Chapter 2

Background on the Environmental Criteria and Standards

in 24 CFR Part 51

[Part 51](http://www.gpoaccess.gov/cfr/index.html) contains one subpart
(Subpart A) that establishes some general

definitions of responsibility and three subparts (B-D) that establish

specific environmental standards. Because Subpart A is a purely

administrative section, of interest primarily to HUD staff, it is not

discussed in this Chapter. It is, however, included in both Chapters 3
and

4\.

NOISE ABATEMENT AND CONTROL

SUBPART B

Summary

The purpose of the noise regulation is to encourage land use patterns

for housing and other noise sensitive urban needs that will provide a

suitable separation between them and major noise sources. It provides

minimum national standards applicable to HUD programs to protect
citizens

against excessive noise in their communities and places of residence. It

also provides policy on the use of structural and other noise
attenuation

measures.

Historical Background

The Department of Housing and Urban Development\'s concern with the

problem of noise is a longstanding one. As early as 1961 The Federal

Housing Administration\'s appraisal guidance identified noise as an
issue to

be considered in property appraisals as part of our efforts to meet the

requirements of the Housing Act of 1949 which set forth the national
goal

of \"a decent home and a suitable living environment for every American

Family.\"

In the mid 1960\'s, attention was focused on aircraft noise with the

issuance of a report by the Executive Office of the President on

Alleviation of Jet Aircraft Noise Near Airports. The report was prepared

by a jet Aircraft Noise Panel composed of Federal, State and local

officials and representatives of the airport operators, airlines, and

aircraft manufacturing industry. Subsequently, a Federal Interagency

Aircraft Noise Abatement Program (IANAP) was established and emphasis
was

placed on the three major aspects of the problem: the noise source (the

aircraft), the noise path (how aircraft are flown), and the receiver
(those

living around airports). HUD was charged with chairing two interagency

panels on the receiver portion of the problem, namely compatible land
use

planning and development around airports and methods of providing

attenuation features in residential structures. Several studies were

undertaken in support of the IANAP effort. About the same time, the

Housing and Urban Development Act of 1965 was enacted. Under this Act,
the

Secretary was tasked to \"determine feasible methods of reducing the

economic loss and hardships suffered by homeowners as a result of the

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depreciation in the value of their properties following the construction
of

airports in the vicinity of their homes, including a study of feasible

methods of insulating such homes from the noise of aircraft.\"

The Department\'s first comprehensive noise standards were issued in

1971 in HUD Circular 1390.2: Noise Abatement and Control. This Circular

contained standards for exterior noise levels along with policies for

approving HUD supported or assisted housing projects in high noise
areas.

In general, the Circular established three zones: an acceptable zone
where

all projects could be approved, a normally unacceptable zone where

mitigation measures would be required and where each project would have
to

be individually evaluated for approval or denial, and an unacceptable
zone

in which projects would not, as a rule, be approved.

During the 1970\'s significant improvements were made in the technology

of noise measurement and description. In 1979, HUD issued the current

noise regulation which reflects these changes and replaces the old
Circular

1390.2. The Department kept the same basic standards but adopted new

descriptor systems which were considerably advanced over those in use

before.

While there continue to be improvements in noise measurement systems

and computer noise modeling techniques, these are primarily refinements
to

the existing systems and techniques rather than major changes. Therefore

the Department does not expect to make any significant revisions to its

noise regulation anytime in the near future.

HUD\'s concern and involvement with the noise issue has been part of a

larger Federal involvement with the noise problem. For example, the

Department of Defense has had an aggressive program to promote
compatible

development around its installations since the early 1970\'s. (The Air

Installation Compatible Use Zone program, as it is called, is a major

source of noise data for HUD.) The Federal Aviation Administration has
been

working towards a quieter aviation environment for years as well. The

focus of much of their earlier efforts was source reduction through
their

Federal Aviation Regulation 36 standards for engine noise. More recently

the FAA has been looking at land use planning as another approach to

reducing conflicts between aircraft noise and development through 46 CFR

Part 150 on airport noise compatibility planning. The Federal Highway

Administration has been working towards reducing highway noise conflicts

through standards for new highway construction and guidance to States
and

localities. And finally, the Environmental Protection Agency had been a

major force in source reduction and standards setting, particularly
during

the time Part 51B was under development.

Background on the Standards

Noise has two different types of effects on people: the direct

physical effects such as hearing loss and the less direct effects of

interference with activities such as sleep and conversation. The
standards

contained in the noise regulation are based on levels which cause

interference effects, not the levels which can cause hearing loss.

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The Noise Control Act of 1972 required the Environmental Protection

Agency to set criteria for noise levels adequate to protect health and

welfare with an adequate margin of safety but without regard to cost or

feasibility. To develop these criteria, the EPA drew upon a large body
of

survey data describing the degree of activity interference and resulting

annoyance for a variety of noise levels. These surveys are summarized in

the 1974 EPA report Information an Levels of Environmental Noise
Requisite

to Protect Public Health and Welfare With An Adequate Margin of Safety.

Most of the surveys indicated that there were two breakpoints in

reported interference and annoyance. Below 55 Ldn there was very little

interference (for example, speech intelligibility was over 99%) and very

little resulting annoyance. (Ldn stands for the Day-Night Average Sound

Level and is the noise description system currently in use. It
represents

the average of all sound levels that occur during a 24 hour period, with
a

significant penalty added to sound levels between 10 pm and 7 am. See

Figure 1 for an example of aircraft noise contours developed using the
Ldn

system.) Over 65 Ldn, interference and annoyance both increase rapidly.

The EPA set 55 Ldn as the basic goal. But other Federal agencies, in

consideration of their own program requirements and goals as well as the

difficulty of actually achieving a goal of 55 Ldn, have settled on the
65

Ldn level as their standard. At 65 Ldn activity interference is kept to
a

minimum, and annoyance levels are still low. It is also a level that we

can realistically expect to achieve. Following the Federal lead, most

local jurisdictions that have adopted noise standards have adopted 65
Ldn

as the breakpoint for acceptability.

The common thinking of the various Federal agencies involved in the

noise problem is reflected in a publication issued by the Federal

Interagency Committee on Urban Noise: Guidelines for Considering Noise

in Land Use Planning and Control. This booklet contains fairly specific

land use recommendations and advice on various techniques that might be

used to foster more compatible development. The booklet was the joint

effort of the Environmental Protection Agency, the Department of

Transportation, The Department of Defense, The Veterans Administration,

and the Department of Housing and Urban Development.

Implementing Materials

The basic document needed to implement the noise regulation is the

Noise Assessment Guidelines. These Guidelines contain desk top methods
for

calculating noise levels from aircraft, highways and railroads. The

Guidelines also contain procedures for estimating the noise reduction
from

barriers and berms. The Guidelines are available from the Department of

Housing and Urban Development. Contact the regional HUD office.

Also available is the Noise Guidebook. The Noise Guidebook is more of

a background report that contains information on the basics of noise,
noise

legislation, noise attenuation and noise measurements. It also contains
a

series of tests so it can be used as a self-teaching device. It is

available from the HUD User service. The address for the HUD User is:
HUD

User; P.O. Box 280; Germantown, MD 20874.

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Ldn Noise Contours

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