The following information is meant to educate you to the potential noise impacts of hard-rock quarries, asphalt and concrete plants.
Noise generated by a quarry operation will continue over the life of the quarry. This noise comes from blasting, stone crushers, truck traffic, bulldozers, loaders, and general noise from the operation of multiple plants within the quarry operation. This section covers information about noise pollution and its impact on the surrounding residential and school environments.
One form of pollution that is characteristic of industrial societies is noise. Quarry operations must comply with federal and state noise regulations. However, historically surrounding neighbors of quarries find that noise is almost always a major problem.
The intensity of sound is measured in units known as decibels (dB). At a level of 80 decibels, sound is annoying; but steady exposure to noise in excess of 90 decibels—a level that is frequently exceeded by many common urban sounds, such as jackhammers, heavy machinery, jet planes, and excessively loud music—can cause permanent loss of hearing.
Explosives are placed into holes drilled in the rock and in a series of timed explosions large areas of rock face are shattered to enable extraction and crushing. Blasting is essential for ongoing rock extraction.
A rush of air that moves out from the blast site accompanies each explosion. Limits are set for the force that can be experienced at neighboring properties.
Explosions shake the ground for some distance around the blast site. Residential properties around the quarry may experience significant increases in the effects of blasts. These will suffer loss of amenity as a result of these increased effects. These effects will continue for the life of the quarry 30-50 years into the future.
Within the quarry itself a number of pieces of plant emit penetrating discrete sounds. Rock breakers are a strong percussive noise that has been commonly mentioned by disturbed residents. The stone crushers that constantly crush the extracted rock into smaller and smaller fragments make continuous noise. These give off a loud and penetrating drone.
Truck traffic makes varying noise levels. Haul trucks and loaders within the quarry are on the move continually during operations. Transport trucks arrive empty and are filled. Filling often results in loud crashes and thumps as empty metal bins are loaded. All trucks and mobile plants have loud and penetrating reversing beepers that may be a constant nuisance to local residents.