC) 5.12-25