Chapter 03. Airport Noise Control Program

“Annual day-night (average) sound level (L_dn)” means for locations in the neighborhood of an airport, the day-night (average) sound level, in decibels, resulting from the effective annual average daily traffic and the utilization of runways and flight paths that affect the noise exposure at the location in question.

“Average sound (noise) level (L_eq)” means the constant sound level, in decibels, which, in a given situation and time period, would convey the same sound energy as does the actual time-varying sound during the same period. A-weighting is understood. Unless otherwise qualified, the average is reckoned over a 24-hour day, from midnight to midnight. The mathematical formulation of average sound level is as follows: If LA_(t) represents the value of instantaneous A-weighted sound pressure level fluctuating with time, (See Formula Table below) where t₁ and t₂ are, respectively, the times marking the beginning and end of the observation period over which the average is reckoned.

“Contours of equal noise exposure” means the locus of points on the ground with a given noise exposure.

“Data range” means for a set of 24-hour measurements of L_dn, the difference between the highest value and the lowest value of L_dn in decibels.

“Day-night (average) sound level (L_dn)” means the average sound level, in decibels, reckoned over a 24-hour day with a 10 decibel weighting applied to the noise occurring during the nighttime period; that is, noise levels occurring at night are treated as though they were 10 dB higher than they actually are. The mathematical formulation of day-night sound level is as follows:

“Daytime (average sound level (L_d)” means the average sound level, in decibels, for the 15 hour time period between 0700 and 2200 (7a.m. to 10p.m.). The mathematical formulation for daytime sound level is as follows:

“Decibel (dB)” means a division of the logarithmic scale customarily used to express the ratio of two like quantities proportional to power or energy.

“Decibel scale” means a logarithmic scale used to express the ratio of two like quantities proportional to power or energy. The ratio is expressed on the decibel scale by multiplying its common logarithm by ten.

“Hourly (average) sound level, (L_h)” means the average sound level, in decibels, for a 1-hour period, usually reckoned between integral hours. There would be 24 such values per day. The mathematical formulation of hourly sound level is, for example:

“Level (L)” means the ratio, expressed on the decibel scale, of two like quantities, the second of which is a standard reference quantity.

“Nighttime (average) sound level (L_p)” means the average sound level, in decibels for the 9 hour period from 2200 to 0700 the next morning (10 p.m. to 7 a.m.). The mathematical formulation for nighttime sound level is as follows:

“Sound level (noise level) (L_A)” means the quantity in decibels measured by an instrument satisfying the requirements of American National Standard Specifications for Sound Level Meters, S1.4-1971, or its latest revision; that is, the frequency-weighted sound pressure level obtained with the standardized “fast” dynamic characteristic and the “A” frequency weighting of the sound level meter.

“Sound pressure (p)” expressed in micropascals, means a fluctuating pressure superimposed on the static atmospheric pressure in the presence of sound. Unless qualified, the term means root-mean-square sound pressure.

“Sound pressure level (L_p)” means the squared ratio, expressed the decibel scale, of the sound pressure under consideration to the standard reference pressure of 20 micropascals (= 20 micronewtons/square meter or 0.0002 dynes/square centimeter).

“Airport” means any airport licensed by the Administration.

“Airport operator” means the licensee, or any person who is designated by the licensee as airport operator and who is made responsible to the licensee for the supervision and operation of the airport.

“Effective annual average daily traffic ”EAADT" means the standard daily volume of air traffic typifying airport operations, which is determined as follows:

“Flight operation” means a single take-off, landing or flyby. (A “touch-and-go” counts as two operations.)

“Licensee” means the person, firm, agency, or political subdivision to whom the airport license is issued by the Executive Director.

“Start of takeoff roll” means the position on a runway where an aircraft starts to accelerate in taking off.

“Threshold” means that position on a runway, seen from the approach end, designated as the first point where a landing is permitted. The first point does not necessarily coincide with the start of paving.

“Utilization” means the percentage of the total number of a specific category of operations, on an annual basis, that uses a particular runway or flight track.

“Certified noise abatement plan” means a noise abatement plan accepted by the Executive Director for implementation by an airport operator.

“Daytime” means 0700 to 2200 hours (7 a.m. to 10 p.m.).

“Nighttime” means 2200 to 0700 hours (10 p.m. to 7 a.m.).

“Noise abatement plan” means a detailed program of changes in airport operation which has as its goal the reduction or elimination of impacted land use areas.

Contours of equal noise exposure in terms of the day-night average sound level are to be prepared using a procedure designed to develop L_dn contours based on data as described in this section. The use of a particular procedure is subject to the approval of the Executive Director.

Data Base. The following information is required to develop contours of equal noise exposure:

Noise Measurement System Requirements.

Measurement Requirements.

Assessment of the noise environment created by the operation of their airports, including current conditions and projections of future usage;

Delineation of the noise zone, if any, base year and future year contours of equal noise exposure, and the identification of any impacted land-use areas;

Development of a plan to reduce or eliminate the impacted land-use area.

An airport operator, or the intended operator of a proposed airport, shall prepare the airport data base described by Regulation .02D(2) of this chapter. The data are to be presented as maps and supplemental information in the manner required by the Executive Director, as described in §B(2)—(4) of this regulation.

Base Year Noise Contour. Contours of equal noise exposure shall be developed representing cumulative noise levels for a full 12-month period that typifies current airport operations. The base year for a proposed airport is the initial year of operation.

Future Year Noise Contours. Contours of equal noise exposure shall be developed representing projected cumulative noise levels for a full 12-month period expected 5 years beyond the year of certification for all airports, and 10 years beyond the year of certification for air carrier airports.

Airport Noise Zone. When base year or future year contours of equal noise exposure include land uses within which the cumulative noise exposure is equal to or greater than the lowest limit for cumulative noise exposure established in Regulation .03B of this chapter, a composite of the base and future years' noise contours shall be developed as an airport noise zone that provides the greatest protection to public health and welfare.

Airports shall submit data when required as part of an environmental impact study or by the Administration;

Airports shall submit data by July 1 of each 5th year pursuant to Transportation Article, §5-805(c), Annotated Code of Maryland.

An airport operator shall obtain or prepare a map at a scale specified by the Administration showing land use within the noise zone of the airport as described under §B(3) of this regulation. All land uses shall be defined in terms consistent with the land use descriptions in Regulation .03 of this chapter and pursuant to Transportation Article, §5-805, Annotated Code of Maryland. For proposed airports, the land uses are those anticipated at the time of initial airport operation.

The operator shall identify impacted land-use areas, if any, and prepare a map clearly indicating the impacted land-use areas for any of the periods investigated in compliance with Transportation Article, §5-805(a)(1), (2), and (3), Annotated Code of Maryland. The Executive Director, at the request of the operator, may assist in the identification of impacted land-use areas.

If no impacted land-use areas exist, or will exist for any of the periods investigated, the operator shall submit a proposal to the Executive Director for certification of a noise zone for the airport. The noise zone shall be the one that provides, by its extent, the greatest protection to the public health and welfare.

If impacted land-use areas exist, or will exist for any of the periods investigated, the operator shall develop and implement a noise abatement plan in accordance with the procedures of §F of this regulation.

The goal of a noise abatement plan is the reduction or elimination of impacted land-use area.

An airport operator shall develop proposals for noise abatement plans which can meet this goal through the use of available methods in accordance with the Transportation Article, §5-805(a) and (b), Annotated Code of Maryland.

Noise abatement plans shall be submitted to the Executive Director for approval and certification of the noise zone in accordance with Transportation Article, §5-805, Annotated Code of Maryland. The noise zone shall be the one that provides, by its extent, the greatest protection to the public health and welfare in accordance with Transportation Article, §5-804, Annotated Code of Maryland.

Airport operators shall implement approved plans consistent with provisions of Transportation Article, §5-806, Annotated Code of Maryland.

Except as provided in §B(3) of this regulation, a person wishing to establish or construct a new structure, or to make new uses of land or structures, or to replace existing structures, or to make substantial changes in a structure or use of land, or to make substantial repairs to a structure within the noise zone surrounding a State-owned airport, shall obtain a permit from the Executive Director before the undertaking may begin.

Application for the permits shall be in a form required by the Executive Director, and shall include:

Notwithstanding §B(1) of this regulation, the Administration may not require a person to obtain a permit to construct an addition to a residential structure in a noise zone if the:

In accordance with Transportation Article, §5-821, Annotated Code of Maryland, the Executive Director may not grant a permit if the proposed action will enlarge the size of or create an impacted land-use area or violate local land-use and zoning laws.

Variances are available only in accordance with the provisions of Transportation Article, §5-822(a) and (b), Annotated Code of Maryland.

For purposes of administration of this regulation the following terms are defined:

Unless a person has an appropriate permit issued by the Administration or a variance granted by the Board of Airport Zoning Appeals, a political subdivision may not approve a final subdivision plan or issue any permit that is prerequisite to the construction of improvements in a noise zone established pursuant to Transportation Article, §5-821, Annotated Code of Maryland.