Transcript Grandview Sub-Area Plan

AIRPORT COMPATIBILITY
AND RESIDENTIAL
LAND USES
Town of Morrisville, NC
November 2012
OVERVIEW
Background and Context
Recent Trends
Observations and Recommendations
BACKGROUND AND
CONTEXT
AIRPORT COMPATIBILIT Y DEFINED
 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)
KEY ISSUES AND CONSIDERATIONS
 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 10-20 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
HOW LOUD IS 65 DB?
 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
UNDERSTANDING NOISE AND AVIATION
 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 dif ferent objectives,
but both want to grow
 Planning with 65 DNL has helped, but may not work for all
airport/community situations
RESIDENTIAL CONSIDERATIONS
 Single Family vs. Multifamily
 Outdoor living – back yards, decks,
etc.
 Ownership vs. renters
 Sound attenuation more challenging
in single family due to lifestyle
considerations
RECENT TRENDS
CASE STUDY - DFW
 65 dnl restriction for
residential uses in
surrounding communities
 Significant noise mitigation
requirements from runway
expansions
CASE STUDY - DULLES
 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 60-65 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 - DIA
 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 - BWI
 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 – STATE OF CALIFORNIA
 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
OBSERVATIONS AND
RECOMMENDATIONS
IS THE 65 DNL THRESHOLD ENOUGH?
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
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
FINDINGS
 “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”.
Transpor tation Research Board, 2010
RECOMMENDATIONS
 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)