Submitted by David Johnson,

Because the City of Davis is considering a revised sound ordinance, I thought it would be helpful to hear from Robert Lawson, a sound professional, who recently posted the following informative piece on Nextdoor.com.

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I am a Certified Industrial Hygienist and Certified Safety Professional with over 35 years experience taking sound level measurements and commenting on noise issues as a part of the CEQA process.

1. It is unusual, and in my opinion a bad idea, to base the City of Davis noise ordinance in large part on sound levels averaged over a 1 hour period (l eq - 60 minutes).

-- Unusual?

 - Color coded noise ordinances from several other communities with University of California campuses (Berkeley, Los Angeles, Riverside, San Diego, San Francisco, Santa Barbara) as well as from Sacramento are available at https://nonoise.org/regulation/stateregs.htm .

Unless I’m mistaken, only San Diego uses l eq - 60 minutes. Although several use a sliding scale for averaged sound levels (30 minutes to 5 minutes, based on sound levels) most of these have specific mention or provisions for impulsive noise (noise of very short duration with a sharp onset), which is the type of noise that has had much discussion lately in town in regards to recreational equipment.

 -The nonoise.org site also includes a summary review of hundreds of ordinances across the country, indicating that 60 minute averaging (l eq 60 mins) is not common in community noise ordinances.

2. It could be costly and difficult to enforce a noise ordinance largely based on average noise levels over a 60 minute period.

-- Costly/difficult to enforce?

Dear Members of the Davis City Council,

I have looked into the proposed changes to the noise ordinance, and I have investigated what the standards are in other communities. I find both the existing ordinance and the proposed ordinance lacking in the detail to make either enforceable without considerable interpretation. Even more surprisingly though, I found that what the staff reports to be very minor changes to actually be very significant changes thus requiring a more robust process before implementation.

First, I want to address the new definition of Person in the proposed rewrite of 24.01 General Provision that exempts the city.  They simply remove: "...  including any city, county, district or other public agency." this move to exempt the City from the ordinance is a significant change and creates a dubious double standard. I do not think it is appropriate to exempt the City, but at a minimum that decision needs to be better vetted.

Next I want to address averages and maximums. Clearly changing the language in 24.02.020 figure 1 from "Maximum Noise Level (dBA)" to "Average Hourly Noise Level (dBA)" is a meaningful change that alters what is covered by the ordinance. Such a significant change should be better vetted by commissions and the community before implementation.