CHAPTER 1 BACKGROUND AND PROPOSED ACTION

CHAPTER 1 BACKGROUND AND PROPOSED ACTION 1.0 INTRODUCTION An Environmental Assessment (EA) evaluates the effects of a proposed Federal action on the surrounding environment and is prepared in compliance with the National Environmental Policy Act (NEPA). Federal Aviation Administration (FAA) Order 1050.1E, Environmental Impacts: Policies and Procedures, and FAA Order 5050.4B, Airport Environmental Handbook describe Federal airport and aviation actions that trigger the requirement for EAs and Environmental Impact Statements (EISs). Both FAA Orders also provide detailed guidance on the preparation of airport and aviation environmental studies. This EA identifies the potential environmental impacts associated with the proposed development action explained herein. It also demonstrates how identified impacts can be eliminated or mitigated, and provides the context for public involvement and comment. This EA assesses the impact categories required by FAA Orders 1050.1E and 5050.4B in relationship to the proposed project. The Town of Stevensville, Montana is proposing improvements to existing Runway 12-30 and partial parallel Taxiway-A at the Stevensville Airport (32S) as outlined in Section 2.0. This development proposal requires FAA approval of grant applications prior to consideration for Federal funding. The proposed project is expected to be completed within two to three years following the outcome of the EA, and contingent upon funding. 1.1 BACKGROUND AND EXISTING FACILITIES The Stevensville Airport, serving the Town of Stevensville and Ravalli County, is located in western Montana, three (3) miles northeast of the Town of Stevensville, and approximately thirty (30) miles south of the City of Missoula, Montana. Access to the airport is provided from Missoula via State Highway 93 to Stevensville. The airport is situated in a valley with significant mountainous terrain to the east and west. The property immediately surrounding the airport is used primarily for agricultural purposes interspersed with low density rural residential development. The Stevensville Airport s elevation is 3,614 feet Mean Sea Level (MSL) with the mean maximum temperature of the warmest month of 84.5 F. The Stevensville Airport has a total area of 188.61 acres, of which 176.3 acres are owned in fee by the Town of Stevensville, and the remaining 12.31 acres are controlled by easement. Current airport facilities include a 3,800-foot x 60-foot asphalt runway (Runway 12-30), a 35-foot wide taxiway (Taxiway-A) that is parallel to Runway-30, a jug handle turn around taxiway for Page 1

Runway-12, a 30-foot wide midfield connector taxiway between Runway 12-30 and the aircraft parking ramps, a 238-foot x 380-foot asphalt apron (west ramp), a 238-foot x 248-foot asphalt apron (east ramp), several 25-foot wide, and 35-foot wide taxilanes for hangar access, lighted wind sock and segmented circle, and rotating beacon. Runway 12-30, a visual approach runway, has a medium intensity runway edge lighting system (MIRLS) and a Precision Approach Path Indicator (PAPI) on the Runway 12 end for navigation. The design strength of the Runway 12-30 asphalt pavement is 12,500 pounds single wheel loading. The pavement strength at the Stevensville Airport correlates to small aircraft and is consistent to the aircraft that are currently using the airport. The current runway profile is sloped at the FAA s maximum allowable gradient for a runway. This slope is a constant downhill 2 percent slope from the southern end (Runway-30) to the northern end (Runway-12). Prevailing winds typically force aircraft to use Runway-30 for approach and landing operations. The fact that the runway is sloping away from an approaching aircraft (when landing on Runway-30), naturally causes an aircraft to use more runway length when landing then it would at a similar sized airport. The airport is used for business, governmental, emergency medical, and personal use. Ravalli County is in the heart of the Bitterroot National Forest, and the Stevensville Airport is heavily used for forest management purposes (aerial survey and firefighting operations) as well as for recreational purposes. The Airport Layout Plan provides a graphic presentation of the existing airport facilities and recommended future facilities (Appendix A Airport Layout Plan and Property Exhibit A Drawings). The plan depicts the runway and parallel taxiway projects as future projects. 1.2 AIRPORT OPERATIONAL FORECASTS Stevensville Airport is located in the busiest aviation corridor in the state of Montana; Kalispell to Hamilton. This corridor includes commercial airports Glacier Park International and Missoula International and General Aviation (GA) airports Kalispell City, Polson, Ronan, St. Ignatius, Stevensville and Hamilton. Stevensville Airport is located approximately midway between Missoula International Airport and Ravalli County Airport. It is the closest public airport to Misoula International Airport (MSO). Stevensville Airport, therefore, has the potential to attract general aviation from MSO including operations resulting from poor weather in Missoula, flight training operations originating out of Missoula and based aircraft relocation from GA overflow. The Town of Stevensville is less than 30 miles from Missoula and the northern portion of the Bitterroot Valley has become a bedroom community of Missoula. The close proximity of Missoula influences many aspects of the Bitterroot Valley economy including population growth and levels of employment. Page 2

Population statistics and forecasts for Ravalli County and Missoula County were developed from Regional Economic Models, Inc. provided by the Montana Department of Commerce and are summarized in Table 1-2. Table 1-2: Population Statistics and Projections Ravalli County Missoula County Year Population Percent Change Population Percent Change 1990 25,068 79,080 2000 36,301 44.8% 96,178 21.6% 2010 40,343 11.1% 109,443 13.8% 2020 42,050 4.2% 123,553 12.9% 2030 44,691 6.3% 134,085 8.5% Source: eremi - a product of Regional Economic Models, Inc. (www.remi.com) - Released April 2013 Compiled by the Census & Economic Information Center, MT Dept. of Commerce (www.ceic.mt.gov) 1.3 BASED AIRCRAFT FORECASTS Historically, the 2013 Terminal Area Forecast (TAF) shows the number of based aircraft growing from 37 in 1990 to a peak of 86 in 2007, dropping to 78 in 2008 and remaining constant at 78 through 2013. This represents an average historic growth rate of 2.3 percent, or approximately two new aircraft per year. The TAF forecasts that the 78 based aircraft at Stevensville in 2013 will remain constant through 2040. However, the TAF is a nationally standardized forecast that often underestimates growth at small GA airports. As a national forecast, it does not incorporate local growth factors, but uses an average growth rate derived from forecast national operations. The TAF typically shows flat growth forecast at all but Montana s primary airports. On the basis of historical growth and local indicators for robust future growth, it is expected that the number of based aircraft will not remain flat at Stevensville, as forecast by the TAF, but should continue to increase by approximately 2 to 3 new aircraft per year, equivalent to an annual growth rate of approximately 2.5 percent. This is consistent with historical growth and reasonable considering local growth factors including the following: The Town of Stevensville recently completed a taxilane extension project that opens more developable hangar lots due to recent inquiries for more hangar space. In January 2014, a hangar capable of housing Category B, Design Group II aircraft was constructed, and in the spring/summer 2015, another similar sized hangar is scheduled to begin construction. Page 3

A t-hangar configuration capable of housing 8 aircraft completed construction in the fall of 2014 further justifying that aviation use at the Stevensville Airport is on the rise. A summary of the TAF based aircraft forecast and a based aircraft forecast with a 2.5% growth rate is provided in Table 1-3 below. Table 1-3: Based Aircraft Forecasts Historic Forecast Year 2013 TAF 2.5% Growth Rate 1990 37 37 1995 48 48 2000 48 48 2005 58 58 2010 78 78 2013 78 78 2015 78 79 2020 78 83 2025 78 84 2030 78 88 1.4 OPERATIONS FORECAST The Terminal Area Forecast (TAF) separates aircraft operations into several categories including itinerant air carrier, itinerant air taxi, itinerant GA, itinerant military, local GA and local military. Table 1-4 below, summarizes the general aviation operations forecast in the 2013 TAF. There were no operations from air carrier or military aircraft forecast at Stevensville Airport during the planning period. Page 4

Table 1-4: Operations Forecast FAA Terminal Area Forecast Year Itinerant Air Itinerant GA Local GA Total Taxi Historic 1990 150 1,800 4,800 6,750 1995 1,000 2,500 6,500 10,000 2000 1,000 2,500 6,700 10,200 2005 1,100 3,000 7,300 11,400 2010 1,400 3,600 8,500 13,500 2013 1,400 3,600 8,500 13,500 Forecast 2015 1,400 3,600 8,500 13,500 2020 1,400 3,600 8,500 13,500 2025 1,400 3,600 8,500 13,500 2030 1,400 3,600 8,500 13,500 The flat growth rate shown in the TAF for aircraft operations at Stevensville Airport is not considered reasonable due to the following factors: Ravalli County has been, and is projected to continue as one of the fastest growing counties in Montana with an annual growth rate exceeding 3 percent; The Stevensville Census District is projected to grow at an even greater rate. Urban sprawl from the City of Missoula may further stimulate growth in this area; Stevensville Airport is located in the busiest aviation corridor in the state of Montana; Kalispell to Hamilton; and has the potential to attract itinerant operations resulting from heavy commercial air traffic and poor weather VFR conditions in Missoula; Stevensville Airport will likely continue to attract small, single and twin-engine aircraft from the region. Itinerant GA operations are likely to grow in the future at the Stevensville Airport in conjunction with population and economic growth in both Ravalli and Missoula Counties. As noted, Stevensville Airport is located in the busiest aviation corridor in the State of Montana. In addition, many of the counties that fall within this corridor are experiencing significant growth. This regional growth is likely to spur an increase in aviation activity throughout the area, including Stevensville Airport. Historically, the 2013 Terminal Area Forecast (TAF) shows the number of itinerant GA operations growing from 1800 in 1990 to 3600 in 2013. This represents an average historic growth rate of 2.2 percent. On the basis of historical growth and indicators for robust future growth, it is expected that the number of itinerant GA operations will continue to increase by a similar annual growth rate. Page 5

Local GA operations are also anticipated to grow beyond what is forecast in the TAF. Historically, the 2013 Terminal Area Forecast (TAF) shows the number of local GA operations growing from 4800 in 1990 to 8500 in 2013. This represents an average historic growth rate of 1.9 percent. On the basis of historical growth and indicators for robust future growth, it is expected that the number of local GA operations will continue to increase by a similar annual growth rate. Table 1-5 below depicts an operations forecast for Stevensville Airport that accounts for reasonable anticipated growth in itinerant and local GA Operations. Table 1-5: Stevensville Airport Operations Forecast Year Itinerant Air Itinerant GA Local GA Total Taxi Historic 1990 150 1,800 4,800 6,750 1995 1,000 2,500 6,500 10,000 2000 1,000 2,500 6,700 10,200 2005 1,100 3,000 7,300 11,400 2010 1,400 3,600 8,500 13,500 2013 1,400 3,600 8,500 13,500 Forecast 2015 1,400 3,679 8,662 13,741 2020 1,400 4,192 9,697 15,289 2025 1,400 4,674 10,654 16,728 2030 1,400 5,212 11,705 18,317 1.5 RUNWAY DESIGN CODE The Runway Design Code (RDC) is a coding system developed by the FAA to correlate runway design criteria with the operational and physical characteristics of the airplane types that regularly use a particular airport. The critical aircraft, or grouping of aircraft, are generally the largest, most demanding types that conduct at least 500 operations per year at the airport. In cases where the critical aircraft weigh less than 60,000 lbs., a classification of aircraft is used rather than a specific individual aircraft model. The RDC for each particular airport is determined based on two characteristics of the critical aircraft: the approach speed to the runway and the wingspan of the aircraft. The first component, designated by letter A through E, is the critical aircraft s Approach Category. This is determined by the approach speed of the aircraft to the runway: Category A: Approach speed less than 91 knots. Category B: Approach speed 91 knots or more, but less than 121 knots. Category C: Approach speed 121 knots or more, but less than 141 knots. Category D: Approach speed 141 knots or more, but less than 166 knots. Page 6

Category E: Approach speed 166 knots or more. The second component, designated by Roman numeral I through VI, is the critical aircraft s Design Group. This is determined by the wingspan of the aircraft: Group I: Wingspan less than 49-feet. Group II: Wingspan 49-feet or more, but less than 79-feet. Group III: Wingspan 79-feet or more, but less than 118-feet. Group IV: Wingspan 118-feet or more, but less than 171-feet. Group V: Wingspan 171-feet or more, but less than 214-feet. Group VI: Wingspan 214-feet or more, but less than 261-feet. The FAA has also established categories for aircraft based on their certificated Maximum Takeoff Weights (MTOW), which are determined by each specific aircraft s manufacturer. Small Aircraft are those with MTOWs of 12,500 lbs. or less. Large Aircraft are those with MTOWs greater than 12,500 lbs. The FAA approved 2010 Master Plan and Airport Layout Plan confirmed that the current critical aircraft category (and RDC) for the Stevensville Airport is Category B, Design Group I, Small Aircraft. As noted above, aircraft in Category B have approach speeds of 91 knots, but less than 121 knots. The following excerpts from the Master Plan illustrate that an upgrade to RDC Category B, Design Group II Standards was anticipated. (Note: In September, 2012 the FAA released a significant update to its Airport Design Advisory Circular. The update, AC150/5300-13a, changed the Airport Reference Code (ARC) terminology to Runway Design Code (RDC).) Stevensville Airport is presently the fourth largest general aviation airport in Montana (lagging behind only Laurel, Ravalli County, and Glasgow Airports); but potentially the fastest growing airport in the State. The Stevensville Airport is servicing primarily small (less than 12,500 lbs) aircraft typical of the Cessna 170 and 180 Series. The critical aircraft is currently consistent with the criteria for [RDC] Category B, Design Group I aircraft. However, it won t be long before there are sufficient operations from larger aircraft to warrant the upgrade to [RDC] Category B, Design Group II standards. The sponsor should establish planning and development goals for Stevensville Airport which target small aircraft users typical of [RDC] Category B, Design Group I, while at the same time making every effort to protect for the necessary improvements which would allow for a future upgrade to [RDC] Category B, Design Group II. It should be noted that, at the time the Master Plan was prepared, the FAA did not provide separate design standards for Category B, Design Group II runways serving large aircraft and Page 7

those serving small aircraft. A recent change to FAA Advisory Circular 150/5300-13A (Change 1) revised design standards for Category B, Design Group II to distinguish between runways designed for small (less than 12,500 lbs) and large (greater than 12,500 lbs) aircraft. While it is not possible to obtain a precise operations count at an untowered airport, estimates can be made using reasonable assumptions. The forecast section of the Stevensville Master Plan was completed in 2008. At that time, it was estimated that approximately 230 annual operations at the airport were in the Category B, Design Group II category. This count was derived based on the following assumptions: A single based aircraft at Stevensville Airport completes approximately 125 operations per year. A single itinerant aircraft with frequent use of Stevensville Airport may conduct approximately 21 operations each year. In 2008, the airport had one based Category B, Design Group II aircraft (125 based operations) and an estimated 5 itinerant aircraft utilizing the airport on a regular basis (5 aircraft X 21 operations = 105 itinerant operations) for an estimated 230 total Category B, Design Group II operations. In discussions with the airport manager, airport usage by Category B, Design Group II aircraft has increased since 2008. In addition to the one Category B, Design Group II aircraft based at Stevensville year round, there are now two additional Category B, Design Group II aircraft which are stored at Stevensville on a seasonal basis, during the months of April through November. In addition, the airport received two orders for hangars which specifically requested doors suited to Design Group II aircraft. One of these hangars was completed in January of 2014 and the other is scheduled to break ground in the summer of 2015. The airport manager also estimated that 5 itinerant Category B, Design Group II aircraft utilize Stevensville on a seasonal basis, in addition to those noted in 2008. A conservative estimate of operations by Category B, Design Group II aircraft in the coming year is provided below. The estimate makes the conservative assumption that only one of the two new Design Group II hangars will house an actual Design Group II aircraft. Operations per aircraft for seasonal based and itinerant aircraft are conservatively assumed to be half those of year round based and itinerant aircraft. Page 8

Table 1-1: Category B, Design Group II Forecast Based Category B, Design Group II Aircraft (2008) Itinerant Category B, Design Group II Aircraft (2008) Additional Year-Round Based Category B, Design Group II Aircraft (2014) Additional Seasonal Based Category B, Design Group II Aircraft (2014) Additional Seasonal Itinerant Category B, Design Group II Aircraft (2014) Estimated Annual Category B, Design Group II, Operations Aircraft Operations per Annual Operations 1 125 125 5 21 105 1 125 125 2 62 124 5 10 50 529 This conservative estimate indicates that the number of Category B, Design Group II operations is currently at the threshold of 500 annual operations. Observations by airport management indicate that these operations are predominantly by aircraft weighing less than 12,500 lbs. and, therefore, fall into the small category. Therefore, the critical aircraft category for the Stevensville Airport is currently Category B, Design Group II, Small. 1.6 THE PROPOSED ACTION The Proposed Action includes the following major improvements: Widen RW 12-30 by 15-feet for a total width of 75 ; Extend RW-12 by 1,000-feet for a total runway length of 4,800 ; Reconstruct existing 60 x 3,800 pavement section for RW 12-30; Re-grade existing ground obstructions within the RSA and OFA; Replace the existing airfield electrical system; Replace the existing Medium Intensity Runway Lights; Replace the existing RW-12 PAPI; Install a new PAPI for RW-30; Install a new AWOS; Extend the partial length parallel TW-A to the new end of RW-12; Install new taxiway edge lighting system. Modify existing RNAV (GPS)-A procedure to reflect new runway end coordinates. The proposed lengthening and widening of Runway 12-30 and the extension of partial parallel Taxiway to the new RW-12 end reflect the outcome of an Airport Master Plan that was completed for the Stevensville Airport in 2010. The Master Plan included a process of defining facility requirements and analyzing alternatives. Reconstruction of the existing runway pavement was Page 9

identified in the plan as a safety related project. A detailed discussion of the alternatives reviewed in the Master Plan process and the rationale for selection of this alternative can be found in Chapter 3, Alternatives Considered. As part of the 2010 Master Plan, an Airport Layout Plan (ALP) reflecting the runway lengthening and widening was prepared and approved by FAA. The proposed action has been carried forward in subsequent updates to the ALP since 2010. Applicable drawings from the current ALP drawing set are included in Appendix A and B. The Proposed Action (Alternative A) will upgrade the airport to meet the design and safety requirements for the critical aircraft that is currently using the airport today (Category B, Design Group II, Small aircraft). Upgrade of the airport to Category B, Design Group II, large aircraft (12,500 lbs and over) standards, as identified in the Master Plan and ALP as the ultimate design group, is not included in the proposed action. Should future activity at the airport justify an upgrade to accommodate aircraft 12,500 lbs and over, a new environmental process will be required. Construction of the Proposed Action is projected to begin in 2015 contingent upon environmental approval and the availability of FAA and local funding. Page 10

Page 11 Figure 1-1: The Proposed Action