Home Depot USA, Inc. (Home Depot) is continually expanding into new territories through development of key property locations that meet their market demographic requirements and fit their site development model. Home Depot has substantial experience in converting closed landfill sites and other environmentally-impacted properties into productive store locations. In Oregon City, Oregon, Home Depot identified a site that is located above a portion of the closed Rossman's Landfill, which was operated between 1969 and 1983 and received residential and commercial wastes. A primary requirement for the redevelopment of the site was protection of customers and employees from potential risks associated with landfill gas (principally, methane, carbon dioxide, and trace gases). The project approach utilized by Home Depot involved design and installation of a gas monitoring and control system in compliance with Oregon Department of Environmental Quality (ODEQ) regulations.
Geosyntec's Scope of Services
Based on previous successful projects with Geosyntec related to environmentally-impacted property development and design and construction of building vapor protection systems, Home Depot selected Geosyntec to work with their design team to integrate a gas monitoring and control system into the overall site development design.
Geosyntec designed a gas monitoring and control system consisting of a spray-applied geomembrane barrier layer, continuous gas collection layer, manual gas monitoring probes, and automated gas monitoring system. We submitted our design and permitting package, including technical specifications, construction drawings, and a construction quality assurance (CQA) plan, to ODEQ which approved the submittals with minimal comments and issued a permit for construction.
Geosyntec provided CQA services during the installation of the system components to ensure that the installation conformed to the project construction documents and permit requirements. Geosyntec prepared a final CQA report documenting the installation of the system components for ODEQ acceptance.
In addition, Geosyntec prepared an Operation, Maintenance, and Monitoring (OMM) Plan for the system. Geosyntec provides ongoing support and on-call services for the OMM Plan and prepares the annual reports required by ODEQ.
Geosyntec worked with the Home Depot project design team (architect, structural engineer, mechanical engineer, civil engineer, geotechnical engineer, etc.) to coordinate the design and installation of the gas control and monitoring system. Geosyntec's previous experience working on large design teams, our early participation in project planning, and our building vapor protection system expertise led to a very smooth construction process that did not involve change orders from the contractor. Geosyntec worked with ODEQ to inform agency personnel on our proposed gas control technology and to facilitate the issuance of a permit to construct that did not impact the construction schedule. Geosyntec's involvement in the project resulted in obtaining the appropriate regulatory approvals with no impact to the schedule, thereby allowing Home Depot to open the store on-time.