Requirements for Determining and Mitigating
Non-Transportation Noise Source Impacts to Residential Properties
| TO: |
Whom
it may concern |
| DATE: |
January
15, 2004 |
| FROM: |
Steven
T. Uhlman, CIH, JD, Public Health Program Chief |
| RE: |
Requirements
for determining and mitigating non-transportation noise source
impacts to residential properties |
APPLICATION:
This document
is intended to provide guidelines for the determination of community
noise impact due to non-transportation (hereafter known as "stationary")
noise sources. Noise sources covered by this standard include,
but are not limited to: industrial facilities, mining activities,
loading dock activities, loud speakers operation, sporting events,
musical performances, well pumps, equipment, vehicles operated
off the public roadways, or any noise producing activities associated
with a permanent fixed base of operation (hereafter referred to
as the "facility"). Temporary construction activities are not
covered by the standard.
NOISE STANDARDS
FOR STATIONARY NOISE SOURCES:
Facility-related
noise, as projected to any portion of any surrounding property
containing a "habitable dwelling, hospital, school, library or
nursing home", must not exceed the following worst-case noise
levels.
A)
45 dB(A) - 10 minute noise equivalent level ("leq"), between the
hours of 10:00 p.m. to 7:00 a.m. (nighttime standard).
B)
65 dB(A) - 10 minute leq, between 7:00 a.m. and 10:00 p.m. (daytime
standard).
REQUIREMENTS
FOR DETERMINIATION OF COMMUNITY NOISE IMPACT:
-
Noise originating from operations within the facility grounds
shall be treated as "stationary" noise sources for which this
standard will apply.
-
Noise
Modeling Methodology: Noise predictions are to be made by an
engineer, acoustical consultant, or other similar professional
with experience in predicting community noise exposure using
standard methods and practices of the noise consulting industry.
-
Required
Modeling Parameters for Stationary Sources:
i. Stationary sources are to be modeled as "point" sources.
ii. Mobile point sources are to be modeled as emanating from
the acoustical centroid of the activity, or at its closest approach
to potentially impacted residential property lines, which ever
yields the worst-case results.
iii. Noise modeling for each piece of acoustically significant
equipment, process or activity must be based on Reference Noise
Levels (RNL). RNL may be obtained directly from the manufacturer
(in the case of equipment) or generated from field studies.
Regardless, the data must be representative of worst-case conditions.
Directionality of the noise source must be taken into consideration
if applicable.
iv. Predicted noise levels are to be expressed in germs of
worst-case "equivalent continuous sound levels" [or, Leq] averaged
over a ten minute period.
v. For modeling purposes, receivers are assumed to be positioned
at the property line boundary at an elevation of five feet off
the ground.
vi. Terrain conditions for modeling noise propagation:
Assumptions regarding ground effects, atmospheric absorption
and other forms of noise attenuation must be fully justified.
NOISE REPORT
FORMAT AND REQUIRED SUBMITTALS:
The noise
Consultant's findings and recommendations must be submitted for
review, and receive approval from, the Office of Industrial Hygiene.
The resulting report must incorporate the requirements above and,
at a minimum, contain the following information: a) an adequate
and accurate characterization of the current ambient noise environment;
b) a clear description of the proposed facility and its activities
including a step-by-step flow chart of manufacturing processes
if applicable; c) the identity and characterization of all acoustically
significant equipment and/or activities; d) a discussion of analytical
methodology and parameters used for noise modeling; e) a table
containing reference noise data accompanied by a detailed description
of how it was obtained; f) the facilities hours of operation;
g) a discussion of anticipated production volume, how it is expected
to change over time and how such change will effect community
noise; h) a discussion of worst-case unmitigated noise impact;
i) a discussion of mitigation (if necessary); j) a printed copy
of computer input/output (if available) or manual calculations
clearly illustrating the rationale for the Consultant's conclusions.
In addition,
the final noise report must contain a scaled map(s) defining the
acoustical contours surrounding the facility. Minimally, this
map(s) must show:
a)
The facility relative to the residential properties surrounding
it. Include both unincorporated and incorporated (any adjoining
Cities) area surrounding the project and potentially affected
by project-related noise.
b)
The 65 dB(A) 10 minute Leq noise contour reflecting the anticipated
"worst-case" conditions between the hours of 7AM - 10
PM (daytime hours).
c) The 45 dB(A) 10 minute Leq noise contour reflecting the anticipated
"worst-case" conditions between the hours of 10 PM -
7AM (nighttime hours).
d) The location and number of residential structures located within
these contours.
|
Office of Industrial Hygiene - (951) 358-5050
Lead Hazard Control Program Direct Number - 1-877-932-4100 |
Office of Industrial Hygiene
Department
of Public Health, Health Administration Building,
4065 County Circle Drive, Riverside, CA 92503
|
