Environmental Issues
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Noise Control
Tradewinds has committed to meet or exceed all local, state and federal regulations regarding the environment. It is a main tenant of our corporate culture to be a good neighbor—this means protecting the air, water and soils of our community.
Tradewinds will use a combination of structural components (such as sound baffles and walled enclosures), electric cranes and layout design to help reduce noise. State laws allow a noise level of 70 dB at the property line. Tradewinds has committed to achieve much lower sound levels than the limits allowed by laws. We have hired acoustical engineers to design the sound mitigation systems.
Sound mitigation measures include:
- Use of an electric crane instead of wheeled machines with diesel motors and backup alarms in the log receiving area,
- Enclosing machinery inside buildings where feasible,
- Directing all building openings toward unpopulated areas (the gulch or ocean)
- Installing sound baffles on ventilation openings as needed, and
- Installing factory designed mufflers on the boiler.
By choosing to use an electric overhead log crane, we have eliminated the need for three machines that would have been required by OSHA to use backup alarms. In Oregon and Washington it is possible to eliminate back-up alarms by using “pedestrian exclusionary” zones. We will work with the State of Hawaii to attempt to get a similar exemption for the remaining yard machine. The log receiving yard and outdoor equipment will operate only during daylight hours. Sundays will be a shutdown day except for the boiler and turbine.
How is sound measured?
Sound is measured in decibels, abbreviated dB. Human hearing ranges between 1dB and 180dB. Decibels are logarithmic units, similar to the way earthquakes are measured, so a level of 50dB is ten times as loud as 40dB. Sustained exposure to anything over 90dB without hearing protection, results in hearing damage. When several noises are generated simultaneously, the decibel levels do not equal the sum of the individual noise sources, but are only slightly higher than the loudest sound. For example, a machine generating 20dB of noise running at the same time as a machine generating 40dB actually only produces a combined noise level of 41dB, so this essentially means the sound of the quieter machine is absorbed by the sound generated by the noisier machine.
What are the legal restrictions on sound levels?
Hawaii Administrative Rules mandate a decibel level at the property boundary of no more than 70dB 24 hours a day, seven days a week. (Hawaii Administrative Rules, §11-46-4, Table 1.) Industrial facilities in Oregon and Washington must operate at 55-60dB days and 50-55dB nights, so sound reduction technology is well understood. Tradewinds has voluntarily committed to a maximum noise level of 60dB during the day and 55dB at night (as measured at the site boundary at Old Mamalahoa Highway).
How will sound levels vary over a 24-hour period?
Trucks will not be operating before 7:00 am or after 8:00 pm. There will be no truck traffic on Sundays. A small chipper will process scrap wood and non-veneer quality logs. It will run five days a week during daylight hours. The chipper will be contained in a sound-deadening building.
The dryers will run 24 hours a day, six days a week and the lathe will run for ten hours a day, five days a week. Eventually the lathe may run two shifts, which would be sixteen-hour days. The lathe and the dryers will be housed in a large building designed to reduce sound.
How does this compare with current sound levels at the site?
A stroll through town with a sound meter in May 2006 showed that the background noise level was 45 to 60dB. A dog barking two blocks away registered at 70dB. An Australian study of children in playgrounds registered between 62 and 74dB. Woodworking equipment operating at 100dB inside a building registers 50dB at 100 feet.
A good example of effective noise containment can be found at Haina, where Hamakua Energy Corp operates two LM2500 turbines inside an insulated building. These are the same engines found under the wings of 737 jets. The sound level inside the building is many times the sound energy of the loudest machine in a cogeneration plant. Hamakua Energy has installed effective sound suppression and reports that their maximum decibel level is well under the legal limit.
What is Tradewinds doing to reduce sound?
Wherever possible, Tradewinds is using equipment powered by electricity instead of diesel. The log yard has been designed to use an electric crane instead of diesel powered stackers, which also reduces the number of vehicles using federally-mandated back-up warning signals. Buildings housing noisy equipment such as the lathe and boilers will be insulated and specially designed to minimize noise. Baffles will be installed on vents and fans. Mill buildings will be oriented to channel noise towards non-populated areas (e.g., ocean and gulches). The entire mill site will be fenced and landscaped to further reduce noise levels, including masonry walls along the line of sight between noise sources and protected area if necessary. Tradewinds has retained acoustical engineers who have analyzed the site and the equipment to be used. These engineers have expressed confidence that we will be able to operate well under legal limits.
Trucks will be directed to make use of the Honokaa side cane haul road and to remain on the road above the gulch when waiting to be loaded or unloaded. The rock wall above the road will absorb and reflect noise towards the fields to the west, away from local homes.
A sound test was run at the O’okala mill site in late Spring, 2006. A sound demonstration was run and the results were at the same levels as other veneer mills. The recording ran from mid-morning until 4PM. Notices had been posted announcing the test and inviting local people to come and hear for themselves the results. At the parking lot of the Post Office (on the perimeter of the mill site) the sound was barely discernable.
Comparable Sound Levels
| Sound | Decibels | Effect | ||
|---|---|---|---|---|
| Jet Taking Off Firecracker Artillery Fire |
140 | Beyond the threshold of pain | ||
| Shotgun Fire Jet Takeoff (100-200’) Stockcar Races |
130 | Threshold of pain | ||
|
Thunderclap (close by) Ambulance Siren |
120 | Threshold of sensation | ||
| Power Saw Pneumatic Drill Baby Crying |
110 | Regular exposure exceeding 1 minute risks permanent hearing loss | ||
| Garbage Truck Car Horns Woodworking Class |
100 | Damage at 15 minutes unprotected exposure | ||
| Tractor Motorcycle Lawnmower |
90 | Very annoying | ||
| Electric Razor Heavy Traffic Noisy Restaurant |
85 | Hearing damages starts (8hrs) | ||
| Average City Traffic Garbage Disposal Alarm Clock |
80 | Interferes with conversation | ||
| Vacuum Cleaner Hair Dryer Car Interior |
70 | Interferes with conversation | ||
| Normal Conversation Sewing Machine | 60 | Comfortable | ||
| Quiet office Air Conditioner Rainfall |
50 | Quiet | ||
| Whisper | 30 | Very quiet | ||
| Normal Breathing | 10 | Just audible | ||
| Source: League for the Hard of Hearing, the Canadian Hearing Society | ||||
If I have a complaint about noise, who do I call?
We hope that if our neighbors have a complaint about Tradewinds’ operations, they will come to us first, so we can fix the problem. If you feel the need to make a formal complaint, please see the information below.
State of Hawaii Department of Health
Noise Radiation & Indoor Air Quality Branch
591 Ala Moana Boulevard
Honolulu, HI 96813
808 586-4700
State of Hawaii Administrative Rules Chapter 11-46
www.hawaii.gov/health/about/rules/11-46.pdfFor more information on sound:
Canadian Hearing Society
www.chs.ca/info/noise/levels.htmlLeague for the Hard of Hearing
www.lhh.org/noise
50 Broadway, 6th Floor
New York, NY 10004
917 395.7700University of New South Wales
Sydney, Australia
www.phys.unsw.edu.au/~jw/dB.html
Noise & Sound | Traffic |Clean Air & Water | Coqui Frogs | Plantation Forestry | Biomass Energy Advantages | Eucalyptus & The Environment