Code of Maryland Regulations › Title 26 - DEPARTMENT OF ENVIRONMENT › Part 1 - SUBTITLES 01-07 › Subtitle 02 - OCCUPATIONAL, INDUSTRIAL, AND RESIDENTIAL HAZARDS › Chapter 26.02.03 - Control of Noise Pollution › Section 26.02.03.01 - Definitions

Current through Register Vol. 51, No. 14, July 12, 2024
A. In this chapter,
				  the following terms have the meanings indicated.
B. Terms Defined.
(1) "ANSI" means American National Standards
				  Institute or its successor bodies.
(2) "Construction" means any site
				  preparation, assembly, erection, repair, alteration, or similar
				  activity.
(3) "Curtilage" means the
				  enclosed land surrounding a house or dwelling and includes all areas maintained
				  in lawn or horticultural plantings and may be bounded by a fence or wall, but
				  would not typically include areas more distant than 300 feet from the dwelling
				  unless those areas were horticulturally maintained and routinely used as areas
				  of personal refuge, or supported accessory structures that were routinely
				  utilized.
(4) "Daytime hours" means
				  7 a.m. to 10 p.m., local time.
(5)
				  "dBA" means abbreviation for the sound level in decibels determined by the
				  A-weighting network of a sound level meter or by calculation from octave band
				  or one-third octave band data.
(6)
				  "Decibel (dB)" means a unit of measure equal to ten times the logarithm to the
				  base ten of the ratio of the square of the sound pressure to the square of a
				  standard reference pressure. For the purpose of this subtitle, 20 micropascals
				  shall be the standard reference pressure.
(7) "Demolition" means any dismantling,
				  destruction, or removal activities.
(8) "Department" means the Department of the
				  Environment.
(9) "Emergency" means
				  any occurrence or set of circumstances involving actual or imminent physical
				  trauma or property damage which demands immediate action.
(10) "Environmental noise" means the noise
				  that exists at any location from all sources.
(11) "Environmental noise standards" means
				  the goals for environmental noise, the attainment and maintenance of which, in
				  defined areas and under specific conditions, are necessary to protect the
				  public health and general welfare.
(12) "Equivalent sound level" (also "average
				  sound level") means the level of a constant sound 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. Equivalent sound level is the level
				  of the time weighted, mean-square, A-weighted sound pressure. A numerical
				  subscript may be used to indicate the time period under consideration; i.e.,
				  Leq24 or Leq8 for 24-hour and
				  8-hour periods, respectively. No subscript indicates a 24-hour period. The
				  mathematical expression for the Leq is as follows:
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where t1 and
					 t2 are the beginning and ending times, respectively, of
					 the period over which the average is determined, and
					 LA(t) is the instantaneous A-weighted sound pressure
					 level fluctuating with time.
(13) "IEC" means International
				  Electrotechnical Commission.
(14)
				  "Nighttime hours" means 10 p.m. to 7 a.m., local time.
(15) "Noise" means the intensity, frequency,
				  duration, and character of sound, including sound and vibration of sub-audible
				  frequencies.
(16) "Noise pollution"
				  means the presence of noise of sufficient loudness, character, and duration,
				  which whether from a single source or multiple sources, is, or may be predicted
				  with reasonable certainty to be, injurious to health or which unreasonably
				  interferes with the proper enjoyment of property or with any lawful business or
				  activity.
(17) "Periodic noise"
				  means noise possessing a repetitive on-and-off characteristic with a rapid rise
				  to maximum and a short decay not exceeding 2 seconds.
(18) "Person" means any individual, group of
				  individuals, firm, partnership, voluntary association, or private, public, or
				  municipal corporation, or political subdivision of the State, or department,
				  bureau, agency, or instrument of federal, State, or local government,
				  responsible for the use of property.
(19) "Prominent discrete tone" means any
				  sound which can be distinctly heard as a single pitch or a set of single
				  pitches. For the purposes of this regulation, a prominent discrete tone shall
				  exist if the one-third octave band sound pressure level in the band with the
				  tone exceeds the arithmetic average of the sound pressure levels of the 2
				  contiguous one-third octave bands by 5 dB for center frequencies of 500 Hz and
				  above and by 8 dB for center frequencies between 160 and 400 Hz and by 15 dB
				  for center frequencies less than or equal to 125 Hz.
(20) "Sound level" means, in decibels, the
				  weighted sound pressure level measured by the use of a sound level meter. Sound
				  level and noise level are synonymous. The weighting employed shall always be
				  specified.
(21) "Sound level meter"
				  means an instrument, meeting International Electrotechnical Commission and
				  American National Standards Institute standards comprising a microphone, an
				  amplifier, an output meter, and frequency weighting network(s) that is used for
				  the measurement of sound pressure levels in a specified manner.
(22) Sound Pressure.
(a) "Sound pressure" means the minute
				  fluctuations in atmospheric pressure which accompany the passage of a sound
				  wave.
(b) Sound pressure is usually
				  measured in dynes per square centimeter (dyne/cm2),
				  or in newtons per square meter (N/m2), or in
				  micropascals.
(23)
				  "Sound pressure level" means, in decibels, 20 times the logarithm to the base
				  ten of the ratio of a sound pressure to the reference sound pressure of 20
				  micropascals (20 micronewtons per square meter). In the absence of any
				  modifier, the pressure is understood to be that of a root mean-square
				  pressure.
(24) "Source" means any
				  person or property, real or personal, contributing to noise
				  pollution.
(25) "Vibration" means
				  any oscillatory motion of solid bodies.
(26) "Zoning district" means a general land
				  use category, defined according to local subdivision, the activities and uses
				  for which are generally uniform throughout the subdivision. For the purposes of
				  this regulation, property which is not zoned "industrial", "commercial", or
				  "residential" shall be classified according to use as follows:
(a) "Industrial" means property used for
				  manufacturing and storing goods;
(b) "Commercial" means property used for
				  buying and selling goods and services;
(c) "Residential" means property used for
				  dwellings.