[R.O. 2009 §25-451; Ord. No. 2739 §43-60, 5-20-1985; Ord. No. 4396 §1, 12-17-2012]
Every use, activity, process or operation located or occurring in the City shall comply with the environmental performance standards prescribed in this Division, and no such existing use, activity, process or operation shall be altered or modified so as to conflict with, or further conflict with, such environmental performance standards.
[R.O. 2009 §25-452; Ord. No. 2739 §43-60.1, 5-20-1985; Ord. No. 4396 §1, 12-17-2012]
A. 
Whenever, in the opinion of the Zoning Administrator, there is a reasonable probability that any use or occupancy violates these environmental performance standards, he or she shall give written notice of at least seven (7) days duration that the use or occupancy must be corrected. In case of an emergency he may take immediate action deemed appropriate to correct the violations. He or she is hereby authorized to employ a qualified technician or technicians to perform whatever investigations and analyses as are necessary to determine whether or not they are in fact being violated.
B. 
If a violation is found to exist, the violator shall be liable for the reasonable fee of the technicians employed to perform such investigations and analyses. Such fees may be recovered as a penalty in the same manner as, and in addition to, the penalties specified for violation of this Chapter.
C. 
If a complaint is received regarding an alleged violation of any of the provisions of this Division and the Zoning Administrator does not believe that there is a reasonable probability that such a violation actually exists, the Zoning Administrator may, as a condition precedent to further investigation, require that the complainant post an escrow deposit in the amount sufficient to defray the cost of employing a qualified technician to perform such investigations and analyses as may be necessary to determine whether or not such violation exists.
1. 
If the complaint is substantiated, the escrow deposit shall be refunded to the depositor, and the reasonable fees associated with the investigations and analyses shall be recovered in the manner provided above.
2. 
If the complaint proves unfounded, such fee shall be paid from the complainant's escrow deposit. Any remainder of such deposit shall be refunded to the complainant upon completion of the investigation.
D. 
Any violation of this Division shall hereby be considered as creating a public nuisance. Therefore, in addition to the enforcement procedures specified in Sections of this Division, the regulations of Chapter 220 and any other applicable ordinance shall apply.
[Ord. No. 4396 §1, 12-17-2012]
A. 
For purposes of this Chapter, the following words and phrases are herein defined:
A-WEIGHTED SOUND PRESSURE LEVEL
A weighted sound pressure level as measured with the A-weighting network of a sound level meter. The unit of measurement is dB(A).
AMBIENT NOISE LEVEL
The A-weighted sound pressure level of all the encompassing noise associated with a given environment, being usually a composite of sounds from many sources.
A.N.S.I
The American National Standards Institute or its successor bodies.
BOUNDARY
The line of demarcation which separates the real property owned by one person from that owned by another person.
COMMERCIAL LAND USE CATEGORY
Any activity which exists on or is applied to land or structures on the land wherein goods, services or commodities are provided, exchanged or purchased and sold at wholesale or retail. The commercial land use category shall include facilities for the repair or servicing of new and used automobiles, trucks, trailers, construction equipment, agricultural equipment and boats, and public or private utility facilities.
CONSTRUCTION ACTIVITY
Any or all activity necessary or incidental to the erection, demolition, assembling, repairing, altering, installing or equipping of public or private buildings, private or public parks, premises, utility lines, and private or public highways, roads or streets, including land clearing, grading, excavating and filling.
CONSTRUCTION DEVICE
Any device used in construction including, but not limited to, any air compressor, pile driver, manual tool, bulldozer, pneumatic hammer, steam shovel, derrick, crane, steam or electric hoist.
DAYTIME HOURS
7:00 o'clock a.m. to 10:00 o'clock p.m., prevailing local time.
DISCRETE TONE
A noise measured on a one-third octave band analyzer which is ten (10) decibels greater than each of the adjacent one-third octave bands.
EMERGENCY WORK
Work necessary to restore property to a safe condition following a public calamity, or work required to protect person or property from an imminent exposure to danger.
EMERGENCY SIGNAL DEVICE
Any gong, siren, whistle or any air horn or similar device when used on any vehicle designated as an emergency vehicle by ordinance or by Missouri statute, or used in connection with an emergency warning system, or used in connection with a warning system intended to produce a sound signal upon unauthorized entrance by a person into a building or motor vehicle.
IMPULSIVE NOISE
A noise, containing excursions usually of no more than one second, the A-weighted sound pressure level of which exceeds the ambient noise level by more than twenty (20) dB(A), when measured by the fast meter characteristic of a sound level meter.
MOTOR VEHICLE
Any self-propelled vehicle not operated exclusively on rails.
PERCEPTION THRESHOLD
The minimum vibrational motion necessary to cause awareness of the existence of the vibration by direct means, including, but not limited to, sensation by touch or visual observations. Any vibration which produces more than five-tenths (0.5) inch/second root mean square vertical velocity shall be deemed sufficient to cause the awareness of the existence of the vibration by direct means.
PERIOD OF MEASUREMENT
Any continuous sixty-minute period during which observations of stationary noise sources are made and measurements of noise levels are taken.
PERSON
Any human being, firm, association, organization, partnership, business, trust, corporation, company, contractor, supplier, installer, user, owner, or operator and shall include any municipal corporation or its officers or employees.
SOUND
An audible oscillation of pressure in air.
SOUND LEVEL METER
Any instrument including a microphone, an amplifier, an output meter, and frequency weighting networks for the measurement of sound pressure levels in a specified manner which complies with Type 2 or better standards established in the A.N.S.I. S1.4-1971 "Specification for Sound Level Meters".
SOUND PRESSURE LEVEL
Twenty times the logarithm to the base 10 of the ratio of the root mean square pressure of a sound to the standard reference pressure which is twenty (20) micropascals. The unit of measurement is the decibel (dB).
STATIONARY NOISE SOURCE
Any equipment, motor vehicle, aircraft, or facility, fixed or movable, capable of emitting audible sound.
VEHICULAR WAY
A paved or unpaved area used by motor vehicles including, but not limited to, roads, streets, highways, alleys and parking lots.
VIBRATION
A spatial oscillation of displacement, velocity or acceleration in a solid material.
B. 
Applicability Of Standards Established By A.N.S.I. The acoustical terminology, the reference pressure, instrument specifications, and calibrations and methods for measurement of sound pressure levels shall be in conformance with the definitions and provisions contained in the documents designated as A.N.S.I. S1.1-1971, S.4-1971, S1.11-1966 (R 1971) and S1.13-1971, of which one copy of each document is filed in the office of the city clerk/ administrator and Brentwood public library.
[R.O. 2009 §25-453; Ord. No. 2739 §43-60.2, 5-20-1985; Ord. No. 4396 §1, 12-17-2012]
A. 
No person shall operate or permit to be operated any stationary noise source which emits noise in such a manner that the level of the noise emitted, when measured at any point outside the boundary of the property upon which the stationary noise source is located using the slow meter characteristic and the A-weighting network of the sound level meter, exceeds the levels set forth in Table below.
B. 
If the stationary noise source emits noise containing a discrete tone, the permissible levels shall be 5dB lower than the applicable levels of Table.
C. 
If the stationary noise source emits impulsive noise, the levels of Table shall be lowered by 5dB. A violation of this Code shall exist if the level of the impulsive noise emitted exceeds the applicable levels of Table, as modified by this Subsection, when the measurement is made using the fast meter characteristic and the A-weighting network of the sound level meter or if the level of the impulsive noise emitted exceeds the limit set forth in Table.
D. 
In the event the stationary noise source emits impulsive noise containing a discrete tone, the modifications of Table set forth in Subsections (B) and (C) herein shall be cumulative.
E. 
If the ambient noise level exceeds the level of the noise emitted from the stationary noise source for one or more periods of time during the period of measurement, then for any such period of time the level of the noise emitted from the stationary noise source shall be deemed to be lower than the level which is permitted for sixty (60) minutes during the period of measurement.
F. 
If, during the period of measurement, noise shall be emitted from a stationary noise source for periods of time at two (2) or more different levels, a violation of this Code shall exist if the sum of the following fractions C1/T1 + C2/T2 + Cn/Tn exceeds the unit number 1. For purposes of this calculation Cn shall equal the actual time period that noise is emitted at each measured noise level and Tn shall equal the period of time that noise is permitted under Table to be emitted at each measured noise level. Provided however, if:
1. 
The ambient noise level exceeds the level of noise emitted from the stationary noise source for one or more periods of time during the period of measurement; or
2. 
The level of the noise emitted from the stationary noise source is lower than the level of noise which is permitted in Table for sixty (60) minutes during the period of measurement in the applicable land use category and for the applicable time of day for one or more periods of time during the period of measurement, then for the purpose of the calculation set forth in this Subsection, for each such period of time, the term Cn shall be deemed to be zero (0) and the fraction ;frax;Cn;Tn; shall be zero (0).
ALL PROPERTY CATEGORIES — DAYTIME HOURS
Tn* (Time)
(dB(A))**
60
55 or less
30
56 — 58
15
59 — 61
8
62 — 64
4
65 — 67
2
68 — 70
0
71 or greater
ALL PROPERTY CATEGORIES — NIGHTIME HOURS
Tn* (Time)
(dB(A))**
60
50
30
51 — 53
15
54 — 56
8
57 — 59
4
60 — 62
2
63 — 65
0
66 or greater
G. 
Exceptions. To the extent provided in this Section, the provisions of this Chapter shall not apply to:
1. 
The operation of construction devices, with sound control devices equivalent to or better than the original equipment, used in construction activities during daytime hours.
2. 
The repair, maintenance or construction of public facilities of the State, County or municipal governments, or such public or quasi-public municipal corporations as may be established under the Constitution or laws of the State of Missouri.
3. 
Emergency work to repair or maintain private utility facilities.
4. 
Emergency work to repair equipment or facilities damaged or rendered inoperable as a direct result of unavoidable upset conditions providing such occurrence is reported to the Director within twenty-four (24) hours after the occurrence.
5. 
The operation of motor vehicles on a vehicular way with such control devices equivalent to or better than the original equipment.
6. 
The operation of railway equipment and vehicles operated exclusively on rails.
7. 
The necessary operation of emergency signal devices.
8. 
Electric power distribution transformers within a distance of fifty (50) feet from the base of the support pole or from the fence line.
9. 
The operation of lawn care maintenance equipment with sound control devices equivalent to or better than original equipment from 7:00 A.M. prevailing local time to sunset on weekdays and 8:00 A.M. prevailing local time to sunset on weekends.
[R.O. 2009 §25-454; Ord. No. 2739 §43-60.3, 5-20-1985]
A. 
Any use, process, operation or activity which shall cause at any time and at any point beyond the boundaries of the lot, earthborn vibrations, other than background vibrations produced by some source not under control of this Division, such as the operation of motor vehicles or other transportation facilities, in excess of the limits set forth in the following table is prohibited. Vibration shall be expressed as displacement in inches and shall be measured with a three (3) component measuring system approved by the Building Official.
Frequency in Cycles per Second
Displacement in Inches
0 to 10
.0004
10 to 20
.0002
Over 20
.0001
B. 
Impact vibrations which are discreet pulses that do not exceed one hundred (100) impulses per minute shall be permitted twice the displacements shown above.
[R.O. 2009 §25-455; Ord. No. 2739 §43-60.4, 5-20-1985]
No use shall discharge or store within or beyond its lot or site boundaries any toxic matter in such concentrations as to be detrimental to or endanger the public health, safety, comfort or welfare or cause injury or damage to property or business.
[R.O. 2009 §25-457; Ord. No. 2739 §43-60.6, 5-20-1985]
Any operation producing glare or heat shall be performed within a completely enclosed building in such manner as not to create a public nuisance or hazard beyond the boundaries of the lot on which such building is located.