As land becomes more valuable, reuse of abandoned or derelict land—including former landfills—is becoming more widespread. Landfills provide unique reclamation opportunities, as long as special monitoring and design considerations are established and followed, and as long as the public is convinced that reuse will not pose any threats to health and safety.
Adaptive reuse and redevelopment challenges include significant investments, technical complexities and regulatory requirements. Meeting these challenges requires both vision and commitment by corporate owners and public agencies. The first step in the process is creating a vision for the project and the site. The master planning process is the basis for establishing the site’s potential and developing the reuse vision. The planning process must be based on a strong understanding of the existing conditions and what can be reasonably accomplished. The public must be educated on the assessment processes and issues that will impact site reuse and design decisions.
Landfill closure and planned reuse considerations include settlement, the need for methane control and collection, site drainage, long-term maintenance requirements, wetland replication/remediation, slope stabilization, site monitoring, risk assessment for public use of the site and, last but not least, project costs and potential funding.
But what if we showed you how Jacobs and a public utility in the Commonwealth of Virginia came together to demonstrate how redeveloping a brownfield in an older city or suburban neighborhood can allow a community to remove blight and environmental contamination, create a catalyst for neighborhood revitalization, lessen development pressure at the urban edge and leverage existing infrastructure?
cubic yards of contaminated soil permanently removed from the site and planted native plant species with high habitat value that require no pesticides, herbicides and fertilizers – protecting surface and groundwater contamination.
gallon storage facility, topped with a public athletic field, stores wastewater during nutrient peaks to balance the amount of nitrogen that goes into biological treatment processes.
AlexRenew had a vision for repurposing an historic landfill site for expansion of their wastewater treatment facility and Jacobs helped make their vision a reality.
Changing treatment requirements, changing land use tactics
Alexandria Renew Enterprises (AlexRenew) operates one of the most advanced wastewater resource recovery facilities in the U.S., located on a fully developed and constrained 33-acre site (Main Plant site). Located in an urban setting, AlexRenew found itself in a unique situation needing approximately five acres to upgrade their facility to meet more stringent nutrient regulatory mandates but with limited room on their current property to build the needed facilities.
The public utility studied several expansion options and determined that five additional acres would provide an adequate amount of land for the necessary expansion to address the new regulations. The Main Plant site is part of a larger area that was historically used as a landfill by the City of Alexandria in the 1960s and 1970s. The historical landfill extends well beyond the current Main Plant site property boundary. Given the facility location between the Capital Beltway, historic cemetery and a City recreation and office building, there were limited opportunities for contiguous expansion.
The only available property with enough space to accommodate the expansion was located immediately to the west of the Main Plant site. AlexRenew acquired the property for the implementation of their 18-million-gallon Nutrient Management Facility (NMF). The NMF itself is a large, rectangular, flat top concrete structure approximately 240-by-430 feet.
The West Plant site is also part of the historic landfill area. To manage the long-term environmental liabilities associated with the landfilled material and waste decomposition gases, AlexRenew opted to enroll the property into Virginia’s Voluntary Remediation Program (VRP). The purpose of the VRP is to encourage environmental cleanups that otherwise might not take place. The program is a streamlined mechanism for site owners or operators to voluntarily address contamination, with concurrence from the Virginia Department of Environmental Quality (DEQ).
Mitigating risks and creating a lasting community asset
The approach for mitigating the potential human health risk associated with construction of the NMF at the West Plant site was accomplished through the implementation of a site-specific health and safety plan. Engineering and institutional controls were developed within the areas around the NMF since landfill waste would remain beneath the area after construction. These controls included clean cover, hardscape, fencing and clean utility corridors. Several land use controls were also imposed on the property, including:
- No groundwater or residential use.
- Requirements that the property will be covered by parking garages, buildings, asphalt, concrete or similar surfaces, or at least two feet of clean fill with the cover maintained.
- The installation and operation of gas collection systems using polyethylene vapor barriers, gas collection piping and blowers under buildings constructed on the property to prevent methane, other landfill gases or other volatile constituents from accumulating in buildings.
Many considerations to improve community quality of life were incorporated into the project, including a multi-purpose lit athletic field, built on top of the NMF. By building the athletic field, the NMF project restored previously inaccessible land, and added a recreational amenity to benefit the citizens of the City of Alexandria.
Jacobs led the master planning and design, provided engineering services during construction and helped incorporate sustainability throughout AlexRenew's entire nitrogen upgrade program. The project earned the first from the Institute for Sustainable Infrastructure in the Washington DC/Virginia metro region. The Envision rating system provides a holistic framework for evaluating and rating the environmental, community and economic benefits of large infrastructure projects that incorporate sustainability throughout the project life cycle.
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