NOISE!

November 5, 2002 Noise Ordinance DRAFT as issued, without comments

On November 5, 2002 the Healdsburg Planning Department issued the long awaited Draft Noise Ordinance. A complete digital copy is provided here. You can download this document to your computer for reference, or to annotate and provide your input to the Healdsburg Planning Department.

How the Christmas Faerie tried to give a present to each and every one.

ourHealdsburg.com REVIEW, commentary, and suggested revisions to the Nov. 5 DRAFT.

The DRAFT Noise Ordinance REVIEW SUMMARY

Noise: The word noise is believed to be derived from the Latin word "nausea," meaning seasickness. Etymologically the word can be traced back to Old French (noyse) and to 11th century Provençal (noysa, nosa, nausa), but its origin is uncertain. Physically, there is no distinction between sound and noise. Sound is a sensory perception and the complex pattern of sound waves is labeled noise, music, speech etc. Noise is thus defined as unwanted sound. Sound Pollution is an imbalance in a Soundscape caused by intruding or disrupting sound of any kind.

Sound travels in waves through the air like waves through water. The higher the wave, the greater its power. The greater the number of waves a sound has, the greater is its frequency or pitch.

The strength of sound, or sound level, is measured in decibels (dB). Sound is measured with a Sound Level Meter.

Frequency is measured in Hertz (Hz) (cycles per second).

Normal human hearing ranges from 20 Hz to 20,000 Hz or, roughly, from the lowest note on a great pipe organ to the highest note on a violin. The human ear has different sensitivities to different frequencies, being least sensitive to extremely high and extremely low frequencies. Our ears hear very low and very high pitched sounds more faintly than those sounds in our normal conversation pitch, between 300 and 4,000 Hz.

Because of this varied sensitivity, the term "A Weighting" is used: all the different frequencies, that make up the sound, are assessed to give a sound pressure level. This is expressed as dB(A).

The decibel scale is logarithmic (based on powers of ten), not linear like a ruler. Therefore, a small increase in decibels represents a great increase in intensity. For example, while 10 decibels is 10 times more intense that one decibel, 20 decibels is 100 times more intense (10 X 10, rather than 10 + 10), 30 decibels is 1,000 times more intense (10 X 10 X 10), and so on. The sound intensity multiplies by 10 with every 10-decibel increase. The reason for such a scale is simply that the human ear is sensitive over such a wide range of acoustic energy that the numbers involved had to be compressed for convenience. See Sound Level Comparison table.

In some ways, the decibel scale resembles the Richter scale for earthquakes. A small numerical increase represents a great increase in intensity. The ear can detect a very slight change in noise intensity. Even a small reduction in decibels then can make a difference in a noise ordinance.

This discussion is a little technical but don't let that scare you. It really isn't "rocket science". Just take it one step at a time.

Many cities around the world are trying to deal with environmental pollution, including noise. Polluting the environment is not a right. Our effort to reduce sound pollution is similar to other efforts to reduce pollution, whether the issue is second-hand smoke, harmful automobile emissions, or ground level ozone, the goal is to protect the environment and our health and well-being.

Controlling sound pollution in outdoor Healdsburg residential areas, (including backyards, patios, and parks, and open bedroom windows at night), is very important because - quiet, is the fundamental basis for their use. (Table of Comparison of sound levels.)

Healdsburg's noise regulations, have not kept pace with the growth of the town. They are poorly defined, inconsistent, full of noncompliance loopholes, exemptions, exceptions and variances. A new Healdsburg noise ordinance must eliminate these faults.

A sound level comparison of common noises is a good place to start understanding sound and sound levels. One must consider many different characteristics to describe environmental noises completely.

Measuring these sound characteristics is done using a sound level meter.

Various types of modern sound level meters will not only measure sound levels, but sound levels over various time periods, peak levels, rate of change, frequency, and cumulative sound levels over time. This is the essential tool in monitoring and enforcing any noise regulation.

EPA studies have shown: as is common with annoyance and interference caused by noise, the effects of context and situation may be almost as important as the magnitude or intensity of the source. Several factors beyond the magnitude of exposure have been found to influence community reaction. These factors include:

Thus, in total there is a very complex multidimensional relationship between the various characteristics of the environmental noise and the effects it has on people. Unfortunately, we do not completely understand all of the complex links between noise characteristics and the resulting effects on people. It is difficult to describe exactly what is noise for each person, it's a bit like pornography "I know it when I hear it".

The potential for conflict occurs when Industrial or other potential noise sources are located near Residential Zones. For Healdsburg this potential is generally located in a narrow band along Healdsburg Avenue. See: Healdsburg Zoning map (PDF)

Very sophisticated noise maps

can be made for monitoring and enforcement uses. We need one!

The ideal noise ordinance defines an invisible wall between adjacent land use (noise) zones. Each zone is assigned a maximum noise level permitted for certain time periods such as day/night, weekday/weekend. Noise, either generated in the zone, or received after passing through that invisible wall from another zone, cannot exceed the noise level established for the Receiving Land Use zone.

It is the responsibility of the noise producing source to mitigate the nonconforming noise, not the Receiving Zone. If you are responsible for a business already receiving complaints from neighbors about excessive noise, you already know you have a problem. Better get busy finding solutions. Bending the noise ordinance, or attempting to add a special loophole is not the route.

Ambient noise level is a significant issue when measuring noise outdoors. Special techniques for determining the ambient noise level are required to effectively establish a noncompliant noise source.

In general, the more a noise exceeds the previously existing ambient noise level, the less acceptable the new noise will be judged by those hearing it.

Sound transmission outdoors is highly dependent on weather conditions including temperature, humidity and wind. For example Syar's Sand and Gravel plant with many noise generating loaders, conveyors, crushers, asphalt plants is adjacent to the Russian River, ideal for sound reflections, it has no physical sound barriers, and frequent winds from the south create ideal conditions for broadcasting noise and dust across adjacent residential and park areas. One thing is clear, unless these weather condition issues are addressed in the new Healdsburg Noise Ordinance meaningful enforcement will be difficult.

The types of uses which typically produce the noise sources described above include but are not limited to: industrial facilities including lumber mills, trucking operations, tire shops, auto maintenance shops, metal fabricating shops, shopping centers, drive-up windows, car washes, loading docks, public works projects, recycling centers, electric generating sub-stations, athletic fields, construction, and alcoholic beverage establishments.

A significant source of ambient noise is transportation and traffic related. Upcoming community meetings will provide an opportunity to consider the impacts a new noise ordinance will have on these sources and vice versa.

The UK has established noise guidance for outdoor mining operations comparable to Syar's Industries Healdsburg operations. Minerals Planning Guidance: The control of noise at surface mineral workings, MPG 11 (April 1993) Keeping in mind this is a government document tilted to favor industry, it provides some useful insights for developing a new Healdsburg noise ordinance. For example Daytime operating hours are 7am to 7pm. Recommended noise levels are established at a maximum of 10 dB(A) over ambient with a daytime limit of 55 dB(A) LAeq,1h (this is the sound level in dB(A) averaged over a period of time, in this case 1 hour), and a nighttime nominal limit of 42 dB LAeq,1h These noise limits are not intended to become the norm, but maximum levels. The guidance also states: "However, there may be a need to modify" (LOWER) "the nominal limit in the light of local circumstances."

Other areas discussed include equipment back up signals and hauling trucks. "Noise from off-site traffic related to a minerals

operation can sometimes cause as much, if not more, annoyance as the noise from the operation itself." An excellent reference.

Current noise ordinance practice is to reduce the assessment of environmental noise to a small number of quite simple quantities that are known to be reasonably well related to the effects of noise on people (LAeq,T for continuing sounds and LAmax or SEL where there are a small number of distinct noise events).

These simple measures have the distinct advantage that they are relatively easy and inexpensive to obtain and hence are more likely to be widely adopted.

The newest type of ordinance uses a Statistical Parameters Ln, or a sound level which cannot be exceeded in a percent of time. This method is sometimes called a "Tiered Level". This is a very appealing method for Healdsburg. The difficulty arises with this type of ordinance in the interpretation of the noise level once it has been measured and any penalty for the character of the noise has been added to the measured level.