14 C.F.R. Subpart C—Evaluations and Determinations of Effects of Noise Compatibility Programs
Title 14 - Aeronautics and Space
(a) Upon receipt of a noise compatibility program submitted under §150.23, the Regional Airports Division Manager acknowledges to the airport operator receipt of the program and conducts a preliminary review of the submission. (b) If, based on the preliminary review, the Regional Airports Division Manager finds that the submission does not conform to the requirements of this part, he disapproves and returns the unacceptable program to the airport operator for reconsideration and development of a program in accordance with this part. (c) If, based on the preliminary review, the Regional Airports Division Manager finds that the program conforms to the requirements of this part, the Regional Airports Division Manager publishes in the (1) The airport covered by the program, and the date of receipt. (2) The availability of the program for examination in the offices of the Regional Airports Division Manager and the airport operator. (3) That comments on the program are invited and, will be considered by the FAA. (d) The date of signature of the published notice of receipt starts the 180-day approval period for the program. [Doc. No. 18691, 49 FR 49269, Dec. 18, 1984, as amended by Amdt. 150–2, 54 FR 39295, Sept. 25, 1989] (a) The FAA conducts an evaluation of each noise compatibility program and, based on that evaluation, either approves or disapproves the program. The evaluation includes consideration of proposed measures to determine whether they— (1) May create an undue burden on interstate or foreign commerce (including unjust discrimination); (2) Are reasonably consistent with obtaining the goal of reducing existing noncompatible land uses and preventing the introduction of additional noncompatible land uses; and (3) Include the use of new or modified flight procedures to control the operation of aircraft for purposes of noise control, or affect flight procedures in any way. (b) The evaluation may also include an evaluation of those proposed measures to determine whether they may adversely affect the exercise of the authority and responsibilities of the Administrator under the Federal Aviation Act of 1958, as amended. (c) To the extent considered necessary, the FAA may— (1) Confer with the airport operator and other persons known to have information and views material to the evaluation; (2) Explore the objectives of the program and the measures, and any alternative measures, for achieving the objectives. (3) Examine the program for developing a range of alternatives that would eliminate the reasons, if any, for disapproving the program. (4) Convene an informal meeting with the airport operator and other persons involved in developing or implementing the program for the purposes of gathering all facts relevant to the determination of approval or disapproval of the program and of discussing any needs to accommodate or modify the program as submitted. (d) If requested by the FAA, the airport operator shall furnish all information needed to complete FAA's review under (c). (e) An airport operator may, at any time before approval or disapproval of a program, withdraw or revise the program. If the airport operator withdraws or revises the program or indicates to the Regional Airports Division Manager, in writing, the intention to revise the program, the Regional Airports Division Manager terminates the evaluation and notifies the airport operator of that action. That termination cancels the 180-day review period. The FAA does not evaluate a second program for any airport until any previously submitted program has been withdrawn or a determination on it is issued. A new evaluation is commenced upon receipt of a revised program, and a new 180-day approval period is begun, unless the Regional Airports Division Manager finds that the modification made, in light of the overall revised program, can be integrated into the unmodified portions of the revised program without exceeding the original 180-day approval period or causing undue expense to the government. [Doc. No. 18691, 49 FR 49269, Dec. 18, 1984, as amended by Amdt. 150–2, 54 FR 39295, Sept. 25, 1989] (a) The FAA issues a determination approving or disapproving each airport noise compatibility program (and revised program). Portions of a program may be individually approved or disapproved. No conditional approvals will be issued. A determination on a program acceptable under this part is issued within 180 days after the program is received under §150.23 of this part or it may be considered approved, except that this time period may be exceeded for any portion of a program relating to the use of flight procedures for noise control purposes. A determination on portions of a program covered by the exceptions to the 180-day review period for approval will be issued within a reasonable time after receipt of the program. Determinations relating to the use of any flight procedure for noise control purposes may be issued either in connection with the determination on other portions of the program or separately. Except as provided by this paragraph, no approval of any noise compatibility program, or any portion of a program, may be implied in the absence of the FAA's express approval. (b) The Administrator approves programs under this part, if— (1) It is found that the program measures to be implemented would not create an undue burden on interstate or foreign commerce (including any unjust discrimination) and are reasonably consistent with achieving the goals of reducing existing noncompatible land uses around the airport and of preventing the introduction of additional noncompatible land uses; (2) The program provides for revision if made necessary by the revision of the noise map; and (3) Those aspects of programs relating to the use of flight procedures for noise control can be implemented within the period covered by the program and without— (i) Reducing the level of aviation safety provided; (ii) Derogating the requisite level of protection for aircraft, their occupants and persons and property on the ground; (iii) Adversely affecting the efficient use and management of the Navigable Airspace and Air Traffic Control Systems; or (iv) Adversely affecting any other powers and responsibilities of the Administrator prescribed by law or any other program, standard, or requirement established in accordance with law. (c) When a determination is issued, the Regional Airports Division Manager notifies the airport operator and publishes a notice of approval or disapproval in the (d) Approvals issued under this part for a program or portion thereof become effective as specified therein and may be withdrawn when one of the following occurs: (1) The program or portion thereof is required to be revised under this part or under its own terms, and is not so revised; (2) If a revision has been submitted for approval, a determination is issued on the revised program or portion thereof, that is inconsistent with the prior approval. (3) A term or condition of the program, or portion thereof, or its approval is violated by the responsible government body. (4) A flight procedure or other FAA action upon which the approved program or portion thereof is dependent is subsequently disapproved, significantly altered, or rescinded by the FAA. (5) The airport operator requests rescission of the approval. (6) Impacts on flight procedures, air traffic management, or air commerce occur which could not be foreseen at the time of approval. A determination may be sooner rescinded or modified for cause with at least 30 days written notice to the airport operator of the FAA's intention to rescind or modify the determination for the reasons stated in the notice. The airport operator may, during the 30-day period, submit to the Regional Airports Division Manager for consideration any reasons and circumstances why the determination should not be rescinded or modified on the basis stated in the notice of intent. Thereafter, the FAA either rescinds or modifies the determination consistent with the notice or withdraws the notice of intent and terminates the action. (e) Determinations may contain conditions which must be satisfied prior to implementation of any portion of the program relating to flight procedures affecting airport or aircraft operations. (f) Noise exposure maps for current and forecast year map conditions that are submitted and approved with noise compatibility programs are considered to be the new FAA accepted noise exposure maps for purposes of part 150. [Doc. No. 18691, 49 FR 49269, Dec. 18, 1984, as amended by Amdt. 150–2, 54 FR 39295, Sept. 25, 1989; Amdt. 150–4, 69 FR 57626, Sept. 24, 2004] Part A—General Sec. A150.1 Purpose. Sec. A150.3 Noise descriptors. Sec. A150.5 Noise measurement procedures and equipment. Part B—Noise Exposure Map Development Sec. A150.101 Noise contours and land usages. Sec. A150.103 Use of computer prediction model. Sec. A150.105 Identification of public agencies and planning agencies. Part C—Mathematical Descriptions Sec. A150.201 General. Sec. A150.203 Symbols. Sec. A150.205 Mathematical computations. Part A—General Sec. A150.1 Purpose. (a) This appendix establishes a uniform methodology for the development and preparation of airport noise exposure maps. That methodology includes a single system of measuring noise at airports for which there is a highly reliable relationship between projected noise exposure and surveyed reactions of people to noise along with a separate single system for determining the exposure of individuals to noise. It also identifies land uses which, for the purpose of this part are considered to be compatible with various exposures of individuals to noise around airports. (b) This appendix provides for the use of the FAA's Integrated Noise Model (INM) or an FAA approved equivalent, for developing standardized noise exposure maps and predicting noise impacts. Noise monitoring may be utilized by airport operators for data acquisition and data refinement, but is not required by this part for the development of noise exposure maps or airport noise compatibility programs. Whenever noise monitoring is used, under this part, it should be accomplished in accordance with Sec. A150.5 of this appendix. Sec. A150.3 Noise descriptors. (a) Airport Noise Measurement. The A-Weighted Sound Level, measured, filtered and recorded in accordance with Sec. A150.5 of this appendix, must be employed as the unit for the measurement of single event noise at airports and in the areas surrounding the airports. (b) Airport Noise Exposure. The yearly day-night average sound level (YDNL) must be employed for the analysis and characterization of multiple aircraft noise events and for determining the cumulative exposure of individuals to noise around airports. Sec. A150.5 Noise measurement procedures and equipment. (a) Sound levels must be measured or analyzed with equipment having the “A” frequency weighting, filter characteristics, and the “slow response” characteristics as defined in International Electrotechnical Commission (IEC) Publication No. 179, entitled “Precision Sound Level Meters” as incorporated by reference in part 150 under §150.11. For purposes of this part, the tolerances allowed for general purpose, type 2 sound level meters in IEU 179, are acceptable. (b) Noise measurements and documentation must be in accordance with accepted acoustical measurement methodology, such as those described in American National Standards Institute publication ANSI 51.13, dated 1971 as revised 1979, entitled “ANS—Methods for the Measurement of Sound Pressure Levels”; ARP No. 796, dated 1969, entitled “Measurement of Aircraft Exterior Noise in the Field”; “Handbook of Noise Measurement,” Ninth Ed. 1980, by Arnold P.G. Peterson; or “Acoustic Noise Measurement,” dated Jan., 1979, by J.R. Hassell and K. Zaveri. For purposes of this part, measurements intended for comparison to a State or local standard or with another transportation noise source (including other aircraft) must be reported in maximum A-weighted sound levels (LAM); for computation or validation of the yearly day-night average level (Ldn), measurements must be reported in sound exposure level (LAE), as defined in Sec. A150.205 of this appendix. Part B—Noise Exposure Map Development Sec. A150.101 Noise contours and land usages. (a) To determine the extent of the noise impact around an airport, airport proprietors developing noise exposure maps in accordance with this part must develop Ldn contours. Continuous contours must be developed for YDNL levels of 65, 70, and 75 (additional contours may be developed and depicted when appropriate). In those areas where YDNL values are 65 YDNL or greater, the airport operator shall identify land uses and determine land use compatibility in accordance with the standards and procedures of this appendix. (b) Table 1 of this appendix describes compatible land use information for several land uses as a function of YDNL values. The ranges of YDNL values in Table 1 reflect the statistical variability for the responses of large groups of people to noise. Any particular level might not, therefore, accurately assess an individual's perception of an actual noise environment. Compatible or noncompatible land use is determined by comparing the predicted or measured YDNL values at a site with the values given. Adjustments or modifications of the descriptions of the land-use categories may be desirable after consideration of specific local conditions. (c) Compatibility designations in Table 1 generally refer to the major use of the site. If other uses with greater sensitivity to noise are permitted by local government at a site, a determination of compatibility must be based on that use which is most adversely affected by noise. When appropriate, noise level reduction through incorporation of sound attenuation into the design and construction of a structure may be necessary to achieve compatibility. (d) For the purpose of compliance with this part, all land uses are considered to be compatible with noise levels less than Ldn 65 dB. Local needs or values may dictate further delineation based on local requirements or determinations. (e) Except as provided in (f) below, the noise exposure maps must also contain and indentify: (1) Runway locations. (2) Flight tracks. (3) Noise contours of Ldn 65, 70, and 75 dB resulting from aircraft operations. (4) Outline of the airport boundaries. (5) Noncompatible land uses within the noise contours, including those within the Ldn 65 dB contours. (No land use has to be identified as noncompatible if the self-generated noise from that use and/or the ambient noise from other nonaircraft and nonairport uses is equal to or greater than the noise from aircraft and airport sources.) (6) Location of noise sensitive public buildings (such as schools, hospitals, and health care facilities), and properties on or eligible for inclusion in the National Register of Historic Places. (7) Locations of any aircraft noise monitoring sites utilized for data acquisition and refinement procedures. (8) Estimates of the number of people residing within the Ldn 65, 70, and 75 dB contours. (9) Depiction of the required noise contours over a land use map of a sufficient scale and quality to discern streets and other identifiable geographic features. (f) Notwithstanding any other provision of this part, noise exposure maps prepared in connection with studies which were either Federally funded or Federally approved and which commenced before October 1, 1981, are not required to be modified to contain the following items: (1) Flight tracks depicted on the map. (2) Use of ambient noise to determine land use compatibility. (3) The Ldn 70 dB noise contour and data related to Ldn 70 dB contour. When determinations on land use compatibility using Table 1 differ between Ldn 65–70 dB and the Ldn 70–75 dB, determinations should either use the more conservative Ldn 70–75 dB column or reflect determinations based on local needs and values. (4) Estimates of the number of people residing within the Ldn 65, 70, and 75 dB contours. Sec. A150.103 Use of computer prediction model. (a) The airport operator shall acquire the aviation operations data necessary to develop noise exposure contours using an FAA approved methodology or computer program, such as the Integrated Noise Model (INM) for airports or the Heliport Noise Model (HNM) for heliports. In considering approval of a methodology or computer program, key factors include the demonstrated capability to produce the required output and the public availability of the program or methodology to provide interested parties the opportunity to substantiate the results. (b) Except as provided in paragraph (c) of this section, the following information must be obtained for input to the calculation of noise exposure contours: (1) A map of the airport and its environs at an adequately detailed scale (not less than 1 inch to 2,000 feet) indicating runway length, alignments, landing thresholds, takeoff start-of-roll points, airport boundary, and flight tracks out to at least 30,000 feet from the end of each runway. (2) Airport activity levels and operational data which will indicate, on an annual average-daily-basis, the number of aircraft, by type of aircraft, which utilize each flight track, in both the standard daytime (0700–2200 hours local) and nighttime (2200–0700 hours local) periods for both landings and takeoffs. (3) For landings—glide slopes, glide slope intercept altitudes, and other pertinent information needed to establish approach profiles along with the engine power levels needed to fly that approach profile. (4) For takeoffs—the flight profile which is the relationship of altitude to distance from start-of-roll along with the engine power levels needed to fly that takeoff profile; these data must reflect the use of noise abatement departure procedures and, if applicable, the takeoff weight of the aircraft or some proxy for weight such as stage length. (5) Existing topographical or airspace restrictions which preclude the utilization of alternative flight tracks. (6) The government furnished data depicting aircraft noise characteristics (if not already a part of the computer program's stored data bank). (7) Airport elevation and average temperature. (c) For heliports, the map scale required by paragraph (b)(1) of this section shall not be less than 1 inch to 2,000 feet and shall indicate heliport boundaries, takeoff and landing pads, and typical flight tracks out to at least 4,000 feet horizontally from the landing pad. Where these flight tracks cannot be determined, obstructions or other limitations on flight tracks in and out of the heliport shall be identified within the map areas out to at least 4,000 feet horizontally from the landing pad. For static operation (hover), the helicopter type, the number of daily operations based on an annual average, and the duration in minutes of the hover operation shall be identified. The other information required in paragraph (b) shall be furnished in a form suitable for input to the HNM or other FAA approved methodology or computer program. Sec. A150.105 Identification of public agencies and planning agencies. (a) The airport proprietor shall identify each public agency and planning agency whose jurisdiction or responsibility is either wholly or partially within the Ldn 65 dB boundary. (b) For those agencies identified in (a) that have land use planning and control authority, the supporting documentation shall identify their geographic areas of jurisdiction. Part C—Mathematical Descriptions Sec. A150.201 General. The following mathematical descriptions provide the most precise definition of the yearly day-night average sound level (Ldn), the data necessary for its calculation, and the methods for computing it. Sec. A150.203 Symbols. The following symbols are used in the computation of Ldn; Sec. A150.205 Mathematical computations. (a) Average sound level must be computed in accordance with the following formula: where T is the length of the time period, in seconds, during which the average is taken; LA(t) is the instantaneous time varying A-weighted sound level during the time period T. Note: When a noise environment is caused by a number of identifiable noise events, such as aircraft flyovers, average sound level may be conveniently calculated from the sound exposure levels of the individual events occurring within a time period T: where LAEi is the sound exposure level of the i-th event, in a series of n events in time period T, in seconds. Note: When T is one hour, LT is referred to as one-hour average sound level. (b) Day-night average sound level (individual day) must be computed in accordance with the following formula: Time is in seconds, so the limits shown in hours and minutes are actually interpreted in seconds. It is often convenient to compute day-night average sound level from the one-hour average sound levels obtained during successive hours. (c) Yearly day-night average sound level must be computed in accordance with the following formula: where Ldni is the day-night average sound level for the i-th day out of one year. (d) Sound exposure level must be computed in accordance with the following formula: where to is one second and LA(t) is the time-varying A-weighted sound level in the time interval t1 to t2. The time interval should be sufficiently large that it encompasses all the significant sound of a designated event. The requisite integral may be approximated with sufficient accuracy by integrating LA(t) over the time interval during which LA(t) lies within 10 decibels of its maximum value, before and after the maximum occurs. [Doc. No. 18691, 49 FR 49269, Dec. 18, 1984; 50 FR 5064, Feb. 6, 1985, as amended by Amdt. 150–1, 53 FR 8724, Mar. 16, 1988; Amdt. 150–4, 69 FR 57626, Sept. 24, 2004] Sec. B150.1 Scope and purpose. Sec. B150.3 Requirement for noise map. Sec. B150.5 Program standards. Sec. B150.7 Analysis of program alternatives. Sec. B150.9 Equivalent programs. Sec. B150.1 Scope and purpose. (a) This appendix prescribes the content and the methods for developing noise compatibility programs authorized under this part. Each program must set forth the measures which the airport operator (or other person or agency responsible) has taken, or proposes to take, for the reduction of existing noncompatible land uses and the prevention of the introduction of additional noncompatible land uses within the area covered by the noise exposure map submitted by the operator. (b) The purpose of a noise compatibility program is: (1) To promote a planning process through which the airport operator can examine and analyze the noise impact created by the operation of an airport, as well as the costs and benefits associated with various alternative noise reduction techniques, and the responsible impacted land use control jurisdictions can examine existing and forecast areas of noncompatibility and consider actions to reduce noncompatible uses. (2) To bring together through public participation, agency coordination, and overall cooperation, all interested parties with their respective authorities and obligations, thereby facilitating the creation of an agreed upon noise abatement plan especially suited to the individual airport location while at the same time not unduly affecting the national air transportation system. (3) To develop comprehensive and implementable noise reduction techniques and land use controls which, to the maximum extent feasible, will confine severe aircraft YDNL values of Ldn 75 dB or greater to areas included within the airport boundary and will establish and maintain compatible land uses in the areas affected by noise between the Ldn 65 and 75 dB contours. Sec. B150.3 Requirement for noise map. (a) It is required that a current and complete noise exposure map and its supporting documentation as found in compliance with the applicable requirements by the FAA, per §150.21(c) be included in each noise compatibility program: (1) To identify existing and future noncompatible land uses, based on airport operation and off-airport land uses, which have generated the need to develop a program. (2) To identify changes in noncompatible uses to be derived from proposed program measures. (b) If the proposed noise compatibility program would yield maps differing from those previously submitted to FAA, the program shall be accompanied by appropriately revised maps. Such revisions must be prepared in accordance with the requirements of Sec. A150.101(e) of appendix A and will be accepted by FAA in accordance with §150.35(f). Sec. B150.5 Program standards. Based upon the airport noise exposure and noncompatible land uses identified in the map, the airport operator shall evaluate the several alternative noise control actions and develop a noise compatibility program which— (a) Reduces existing noncompatible uses and prevents or reduces the probability of the establishment of additional noncompatible uses; (b) Does not impose undue burden on interstate and foreign commerce; (c) Provides for revision in accordance with §150.23 of this part. (d) Is not unjustly discriminatory. (e) Does not derogate safety or adversely affect the safe and efficient use of airspace. (f) To the extent practicable, meets both local needs and needs of the national air transportation system, considering tradeoffs between economic benefits derived from the airport and the noise impact. (g) Can be implemented in a manner consistent with all of the powers and duties of the Administrator of FAA. Sec. B150.7 Analysis of program alternatives. (a) Noise control alternatives must be considered and presented according to the following categories: (1) Noise abatement alternatives for which the airport operator has adequate implementation authority. (2) Noise abatement alternatives for which the requisite implementation authority is vested in a local agency or political subdivision governing body, or a state agency or political subdivision governing body. (3) Noise abatement options for which requisite authority is vested in the FAA or other Federal agency. (b) At a minimum, the operator shall analyze and report on the following alternatives, subject to the constraints that the strategies are appropriate to the specific airport (for example, an evaluation of night curfews is not appropriate if there are no night flights and none are forecast): (1) Acquisition of land and interests therein, including, but not limited to air rights, easements, and development rights, to ensure the use of property for purposes which are compatible with airport operations. (2) The construction of barriers and acoustical shielding, including the soundproofing of public buildings. (3) The implementation of a preferential runway system. (4) The use of flight procedures (including the modifications of flight tracks) to control the operation of aircraft to reduce exposure of individuals (or specific noise sensitive areas) to noise in the area around the airport. (5) The implementation of any restriction on the use of airport by any type or class of aircraft based on the noise characteristics of those aircraft. Such restrictions may include, but are not limited to— (i) Denial of use of the airport to aircraft types or classes which do not meet Federal noise standards; (ii) Capacity limitations based on the relative noisiness of different types of aircraft; (iii) Requirement that aircraft using the airport must use noise abatement takeoff or approach procedures previously approved as safe by the FAA; (iv) Landing fees based on FAA certificated or estimated noise emission levels or on time of arrival; and (v) Partial or complete curfews. (6) Other actions or combinations of actions which would have a beneficial noise control or abatement impact on the public. (7) Other actions recommended for analysis by the FAA for the specific airport. (c) For those alternatives selected for implementation, the program must identify the agency or agencies responsible for such implementation, whether those agencies have agreed to the implementation, and the approximate schedule agreed upon. Sec. B150.9 Equivalent programs. (a) Notwithstanding any other provision of this part, noise compatibility programs prepared in connection with studies which were either Federally funded or Federally approved and commenced before October 1, 1981, are not required to be modified to contain the following items: (1) Flight tracks. (2) A noise contour of Ldn 70 dB resulting from aircraft operations and data related to the Ldn 70 dB contour. When determinations on land use compatibility using Table 1 of appendix A differ between Ldn 65–70 dB and Ldn 70–75 dB, the determinations should either use the more conservative Ldn 70–75 dB column or reflect determinations based on local needs and values. (3) The categorization of alternatives pursuant to Sec. B150.7(a), although the persons responsible for implementation of each measure in the program must still be identified in accordance with §150.23(e)(8). (4) Use of ambient noise to determine land use compatibility. (b) Previously prepared noise compatibility program documentation may be supplemented to include these and other program requirements which have not been excepted.
Title 14: Aeronautics and Space
PART 150—AIRPORT NOISE COMPATIBILITY PLANNING
Subpart C—Evaluations and Determinations of Effects of Noise Compatibility Programs
§ 150.31 Preliminary review: Acknowledgments.
§ 150.33 Evaluation of programs.
§ 150.35 Determinations; publications; effectivity.
Appendix A to Part 150—Noise Exposure Maps
TABLE 1_Land Use Compatibility* With Yearly Day-Night Average Sound Levels---------------------------------------------------------------------------------------------------------------- Yearly day-night average sound level (Ldn) in decibels Land use --------------------------------------------------------------------------------- Below 65 65-70 70-75 75-80 80-85 Over 85---------------------------------------------------------------------------------------------------------------- ResidentialResidential, other than mobile Y N(1) N(1) N N N homes and transient lodgings.Mobile home parks............. Y N N N N NTransient lodgings............ Y N(1) N(1) N(1) N N Public UseSchools....................... Y N(1) N(1) N N NHospitals and nursing homes... Y 25 30 N N NChurches, auditoriums, and Y 25 30 N N N concert halls.Governmental services......... Y Y 25 30 N NTransportation................ Y Y Y(2) Y(3) Y(4) Y(4)Parking....................... Y Y Y(2) Y(3) Y(4) N Commercial UseOffices, business and Y Y 25 30 N N professional.Wholesale and retail_building Y Y Y(2) Y(3) Y(4) N materials, hardware and farm equipment.Retail trade_general.......... Y Y 25 30 N NUtilities..................... Y Y Y(2) Y(3) Y(4) NCommunication................. Y Y 25 30 N N Manufacturing and ProductionManufacturing, general........ Y Y Y(2) Y(3) Y(4) NPhotographic and optical...... Y Y 25 30 N NAgriculture (except livestock) Y Y(6) Y(7) Y(8) Y(8) Y(8) and forestry.Livestock farming and breeding Y Y(6) Y(7) N N NMining and fishing, resource Y Y Y Y Y Y production and extraction. RecreationalOutdoor sports arenas and Y Y(5) Y(5) N N N spectator sports.Outdoor music shells, Y N N N N N amphitheaters.Nature exhibits and zoos...... Y Y N N N NAmusements, parks, resorts and Y Y Y N N N camps.Golf courses, riding stables Y Y 25 30 N N and water recreation.----------------------------------------------------------------------------------------------------------------Numbers in parentheses refer to notes.*The designations contained in this table do not constitute a Federal determination that any use of land covered by the program is acceptable or unacceptable under Federal, State, or local law. The responsibility for determining the acceptable and permissible land uses and the relationship between specific properties and specific noise contours rests with the local authorities. FAA determinations under part 150 are not intended to substitute federally determined land uses for those determined to be appropriate by local authorities in response to locally determined needs and values in achieving noise compatible land uses.Key to Table 1SLUCM=Standard Land Use Coding Manual.Y (Yes)=Land Use and related structures compatible without restrictions.N (No)=Land Use and related structures are not compatible and should be prohibited.NLR=Noise Level Reduction (outdoor to indoor) to be achieved through incorporation of noise attenuation into the design and construction of the structure.25, 30, or 35=Land use and related structures generally compatible; measures to achieve NLR of 25, 30, or 35 dB must be incorporated into design and construction of structure.Notes for Table 1(1) Where the community determines that residential or school uses must be allowed, measures to achieve outdoor to indoor Noise Level Reduction (NLR) of at least 25 dB and 30 dB should be incorporated into building codes and be considered in individual approvals. Normal residential construction can be expected to provide a NLR of 20 dB, thus, the reduction requirements are often stated as 5, 10 or 15 dB over standard construction and normally assume mechanical ventilation and closed windows year round. However, the use of NLR criteria will not eliminate outdoor noise problems.(2) Measures to achieve NLR 25 dB must be incorporated into the design and construction of portions of these buildings where the public is received, office areas, noise sensitive areas or where the normal noise level is low.(3) Measures to achieve NLR of 30 dB must be incorporated into the design and construction of portions of these buildings where the public is received, office areas, noise sensitive areas or where the normal noise level is low.(4) Measures to achieve NLR 35 dB must be incorporated into the design and construction of portions of these buildings where the public is received, office areas, noise sensitive areas or where the normal level is low.(5) Land use compatible provided special sound reinforcement systems are installed.(6) Residential buildings require an NLR of 25.(7) Residential buildings require an NLR of 30.(8) Residential buildings not permitted.
------------------------------------------------------------------------ Measure (in dB) Symbol------------------------------------------------------------------------Average Sound Level, During Time T............................ LTDay-Night Average Sound Level (individual day)................ LdniYearly Day-Night Average Sound Level.......................... LdnSound Exposure Level.......................................... LAE------------------------------------------------------------------------
Appendix B to Part 150—Noise Compatibility Programs
