I am not about to compose a post vilifying the American industrial complex; I’m only expressing the attitude of many people that I come across who live near a noisy factory, processing plant, scrap yard, or other type of industrial facility. Perhaps in some cases, criticism by nearby residents is justified, but usually it is not, and often it is avoidable. Multiple times every year I am called in to assess industrial noise and vibration emissions to residential communities. Often I am hired by the company, sometimes by the local government, and occasionally by a residential group. And by the time I get involved, edgy relations have frequently devolved into contentious confrontations, accusations of purposeful illegalities, and claims of ill health due to noise.
During a particularly contentious community meeting that I attended last year, I received the following comments:
- “Ever since they started-up I’ve been getting sicker. Now I can’t work. Who will pay my medical bills?”
- “We invested our life savings in our house. It’s all we have. Their vibrations are cracking the walls and destroying our house. We worked hard for 40 years, and they’re stealing everything from us.”
- “I can’t sleep at night because of the noise. Are you telling us that they aren’t breaking the law?”
Let me point out at this juncture that many of these residents lived several miles from the facility, within a couple hundred feet of a busy freight railway, and that this particular industrial facility did not operate at night!
When the facility was operating during the daytime, it was possible to hear the noise throughout much of the neighborhood, prevalently in some locations, but as a dim-but-noticeable background noise in most cases. At Acoustics By Design, our objective noise and vibration measurements showed that noise levels in residential properties adjacent to the facility did in fact exceed the local noise ordinance by a small amount. However, there was no evidence that vibration from the facility was in violation, and for the vast majority of the upset neighborhood, the noise level was well below the requirements. The facility may have been able to mitigate the noise sufficiently to meet the local noise ordinance at the adjacent residential properties, but they are no longer in business.
In my mind, there are several lessons to be learned from this case. The first is for any industrial facility to be wary of locating in an industrially zoned location if that location is adjacent to a single-family residential zoning. People don’t like living next to industrial facilities, and even if the facility complies with all the regulations, an organized community can create a long-term headache for the company.
The second lesson is that companies need to consider potential noise and vibration emissions when evaluating new equipment for a facility near a residential zone, and they need to consult a noise and vibration expert early on in the process.
Finally, in some situations, companies should consider self-imposing noise and vibration limitations that are more stringent than those set forth by the local or state authorities. Many large cities and some states, such as Illinois, have well defined and reasonably stringent noise regulations. However, noise policies in many parts of the country, including the case described above, are poorly defined or lax. A lack of regulations may seem like a plus for an industrial facility, but it does not prevent a residential community from rallying local politicians and news media and creating headaches for company management. Well defined noise criteria often limit nighttime emissions to an average level of 40 or 45 dBA at residential property lines and daytime average levels to between 50 and 60 dBA. They establish limits for maximum as well as average noise levels, and they adjust the limits when the noise is tonal. They also consider existing ambient sound levels in the residential community.
Doing your homework ahead of time can save your business a lot of headaches in the long run, and it just may be the only good way to keep the local residents quiet and content. We’re a society that loves labeling things, and if your business gets labeled a “noisy demon” by the local residents, it can be a hard label to shake off. Your company’s reputation can be damaged even if you’re able to prove your innocence, because in the minds of your neighbors: perception is reality.
You couldn’t be more correct in warning a facility manager to put in the extra effort concerning sound remediation design in relation to nearby residential use. I live across the street from a new hospital addition, and the design team placed the new rotary screw chillers on the roof, facing the primary residential area, screened only by louvers. It is loud to say the least, and on 24/7. After the chillers were turned on just before the 4th of July this summer, neighbors started complaining. The architect/general contractor and the hospital admininistrator claim the sound is currently within code. The local newspaper had a front page story on “the hum”. The hospital eventually hired an independent acoustic engineer to perform studies, and “prove” the sound level is “to code”. The studies have yet to be released to the public. If the sound actually is above the threshold, the hospital executive claimed they will only remediate the noise to “code”, which is arguably dificult to monitor, as the independent study was performed on a cool day/night, with smaller loads on the two chillers. In the meantime, neighbors are organizing to get the remediation done, and possibly change the building/zoning codes to address “chillers”. The implied position of the hospital that it is “within code” has made this a “political football” in the community and neighborhood reaction towards the hospital and its 100 plus shareholder doctors is/will be a headache for all.
Bill Stenz, Registered Architect
South Bend, Indiana
Update:
The noise monitoring indicated the chillers did exceed the noise limits in the 1000, 2000, 4000Hz and >4000 Hz octave bands, although there is evidence suggesting traffic contributes to some of this. The positioning of the chillers on the rooftop, in particular one that is “parrallel” to the street, contributes more noise than the “perpendicular” chiller. Additional insulating sound blankets have been proposed, with installation and further testing to be performed next spring/summer.
Bill Stenz
Is there any update on this blog post. I am really interested.
Super, if you’re experiencing a specific noise issue, give us a call. We’d be happy to discuss it over the phone. Thanks. – Thom Thelen, Acoustics By Design, (616)241-5810.
Sure thing.