The consulting firm Miller, Beam & Paganelli Inc. has completed its testing of the effectiveness of the sound wall that was built around the town's leaf mulcher off Beulah Road, and the results have been posted to the town Web site.
A custom silencer that had been installed around the machine in the 2004-05 mulching season had already reduced noise levels by about one-half, as measured from the nearest property line, the firm reported. The installation of the "noise attenuation barrier," a 660-foot-long, 12-foot-high wall built around three sides of the mulching area late last year, brought the average noise down further, to about one-third the original level.
At locations further from the site, the effect of the barrier is more difficult to measure because overall noise levels are influenced by background noise, the report said.
Complaints from neighbors about noise from the site began in the last few years, although the grinder has been operating there for about 15 years. Neighbors objected to the noise from the machine, as well as from trucks unloading leaves at the site.
However, the report stated, "the noise produced by occasional trucks dumping leaves at the site contributes very little to the overall daily noise exposure."
Dennis King, the town's director of Public Works, said the operation of the mulcher itself is limited to four and a half hours or less per day between the hours of 9 a.m. and 3 p.m., Monday through Friday. He said the machine runs for a total of about 40 to 60 hours per year.
The report also noted that some concern had been expressed regarding potential hearing damage on the part of the closest neighbors. However, it said, according to the Occupational Safety and Health Administration (OSHA), eight-hour exposure to an average of 85 A-weighted decibels (85 dBA) is considered the level at which hearing loss may become a risk.
"Near the property line of the Beulah noise site, average noise levels of leaf processing activity and community background noise were closer to the 50-55 dBA range," the report read. It also noted that, because the decibel scale is logarithmic, an increase of 10 decibels is experienced as a doubling in noise level.
King added that dual mufflers had been installed on the grinder, and its idle speed had been reduced.
— Mike DiCicco