The Bradley Landfill & Recycling Center, a division of Waste Management, recently finished the acoustic retrofit of its Bradley Generation Facility located in Sun Valley, California, U.S.A. The acoustic retrofit contract was awarded to the Calgary, Alberta, Canada firm of ATCO Noise Management. As part of the overall turn-key retrofit project, ATCO designed, supplied and installed acoustic equipment enclosures and acoustically treated the exhaust mufflers and ventilation fans of the generating buildings. “While we perform many retrofit projects each year, this project is the first waste-to-energy facility we’ve worked on,” said Boris Rassin, president, ATCO Noise Management. “With the push for green energy intensifying, this industry represents a new area of business opportunity for our company.”

The Bradley Generation Facility project was designated as a green energy initiative undertaken by Bradley Landfill & Recycling Center. The facility is located adjacent to a residential neighborhood and the acoustic treatments undertaken by ATCO are designed to meet the 30 decibel (A-weighted) noise level target−the level of noise normally heard in a forested, rural location.


The Waste Management engineering group search identified some of the premier noise mitigation companies and further investigation, together with referrals from respected major companies, lead to selection of ATCO for this project according to Mike Williams, municipal marketing for Waste Management.

“The generating plant was operating within all regulatory requirements,” said Williams. “Waste Management became concerned that, although within requirements of the regulations, the neighborhoods nearby were still bothered by the low frequency noise of the plant. These concerns lead to more noise testing and resulted in the retrofit by ATCO to implement noise mitigation to the maximum extent technologically possible as a good neighbor in the community.”

The facility uses five electric generator sets powered by Deutz model GX1350 gas engines. The generator sets, as well as the landfill gas treatment skids that are primarily used to remove any liquid content prior to feeding the engines, was packaged by Stewart & Stevenson. The engines are configured to burn the methane gas produced by the land fill site’s decomposing trash. Each engine drives a 4160 a.c., 3 phase, 60 Hz generator and with an output of 1358 kWe at ISO 3046/1. The facility can produce a total of 6.5 MW of electricity, enough to supply 6000 to 7000 homes within the area. The facility operates continuously and provides electricity not only for the site, but for the local grid.

There were several challenges for ATCO with this project. One was the fact that each of the five engines was packaged separately necessitating the separate application of the acoustic measures to each generator set enclosure, rather than applying one common acoustical building or large barrier. The other concern was the possibility of the ground settling. “As the facility was built on an inactive portion of the landfill, extensive design consideration was required to address the potential for settlement,” said Williams.

ATCO Noise Management is a full-service engineering and construction company that provides turnkey noise control for industrial facilities around the world. The company is headquartered in Calgary, Alberta, Canada and has branch offices in Brazil, the United Kingdom and the U.S. The company also has local representation in Italy, Spain, Israel and Mexico.

Over the past dozen years, ATCO has utilized its proprietary acoustical technology to create some of the quietest industrial structures. The technology consists of 25 acoustical “sandwich” wall and roof assemblies tested in the field and at laboratories accredited by the ASTM (American Society of Testing Materials), CSA (Canadian Standards Association), and ISO (International Standards Organization). Despite their lightness of weight, the assemblies provide superior acoustic performance in the lower frequency noise.


The company uses what it refers to as its Balanced Design approach in the development of its noise reduction solutions. This approach was used at the Bradley Generation Facility. With this iterative approach, all relevant noise sources, plant and equipment layout, climatic conditions and even the local topography are analyzed with computers to determine the most effective and economical solution for a client’s needs. ATCO’s extensive cost database of various acoustical measures, compiled over hundreds of successful projects, is utilized in selecting the final solution.


Acoustic structures by ATCO range from small, on-site reciprocating engine or turbo compressor enclosures to large power plant facilities. Recently, the company designed, supplied and installed an acoustical enclosure for the Spalding Energy Center in the U.K. that measured 130 m long by 37 m high, the tallest acoustical envelope the company has developed. The stringent project noise target demanded the use of one of the company’s highest performing assemblies, which has a standard transmission class rating of 60 in conjunction with custom-designed ventilation silencers and free-standing barriers.

In addition to enclosures and buildings, ATCO can custom-design, supply and install acoustic barriers, acoustic ventilation systems, combustion air intake and exhaust silencers, acoustic doors and auxiliary building systems.