An Acoustifence barrier recently installed near a noisy exposed aerator motor at the Hillsborough County Northwest Regional Facility in Florida resulted in an immediate and significant reduction in noise pollution for neighboring residents.
The facility is part of a 1,500-acre, multi-use tract owned by Hillsborough County. It is a Type 1 advanced wastewater treatment facility (WWTF) built to process five million gallons of wastewater per day. The utility is located on a 67-acre parcel of land in Hillsborough County Florida, with a residential community located near the premises.
Last year, members of the Highland Park Residential Community voiced their complaints about loud whining noises originating from the nearby plant. The noise source was a 200-HP Carrousel vertical, high-efficiency aerator drive motor located atop the plant's 24-foot Oxidation Aeration Basin structure, according to Flint Seth, general manager of biosolids production and maintenance at the facility.
Accordingly, Doug Fisher of the Hillsborough County Public Utilities Department worked with Acoustiblok to devise an economical solution consisting of an L-shaped frame barrier secured with four 6-by-30-foot Acoustifence outdoor noise-reduction panels. Witt Fence Company of Riverview, Fla., was contacted by Hillsborough County personnel to install the barrier.
An advanced sound barrier, the Acoustifence actually flexes with certain frequencies, especially very low ones, unlike a concrete block wall. In the process of sound waves physically moving it, the product transforms sound wave energy into inaudible internal friction energy. As the Acoustifence is only 1/8 of an inch thick, it is very easy to position it closer to the noise source.
Acoustiblok Corporation's Acoustifence product is a unique proprietary formula. It is a heavy, mineral-filled viscoelastic polymer material and an effective first step in reducing noise for industrial, commercial and residential applications.
A noise meter was used to measure the difference in sound before and after the installation of the noise barrier fence at the Hillsborough facility. Typical noise from these Carrousel vertical aerator motors ranges from 80 to 83 decibels from three feet away, according to the manufacturer. From 10 feet away, the noise measured 79 decibels before installation and registered 69 decibels immediately after the fence was installed. With a 10-decibel decrease, perceived loudness to the human ear is cut in half.
Besides the proven and tested sound reduction qualities of Acoustifence, another beneficial quality of the product is that it is quick and easy to install. Installation of the sound barrier at the Hillsborough County facility took only one day, and they encountered no unexpected problems.
While the solution to the noise issue at the WWTF was not a complex one, it was an effective one for Hillsborough County. "The Acoustifence barrier made a difference, and we are very pleased with it," said Seth. "We have not received any new complaints about the motor noise since the installation of the barrier fence."
