Town of Morrisville, NC November 2012 AIRPORT COMPATIBILITY AND RESIDENTIAL LAND USES

 Background and Context  Recent Trends  Observations and Recommendations OVERVIEW

BACKGROUND AND CONTEXT

 Primary Areas of Concern:  Safety  Restrictions on uses in crash zones and critical runway areas  Consequences: very severe (catastrophic event)  Obstruction  Height and location restrictions  Consequences: operational restrictions for aircraft  Noise  Limitations on uses in impacted areas  Extent varies  voluntary limitations  local land use policies and regulations  court ordered  Consequences: complaints, nuisance lawsuits, public opposition to airport projects, operational limitations (rare) AIRPORT COMPATIBILITY DEFINED

 FAA Does Not Have Land Use Authority  Part 150 Airport Noise Compatibility Program Regulations recommend compatibility measures but up to local entities to enact  Federal funding may not be used to remediate noise impacts for incompatible development that was constructed after 1998  Background Noise Levels Greatly Affect the Impacts of Aircraft Noise  Aircraft noise at a given level is more problematic in communities with low ambient noise levels than in urban settings KEY ISSUES AND CONSIDERATIONS

 65 LDN is most common threshold for residential compatibility – first enacted in 1970’s based on:  Annoyance  Speech interference  Sleep disturbance  Complaints  65 DNL reflected a compromise between what was environmentally desirable and technically feasible at the time  Aircraft now quieter  Older generation aircraft db louder  Noise contours were much larger KEY ISSUES AND CONSIDERATIONS

 Noise Contours (LDN or DNEL) represent weighted average levels, not individual occurrences  Based on 24 hour weighted average (adjusted for evening and night-time events)  Does not consider other impacts:  Vibration from takeoff run-up or landing reverse thrust  Sleep disturbance from nighttime flights  Individual events can be louder than 65 db KEY ISSUES AND CONSIDERATIONS

 Common Outdoor Sound Levels:  Quiet suburban nighttime – 35 db  Quiet suburban daytime – 55 db  Commercial area – 65 db  Diesel truck at 50 ft – 82 db  Common Indoor Sound Levels:  Library – 35 db  Normal speech at 3 ft – 65 db  Vacuum cleaner at 10 ft – 70 db  Shouting at 3 ft – 80 db HOW LOUD IS 65 DB?

 Noise remains a primary constraint on aviation capacity  Airports and residential uses are often too close to each other  Lack of coordinated planning  Misunderstood assumptions about noise and land use compatibility  Airports and communities generally have different objectives, but both want to grow  Planning with 65 DNL has helped, but may not work for all airport/community situations UNDERSTANDING NOISE AND AVIATION

 Single Family vs. Multifamily  Outdoor living – back yards, decks, etc.  Ownership vs. renters  Sound attenuation more challenging in single family due to lifestyle considerations RESIDENTIAL CONSIDERATIONS

RECENT TRENDS

 65 dnl restriction for residential uses in surrounding communities  Significant noise mitigation requirements from runway expansions CASE STUDY - DFW

 Fairfax County, VA  Dulles Airport Noise Impact Area  60 DNL for Residential Uses “Not Recommended”  Loudon County, VA  For areas outside but within one mile of the 60 DNL contour, full disclosure statement to all prospective buyers required.  For areas between the DNL noise contours, acoustical treatment to ensure that interior noise levels within living spaces do not exceed a sound level of 45 db(A), and an avigation easement.  Residential construction prohibited in 65 DNL or greater CASE STUDY - DULLES

 Residential land uses prohibited within 60 DNL contour  Used by airport and surrounding jurisdictions and as basis for City/County IGA  County “discourages” residential development within 55 DNL  Soundproofing required for any development within 55 DNL  Aggressive monitoring program with penalties (Denver $40M to date) CASE STUDY - DIA

 Significant complaints both within and outside of 60 DNL CASE STUDY - DIA

 No new residential development permitted where noise exceeds 65 DNL  Larger airport noise zone (ANZ) that requires interior noise attenuation to 45 db DNL CASE STUDY - BWI

 California Airport Land Use Planning Handbook uses 60 db CNEL as acceptable compatibility threshold  California Code of Regulations Noise Standards establishes 65 db CNEL as “acceptable threshold” for residential uses only with interior noise attenuation to 45 db  Without attenuation, 60 db is the threshold CASE STUDY – STATE OF CALIFORNIA

OBSERVATIONS AND RECOMMENDATIONS

Recent study by National Transportation Research Board On Noise Programs outside of 65 DNL  Study surveyed 35 major airports in the US. Key findings include:  83% reported that noise issues outside of the 65 DNL are “important” to “critical”  More than 75% of their noise complaints come from outside the 65 DNL  57% have instituted noise measures outside of 65 DNL, including zoning, sound attenuation, and disclosure IS THE 65 DNL THRESHOLD ENOUGH?

WHAT THE EXPERTS HAVE TO SAY “Adopting the Part 150 guidelines is understandable: they are available to be copied, easily referenced, and widely used. They are, however, inadequate to protect either the public from the adverse effects of aircraft noise or the airport from community displeasure and activism that can limit airport operations and growth. “ Transportation Research Board, 2010

 “Many communities find that using the 65 day/night noise level (65 DNL) contour is not adequate to resolve noise impacts or complaints. This is either because of the contrast where ambient noise levels are low, and/or because the DNL calculation, which uses average noise level, does not address the degree of annoyance and disruption caused by single noise events”. Transportation Research Board, 2010 FINDINGS

 Current Airport Overlay District is appropriate, particularly for conventional residential uses  Consider some flexibility for residential uses that are part of mixed-use projects in key targeted areas:  TOD nodes  More prescriptive standards for noise attenuation (e.g., specified noise attenuation levels for interior spaces) RECOMMENDATIONS