SELECTED PROJECTS:

Bremerton Housing Authority Landfill Gas Collection System

(Bremerton, WA)  The Bremerton Housing Authority is currently conducting an 83-acre redevelopment project in Bremerton, Washington. The former Westpark Public housing area is being redeveloped to include mixed-use retail buildings, public housing, and open space. A closed landfill of approximately three acres in size is located beneath one area of the redevelopment site. In May of 2012, Bremerton Housing Authority was awarded a $200,000 Brownfields Cleanup Grant from the U.S. Environmental Protection Agency (EPA) to fund design and installation of a landfill gas (LFG) mitigation system to allow safe redevelopment of this area. The Bay Vista redevelopment could not proceed in close proximity to Periwinkle Park as envisioned without an effective and affordable landfill gas control system.

A previous conceptual design prepared for Bremerton Housing Authority recommended individual methane mitigation systems for each building near Periwinkle Park, which was estimated to cost $10,000 to $30,000 per building. Another recommendation included installation of an active gas control system to extract landfill gas which had migrated into soils surrounding the landfill and prevent future migration. Bremerton Housing Authority and private developers were eager to build near the landfill, using a source control approach so that individual building mitigation systems would not be required.

Landau Associates designed and implemented a mitigation system that included installing a hybrid LFG control system. The system prevents LFG from accumulating to concentrations of concern or posing migration risks by capturing, treating, and ventilating LFG to the atmosphere. The system does not require individual mitigation systems to be installed at each building in proximity to Periwinkle Park. The system has been successfully mitigating landfill gas since 2013, and has provided the monitoring data required by the local Health District to allow Bremerton Housing Authority to build on the property surrounding Periwinkle, without the expense of installing individual mitigation systems at each building.

The project has returned the land to a usable condition and met Bremerton Housing Authority's development schedule. The system was designed and constructed within the limited funding available to Bremerton Housing Authority by the strategic use of design efficiencies and recycling remediation equipment. All the work was completed on time, within budget, and to the satisfaction of Bremerton Housing Authority and regulatory agencies.

The project was awarded an Engineering Excellence Award by the American Council of Engineering Companies (ACEC)—Washington.