§ 11-5-2. Definitions.

For the purposes of this chapter, the following words and phrases shall have the meanings respectively ascribed to them by this section:

(1)

Aircraft. Any device that is used or intended to be used for flight in the air, engaged in carrying persons or property.

(2)

Acoustics. The science of sound including its generation, propagation, measurement and physiological and psychological effects.

(3)

Ambient noise. The all encompassing noise associated with a given environment, being usually a composite of sounds from many sources, near and far.

(4)

A-weighted sound level [dB(A)]. A quantity, in decibels read from a sound level meter, that is switched to the weighting network labeled "A." The A-weighted network shall be as specified under the most recent specifications of the American National Standards Institute, Inc., New York, N.Y. (ANSI).

(5)

Center frequency. For acoustic measurement, the center frequency of an octave band which is the geometric mean of the upper and lower frequency limits of the band.

(6)

Commercial use area. The area within 200 feet of all boundaries of any property producing noise or, where such property is a railroad, the area within 200 feet perpendicular to the centerline of the railroad track at the source of the noise, when the predominant use of the properties in that area is for commercial purposes.

(7)

Construction. Any or all activity necessary or incidental to the erection, demolition, assembling, altering, installing or equipping of buildings, public or private highways, roads, railroads, premises, parks, utility lines including any lines in already constructed tunnels, or other property, including land clearing, grading, excavating and filling.

(8)

Construction device. Any device designed and intended for use in construction including, but not limited to any air compressors, backhoes, concrete vibrators, cranes (derrick), cranes (mobile), dozers (track and wheel), generators, graders, loaders (track and wheel), mixers, pavement breakers, pavers, pile drivers, power hoists, rock drills, rock crushers, rollers, scrapers, and shovels.

(9)

Continuous noise. Noise whose level remains essentially constant without interruption or break.

(10)

Decibel (dB). A unit of sound magnitude equal to 20 times the logarithm to the base 10 of the ratio of the sound pressure being measured to a reference sound pressure of 20 micronewtons per square meter or 0.0002 microbars, abbreviated "dB."

(11)

Director. The director of the department transportation and environmental services of the City of Alexandria or his duly authorized representative.

(12)

Emergency signal device. Any gong, bell, siren, whistle or any horn or any similar device the use of which is permitted on authorized vehicles or which are mounted on poles, buildings, towers or other supports.

(13)

Emergency work. Work made necessary to restore property to a safe and working condition following a public calamity, or work required to protect persons or property from imminent danger.

(14)

Engineer. The noise pollution specialist designated or appointed by the director.

(15)

Exhaust system. A system which removes and transports air or gas from a device.

(16)

Hertz. A unit of measurement of frequency numerically equal to cycles per second.

(17)

Impulsive noise. A short burst of acoustical energy such as, but not limited to, that produced by weapon fire, punch press or drop hammer. A pressure time history of a single impulse includes a rapid rise to a maximum peak pressure followed by a somewhat slower decay, both occurring within one second.

(18)

Industrial use area. The area within 200 feet of all boundaries of any property producing noise or, where such property is a railroad, the area within 200 feet perpendicular to the centerline of the railroad track at the source of the noise, when the predominant use of properties in that area is for industrial purposes.

(19)

Internal combustion engine. A device for the production of energy by means of combustion under pressure.

(20)

Microbar. Unit of pressure commonly used in acoustics and equal to one dyne per square centimeter or one-tenth (0.1) Newtons per square meter.

(21)

Motorcycle. Every motor vehicle designed to travel on not more than three wheels in contact with the ground and any four wheeled vehicle weighing less than 500 pounds and equipped with an engine of less than six horsepower.

(22)

Motorized construction device. Any construction device which is a motor vehicle.

(23)

Motor vehicle. Every device in, upon or by which any person or thing is or may be transported or drawn upon a highway which is self-propelled or designed for self-propulsion, except devices used exclusively upon stationary rails or tracks.

(24)

Muffler. An apparatus generally consisting of but not limited to a series of chambers or baffles for the purpose of transmitting gases while reducing sound level.

(25)

Newton. A unit of pressure. The force required to accelerate one kilogram of mass at one meter per second squared.

(26)

Noise. A steady-state or impulsive sound or sounds occurring on either a continuous or intermittent basis or any sound which annoys or disturbs humans or which causes or tends to cause an adverse psychological or physiological effect on humans.

(27)

Noise level. See sound pressure level.

(28)

Octave band. An interval in the audible range of sound that has an upper frequency numerically exactly twice that of its lower frequency.

(29)

Owner. Owner shall have no connotations other than that customarily assigned to the term "person," but shall include bodies politic and corporate, associations, partnerships, personal representatives, trustees and committees, as well as individuals.

(30)

Person. Any individual, corporation, cooperative, partnership, firm, association, trust, estate, public or private institution, group, agency, political subdivision of this state or any legal successor, representative, agent or agency of the foregoing.

(31)

Power equipment. Motorized or engine driven equipment such as, but not limited to, powered saws or chain saws and powered hand tools including hydraulic and pneumatic hand tools. Does not include air or surface transportation vehicles, construction devices, sound signaling devices or power lawn and garden equipment.

(32)

Power lawn and garden equipment. Powered devices for care and maintenance of lawns and gardens, including but not limited to, edgers, garden tractors, hedge clippers, home tractors, lawn mowers, snow and leaf blowers, tillers, and trimmers.

(33)

Property. The smallest area owned or leased by the same person or persons.

(34)

Rail rapid transit system. A railroad used exclusively for local service in the transportation of passengers as a common carrier for hire together with the appurtenances, facilities and equipment thereof.

(35)

Railroad. All the rights-of-way of any common carrier operating a railroad, whether owned or operated under contract, agreement or lease.

(36)

Residential use area. The area within 200 feet of all boundaries of any property producing noise or, where such property is a railroad, the area within 200 feet perpendicular to the centerline of the railroad track at the source of noise, when the predominant use of properties in that area is for residential purposes.

(37)

Slow meter response. The dynamic response of a sound level meter, as specified under the most recent specification of the American National Standards Institute, Inc., New York, N.Y. (ANSI) for sound level meters.

(38)

Sound. An auditory sensation evoked by alternating compression and expansion of air, or other medium, accompanied by changes in pressure, particle velocity or displacement.

(39)

Sound level. The weighted sound pressure level in decibels obtained by use of a sound level meter with a metering response (fast or slow) and A, B or C weighting networks as specified by the American National Standards Institute, Inc., New York, N.Y. (ANSI).

(40)

Sound level meter. An instrument comprising a microphone, amplifier, and output meter, and frequency weighting networks, that is used for the measurement of sound levels in a manner specified by the American National Standards Institute, Inc., New York, N.Y. (ANSI), in its standards 1.4-1971 or latest revision.

(41)

Sound pressure. The difference between the barometric or average pressure and the instantaneous pressure created at a given point by a source of sound: measured in Newtons per square meter.

(42)

Sound pressure level (in decibels). 20 times the logarithm to the base of 10 of the ratio of the pressure of the sound being measured to a reference sound pressure of 20 micronewtons/m2(0.0002 microbars).

(43)

Sound reproduction device. A device intended primarily for the production or reproduction of sound including, but not limited to, any musical instrument, radio receiver, television, receiver, tape recorder, phonograph and sound amplifying system.

(44)

Sound signal device. A device designed to produce a sound signal when operated, including but not limited to, any klaxon, air horn, whistle, bell, gong, siren, but not an emergency signal device.

(45)

Warning device. Sound signal devices used to alert and warn people. The members of the environmental policy commission in office as of the effective date of this ordinance shall continue to serve the unexpired portion of their term of office. (Ord. No. 4152, 9/16/00, Sec. 3)