§ 17.52.030. Noise requirements.
A.
General Noise Limitations. Any business operation with sustained or intermittent noise levels exceeding seventy dB ldn (or CNEL) as described by the noise element including, but not limited to, wood or machine milling, air hammers, generators, or prolonged or excessive truck deliveries, will not be allowed within one hundred feet of residential uses, hospitals, and other noise sensitive uses unless noise levels are mitigated in compliance with this section.
B.
Operational Hours. All commercial and industrial deliveries and loud commercial activities such as loading and unloading, leaf blowers, bands with loudspeakers within one hundred feet of a residential use shall be limited to the hours between seven a.m. and ten p.m.
C.
Review Of Development Projects. The city shall review new public and private development proposals to determine conformance with the policies of the noise element. Where the development of a project may result in land uses being exposed to existing or projected future noise levels exceed the levels specified by the policies of the noise element, the city shall require an acoustical analysis early in the review process so that noise mitigation may be included in the project design. For development not subject to environmental review, the requirements for an acoustical analysis shall be implemented prior to the issuance of a building permit. The requirements for the content of an acoustical analysis are given in subsection E of this section. At the discretion of the city, the requirement for an acoustical analysis may be waived provided that all of the following conditions are met:
1.
Size of Development. The development is for less than five single-family dwellings or for office buildings, churches or meeting halls having a total gross floor area less than ten thousand square feet;
2.
Noise Source. The noise source in question consists of a single transportation noise source (roadway, railway or airport) for which up-to-date noise exposure information is available. An acoustical analysis will be required when the noise source in question is a stationary noise source or when the noise source consists of multiple transportation noise sources;
3.
Noise Exposure. The existing or projected future noise exposure at the exterior of the buildings which will contain noise sensitive uses or within proposed outdoor activity areas (other than playgrounds and parks) does not exceed sixty-five dB Ldn (or CNEL) prior to mitigation. For playgrounds and parks, the existing or projected future noise exposure may not exceed seventy-five dB Ldn (or CNEL) prior to mitigation;
4.
Topography. The topography in the project area is flat, and the noise source and receiving land use are at the same grade; and
5.
Noise Mitigation. Effective noise mitigation, as determined by the city is incorporated into the project design to reduce noise exposure to the levels specified in Table 17.52.030(1), codified at the end of this chapter. Such measures may include the use of building setbacks, building orientation, noise barriers and the standard noise mitigation packages contained within the acoustical design manual. If closed windows are required for compliance with interior noise level standards, air conditioning or a mechanical ventilation system will be required.
D.
Noise Reduction Measures Required. The planning commission shall consider one or more of the following mitigation measures where existing noise levels significantly impact existing noise sensitive land uses or where cumulative increase in noise levels resulting from the new development significantly impact noise sensitive land uses:
1.
Rerouting Traffic. Rerouting traffic, if feasible, onto streets that have low traffic volumes or onto streets that do not adjoin noise sensitive land uses;
2.
Rerouting Trucks. Rerouting trucks, if feasible, onto streets that do not adjoin noise sensitive land uses;
3.
Noise Barriers. Construction of noise barriers as long as such barriers do not significantly negatively impact coastal or scenic views; and
4.
Acoustical treatment of buildings.
E.
Requirements for an Acoustical Analysis. An acoustical analysis prepared pursuant to the noise regulations shall:
1.
Be the financial responsibility of the applicant;
2.
Be prepared by a qualified person experienced in the fields of environmental noise assessment and architectural acoustics;
3.
Include representative noise level measurements with sufficient sampling periods and locations to adequately describe local conditions. Where actual field measurements cannot be conducted, all sources of information used for calculation purposes shall be fully described. When the use being studied is a commercial use, all noise sources related to the service and maintenance of the facility shall be considered, including parking lot and landscape maintenance, refuse collection and truck loading/unloading activities;
4.
Estimate existing and projected (twenty years) noise levels in terms of the descriptors used in Tables 17.52.030(1) and (2), codified at the end of this chapter and compare those levels to the adopted policies of the noise element. Projected future noise levels shall take into account noise from planned streets, highways and road connections;
5.
Recommend appropriate mitigation to achieve compliance with the adopted policies of the noise element, giving preference to proper site planning and design over mitigation measures which require the construction of noise barriers or structural modifications to buildings which contain noise sensitive land uses;
6.
Estimate noise exposure after the prescribed mitigation measures have been implemented; and
7.
Describe a post-project assessment program which could be used to evaluate the effectiveness of the proposed mitigation measures.
(Ord. 445 § 3 (part), 1995)