GENERAL PLAN AND NOISE ORDINANCE PROVISIONS
G
eneral Plan Noise Policy
T
he Health and Safety Policy of the City’s General Plan recognizes that different land uses will tolerate different noise levels. The General Plan incorporates the Compatibility for Community Noise Environments table which contains a sliding scale noise metric depending on the type of land use, type of construction and noise mitigation. Based on this table, 60 dB is normally acceptable in residential areas and up to 75 dB with noise insulation measures. The normally acceptable noise level in business districts is 70 dB and up to 80 dB with noise insulation measures.
C
ity of Alameda Noise Ordinance
T
he City’s noise ordinance is more specific than the standards of the General Plan and thus it chiefly controls this appeal. Chapter IV of Alameda’s Municipal Code includes noise control regulations addressing the compatibility of neighborhood noise sources that may affect other receptors nearby, measured in decibels (dB) on an “A -weighted” scale to reflect the response of the human ear. (There is also a “C -weighted” scale that reflects the effect of low-frequency soundwaves that can be experienced as vibrations.) A
MC Chapter 4-10.4 provides that exterior noise levels when measured at any receiving single or multiple family residential, school, hospital, church, public library or commercial property situated in the City do not conform to the provisions of this subsection when they exceed the noise level standards set forth in Table 4.11-2 and Table 4.11-3, as follows:
Exhibit 5
According to the Noise Ordinance, residential properties (defined as defined as a parcel of real property which is developed and used solely for residential purposes) should not be exposed to daytime noise levels in excess of 55 dB over the course of a typical half - hour and commercial properties no more than 65 dB over the same time period. Noise exposure may be allowed to be higher, but only for shorter time periods, e.g. up to 65 dB for residential and 75 dB for commercial for any five-minute period in an hour.
Music has an even lower noise limit due to the distinct content of the noise which can be especially distracting. Standards are therefore reduced by five (5) dB if the noise source is music.
In the event the measured ambient noise level exceeds the applicable noise level standard in any category above, the applicable standards shall be adjusted so as to equal said ambient noise level. Ambient noise level is defined as the all encompassing noise level associated with a given environment, being a composite of sounds from all sources, excluding the noise in question, at the location and approximate time at which a comparison with the noise in question is to be made.
Synthesizing both the General Plan Noise Policy and the Noise Ordinance, the Noise Ordinance caveats discussed above and measurements of ambient noise levels around the project, staff believes the most appropriate way to analyze the applicable noise standard is to use the ambient noise level on Park Street during the day (i.e. 69 dB) and apply a 5 dB penalty due to the noise source being primarily music, resulting in a 64 dB noise limit in both residential and commercial zones. Admittedly, staff’s interpretation has evolved since the Planning Board heard the item. This evolution is based on a variety of factors including: actual noise measurements taken by staff, the unique noise impacts of prolonged, stationary music, consultation with a noise expert, the sensitivity of the location for noise impacts on residences and the analysis of prior precedent. While a few prior decisions have permitted projects to vary from the noise ordinance if the appropriate Use Permit findings could be made, staff believes the better practice is to adhere to the noise ordinance limits unless expressly authorized by another Code provision.
CEQA Noise Analysis
The City’s General Plan Health and Safety Policy HS -60 specifies when a noise impact is considered significant under the California Environmental Quality Act (CEQA):
Significant CEQA Impacts. In making a determination of impact under the CEQA, consider the following impacts to be “significant” if the proposed project causes:
an increase in the day -night average sound level (Ldn) of four (4) or more dBA if the resulting noise level would exceed that described as “normally acceptable” for the affected land use, as indicated by State guidelines, or any increase in Ldn of six (6) dBA or more.
The City’s General Plan estimates sound levels between 65 and 70 db (CNEL) on Park Street and 60-65 dB (CNEL) on streets like San Jose. Therefore, a change of 4 dB over the existing noise environment would be a significant impact under this criterion.