Announcements
TRC meeting #3 scheduled for July 29th
Technical Noise Workshop scheduled for July 29th
Meeting Summary for Public Workshop #2 - coming soon
Contact Information
Stan Shepherd
Airport Noise Programs Manager
Port of Seattle
P.O. Box 68727
Seattle, WA 98168
Rob Adams
Part 150 Project Manager
Landrum and Brown
11279 Cornell Park Dr.
Cincinnati, OH 45242
Frequently Asked Questions
- What is a Part 150 Study?
- Why prepare a Part 150 Study?
- What will the study include?
- How long will the Part 150 Study take to complete?
- What is the purpose of noise monitoring?
- What is the Integrated Noise Model?
- What is DNL?
- What are Noise Exposure Maps (NEM)?
- How do I comment on the study?
- Since the third runway opened, have operations on the runway been more frequent than anticipated?
- Under what set of circumstances are aircraft expected to use the third runway?
- Can Sea-Tac Airport restrict operations on its runways?
- Where does the Port of Seattle receive funding for noise mitigation projects?
- What type of noise mitigation projects can the Port of Seattle spend funds on?
- Can the Port of Seattle use tax levy funds for noise mitigation projects?
- What noise mitigation efforts has the Port already undertaken?
- What set of circumstances complicates efforts to reduce noise for residents around Sea-Tac Airport?
- Is Sea-Tac Airport getting quieter due to improved aircraft technology?
- What results can the communities around Sea-Tac Airport expect from the new Part 150 process once it is complete?
- What are some of the positive impacts a major international airport like Sea-Tac has on the Puget Sound region?
- How can I get involved with the Part 150 Study as it progresses and where can I find information?
What is a Part 150 Study?
Part 150 is a section of the Federal Aviation Regulations (FAR) that sets forth rules and guidelines for airports desiring to undertake airport noise compatibility planning. Through Part 150, the FAA established regulations governing the technical aspects of aircraft noise analysis and the public participation process for airports choosing to prepare airport noise compatibility plans.
The Part 150 planning process involves the methods and procedures an airport operator must follow when developing a Noise Compatibility Plan (NCP). A Part 150 Study involves six major steps:
- Identification of airport noise and land use issues and problems;
- Definition of current and future noise exposure patterns;
- Evaluation of alternative measures for abating noise (e.g., changing aircraft flight paths), mitigating the impact of noise (e.g., sound insulation), and managing local land uses (e.g., airport-compatible zoning);
- Development of a NCP;
- Development of an implementation and monitoring plan; and
- FAA review and approval of the recommended NCP, including the analysis of alternatives, the compatibility plan, and the implementation and monitoring plan.
The Part 150 Study process is designed to identify noise incompatibilities surrounding an airport, and to recommend measures to both correct existing incompatibilities and to prevent future incompatibilities. For Part 150 Study purposes, noise incompatibilities are generally defined as residences or public use noise-sensitive facilities (libraries, churches, schools, nursing homes, and hospitals) within the 65 Day-Night Average Sound Level (DNL) noise contour.
Why prepare a Part 150 Study?
The purpose for conducting a Part 150 Study at an airport is to develop a balanced and cost-effective plan for reducing current noise impacts from an airport's operations, where practical, and to limit additional impacts in the future. By following the process, the airport operator is assured of the FAA's cooperation through the involvement of air traffic control professionals in the study and the FAA's review of the recommended Noise Compatibility Program (NCP). The decision to undertake noise compatibility planning is entirely voluntary on the part of the airport operator.
An airport with an FAA-approved NCP also becomes eligible for funding assistance for the implementation of measures in the NCP.
Among the general goals and objectives addressed by a Part 150 Study are the following:
- To reduce, where feasible, existing and forecasted noise levels over existing noise-sensitive land uses;
- To reduce new noise-sensitive developments near the airport;
- To mitigate, where feasible, adverse impacts in accordance with Federal guidelines;
- To provide mitigation measures that are sensitive to the needs of the community and its stability;
- To minimize the impact of mitigation measures on local tax bases; and
- To be consistent, where feasible, with local land use planning and development policies.
What will the study include?
The study will identify existing and future flight corridors, develop aircraft noise exposure maps for current and future conditions, evaluate air traffic control procedures that could be implemented to reduce noise exposure over residential areas, consider land use controls that could be established to reduce future incompatible land uses from being developed within high noise areas, and evaluate means to mitigate noise impacts within high noise exposure areas.
How long will the Part 150 Study take to complete?
The Port of Seattle began early coordination of the Part 150 study in November 2009, and the consultant team began work in January 2010. The study is scheduled for completion by the end of 2011. Implementation of the study recommendations will be based on review and approval of the reports by the Port of Seattle and the FAA. The review period by the FAA is typically 6-9 months.
What is the purpose of noise monitoring?
Field measurements from the airport's permanent monitoring system will be collected for use in the study. The measurements will be compared with pre-existing database information related to aircraft noise level and performance characteristics in FAA's Integrated Noise Model. The information collected during the measurement program will include acoustical output, as measured at known locations, as well as flight trajectory data (the aircraft's three-dimensional location) relative to the noise measurement site. This information will be used to ensure that the input data into the Integrated Noise Model is as accurate as possible.
What is the Integrated Noise Model?
The FAA has developed the Integrated Noise Model (INM) for evaluating aircraft noise impacts in the vicinity of airports. The INM has been the FAA's standard tool since 1978 for determining the predicted noise exposure in the vicinity of airports. The FAA requires the use of INM to develop noise exposure contours in FAR Part 150 Noise and Land Use Compatibility Studies.
The INM utilizes flight track information, aircraft fleet mix, standard and user defined aircraft profiles and terrain as inputs. The INM produces noise exposure contours that are used for land use compatibility maps. The INM includes built-in tools for comparing contours and utilities that facilitate easy export to commercial Geographic Information Systems. The INM also calculates noise levels at specific sites such as hospitals, schools or other noise sensitive locations.
What is DNL?
The Day-Night Average Sound Level metric describes the total noise exposure during a given period. However, DNL, by definition, can only be applied to a 24-hour period. In computing DNL, an extra weight of 10 dB is assigned to any sound levels occurring between the hours of 10:00 p.m. and 7:00 a.m. This is intended to account for the greater annoyance that nighttime noise is presumed to cause for most people. This extra weight treats one nighttime noise event as equivalent to 10 daytime events of the same magnitude.
What are Noise Exposure Maps (NEM)?
NEMs identify the noise exposure of the current operating conditions, and projected future conditions. Included within this analysis will be the operating conditions currently taking place at the airport including existing departure and arrival procedures, daytime and nighttime activity, touch and go operations and helicopter activity.
How do I comment on the study?
To submit a comment or question to the Part 150 Team, visit the Contact page of this website.
Since the third runway opened, have operations on the runway been more frequent than anticipated?
The third runway (16R/34L) opened officially on November 20, 2008. From March 30, 2009 to September 30, 2009, Sea-Tac's longest runway (16L/34R) was closed for a comprehensive reconstruction that increased operations on the center runway (16C/34C) and third runway.
When all three runways are operating as they were from November 20 to March 29 and from October 1 to the present, overall use of the third runway is actually less than the level predicted in the 1997 Supplemental Environmental Impact Statement (EIS) for Sea-Tac's Master Plan. The Supplemental EIS projected the number of operations on all of the airport's runways, including the third runway, in the year 2010. The latest runway use percentages, which are updated every two weeks, are available on the Port's Runway Statistics Web page - http://www.portseattle.org/community/environment/runwaystatistics.shtml
Under what set of circumstances are aircraft expected to use the third runway?
During lower visibility conditions, arriving aircraft are directed onto the third runway and the longest, easternmost runway, allowing Sea-Tac to accept two streams of traffic with adequate separation. Prior to opening the third runway, Sea-Tac could use only one of its two runways for arrivals during lower visibility conditions. Directing all arriving aircraft onto one runway slowed things down and caused significant delays.
The third runway also is used during peak traffic periods when multiple aircraft are scheduled to arrive in the same time period. During these peaks, the third runway is used along with the easternmost runway for arrivals in order to help reduce delays regardless of the weather.
It is important to note that the Federal Aviation Administration (FAA) has the responsibility for managing air traffic at Sea-Tac, and, at any time they have the authority to change the way they use the runways to efficiently manage air traffic and ensure safety.
Can Sea-Tac Airport restrict operations on its runways?
No. The FAA is the only entity that can manage aircraft runway operations or aircraft in flight at Sea-Tac Airport. Furthermore, as a recipient of grant funds from the FAA, the Port of Seattle, operator of Sea-Tac Airport, must abide by specific FAA-imposed obligations and conditions. One of these is that Sea-Tac will not restrict or limit airfield access based on noise. This means, for example, that a Port-imposed nighttime curfew preventing aircraft from landing on or departing from the third runway would violate FAA requirements.
Some airports, like John Wayne Airport in Orange County, still have airfield access limitations, such as curfews on commercial aircraft at night that were instituted prior to the 1990 federal Airport Noise & Capacity Act (ANCA). Except for those that were implemented prior to November 1990, ANCA prohibits regulations or amendments to existing restrictions that limit airfield access. ANCA also provides for the complete phase out of all noisy Stage 1 and Stage 2 aircraft over 75,000 pounds at all airports, including commercial airports like Sea-Tac, by 2000. Sea-Tac phased out Stage 1 and Stage 2 aircraft over 75,000 pounds before the federal deadline.
Where does the Port of Seattle receive funding for noise mitigation projects?
When noise mitigation programs are approved by the FAA through a formal Part 150 Study, those programs then become eligible to receive FAA Grant funding of up to 80%. The remainder of the funding comes from revenues generated at the airport (parking fees, landing fees, etc.).
What type of noise mitigation projects can the Port of Seattle spend funds on?
Any noise reduction related project approved by the Port Commission and the FAA through a Part 150 Noise Study that demonstrates how it will have a measureable impact on noise can qualify for FAA funding and for Port of Seattle funding. For example, insulation projects inside the 65 Day Night Level (DNL) Contour, the FAA-established noise boundary that determines insulation eligibility, would qualify. (DNL is a 24-hour average noise level with a 10-decibel penalty for nighttime noise events.) Conversely, proposed insulation projects far outside the 65 DNL would not qualify. FAA funding sources come with a number of stipulations and conditions that the Port agrees to when accepting funds. Additionally, the same FAA conditions would prevent the Port from using the revenues it generates at the airport (parking fees, landing fees, etc.) for projects that are unable to demonstrate a measureable community impact on noise.
Qualifying for FAA grants is the first step. Other steps include actually obtaining the grants from the FAA and receiving Port Commission approval authorizing the use of airport funds. The Port has long been successful at securing FAA grants and implementing noise mitigation projects in the surrounding communities.
Can the Port of Seattle use tax levy funds for noise mitigation projects?
Other than funds allocated to the Highline School District for Aviation High School ($15 million) and for the insulation and associated repair of schools (a total Port of Seattle/FAA pledge of $100 million), the Port Commission has not authorized using the Port tax levy money for projects at the airport, because the airport is exclusively supported by user fees.
What noise mitigation efforts has the Port already undertaken?
Since 1976, the Port of Seattle has acquired approximately 1,466 single-family homes and five mobile home parks, containing nearly 260 units. The Port also provided relocation benefits to all the residents, enabling them to relocate to quieter neighborhoods. In addition, the Port insulated more than 9,300 homes and five condominium complexes with a combined total of 236 units. Twelve of 22 planned Highline Community College buildings were insulated and, in partnership with the FAA, the Port has so far contributed $50 million (from a total Port of Seattle/FAA pledge of $100 million) for sound insulation and related improvements at schools within the Highline School District.
Sea-Tac Airport also implemented a number of noise abatement procedures to reduce the noise produced by aircraft while on the ground, during takeoffs and landings, and during flights over populated areas. These include Sea-Tac's noise abatement flight procedures, engine maintenance run-up guidelines and the Fly Quiet Incentive Program that recognizes the quietest airlines operating at Sea-Tac each year. Because of its comprehensive noise abatement efforts and extensive sound insulation programs, Sea-Tac is recognized today as having one of the most complete and robust noise reduction programs in the nation.
What set of circumstances complicates efforts to reduce noise for residents around Sea-Tac Airport?
Three things make noise reduction efforts a challenge. First, Sea-Tac Airport is situated in a highly populated area that has steadily grown around the airport. Second, the north-south configuration of Sea-Tac's three runways means that flights over the neighborhoods north and south of the Airport are unavoidable. The orientation of runways is based predominantly on wind direction because aircraft take off and land into the wind. And third, Sea-Tac Airport is the main international airport in the region and the state and is a vital part of the national transportation system. Rules and restrictions to reduce noise must be considered in the context of federal laws, air traffic procedures and with the involvement of all parties including the Port, the FAA, the community and the airlines.
Is Sea-Tac Airport getting quieter due to improved aircraft technology?
One major contributing factor to reduced noise contours at Sea-Tac is that airlines continue to retire older, noisier aircraft from their fleets. For example, in 2008 Alaska Airlines retired its noisier MD-80 fleet and replaced them with newer, quieter Boeing 737-800 aircraft. The transition by the airlines to a more modern, fuel-efficient fleet continues to decrease Sea-Tac's noise footprint.
What results can the communities around Sea-Tac Airport expect from the new Part 150 process once it is complete?
The Part 150 Study is a planning effort designed to address and mitigate the effects of aircraft noise within the Airport communities. In the last Part 150 Noise Study, which was completed in 2002, the Port projected what the noise impacts would be once the third runway opened and then implemented a comprehensive noise mitigation program including extensive insulation and acquisition projects in preparation for the runway's opening.
The current Part 150 Study, Sea-Tac's fourth, began in November 2009. As part of their work, the consultants will first develop new noise maps showing how the airport's overall noise affects the community now and in five years. Then, they will conduct a wide-ranging review of all of the airport's noise reduction efforts and an evaluation of new ways to improve upon the efforts. The public will help identify and shape the noise reduction recommendations that ultimately will be included in the Part 150 Study. If the study identifies areas of 65 DNL that were not captured in the previous projections, then more noise mitigation for those affected will be considered. The Port is committed to a thorough and accessible public process throughout the Part 150 Study that will ensure there are multiple avenues for involvement and public comment.
What are some of the positive impacts a major international airport like Sea-Tac has on the Puget Sound region?
Sea-Tac Airport's activities and facilities are directly responsible for more than 89,000 jobs in the Puget Sound region. Roughly 15,000 of those jobs are directly at Sea-Tac Airport with many of those jobs held by residents living in the communities around the airport. The 89,000 jobs equal $2.2 billion in direct earnings. The airport generates over $13 billion in revenue for businesses who provide services to the airport, including airport tenants, and produces $412.4 million each year in state and local tax dollars.
In 2009, more than 31 million passengers traveled through Sea-Tac which equates to over 80,000 daily travelers. Roughly 72% of those travelers were beginning or ending their trip in Seattle, meaning they simply weren't transfering from one flight or another. They are business travelers coming to Seattle for meetings. They are local residents bound for vacations across the globe. They are parents and grandparents from across the country coming to visit their children and grandchildren. And, each of these travelers shares a common appreciation for Sea-Tac Airport and how the airport connects them with the world.
How can I get involved with the Part 150 Study as it progresses and where can I find information?
A series of public workshops will be held at key milestones during the Part 150 Study. Open to all, each workshop will include smaller breakout sessions, where members of the public can provide input, ask questions and offer recommendations in a more personal setting. To keep up-to-date throughout the Part 150 process and learn when the next workshop will be held, sign up to receive email updates - www.portseattle.org/community/environment/noise.shtml
A dedicated Part 150 Study website has been established as the single location for all documentation connected to the study. - www.airportsites.net\sea-part150