GZA has provided multidisciplinary engineering and environmental services for the Allied Waste Niagara Falls Landfill since 2000. Our work has supported the landfill’s development from permitting and cell construction through final cover installation and long-term operational planning.
Challenge
Expanding an active landfill required GZA to address complex subsurface conditions while maintaining ongoing waste operations. The 84-acre expansion area contained substantial quantities of industrial fill, including waste lime and contaminated soil associated with a former hazardous waste treatment facility. The design also needed to integrate new landfill cells with existing cells, previously capped slopes, stormwater infrastructure, and leachate collection systems.
Later construction phases introduced additional challenges. A 12-acre cell liner was built over historic industrial fill and required connection to previously constructed, adjacent landfill cells, including a portion of a previous capped slope. During construction of a separate 12.3-acre final cover, field surveys revealed that waste and intermediate cover elevations did not match the design grades, requiring a rapid engineering response to keep construction moving.
Solution
GZA prepared the State Environmental Quality Act (SEQRA) permit application for the landfill expansion and designed double-composite liner and leachate collection systems consistent with New York State Department of Environmental Conservation (NYSDEC) requirements. The design strategically managed millions of cubic yards of waste lime through excavation, controlled reuse, and construction over material left in place. GZA also investigated contaminated areas, directed remedial excavation and off-site disposal, and designed stormwater improvements and double-contained leachate clean-out systems.
For Sanitary Landfill VII Subarea F cell liner, GZA developed permit and bid documents, designed liner configurations adapted to varying site conditions, and provided construction quality assurance, soils testing, and geosynthetics testing.
GZA also designed the 2023 final cover for Sanitary Landfill VIII, including drainage, gas venting, and connections to the existing gas collection system. When unexpected grading conditions emerged, GZA expeditiously revised the three-dimensional surface model to balance excavation and fill quantities while maintaining required slopes, avoiding construction delays.
GZA’s annual aerial budget modeling (ABM) and five-year planning also help the client track remaining disposal capacity, estimate landfill lifespan, forecast material needs, and schedule future cell and cap construction.
Benefit
For over two decades, GZA’s integrated services have helped the client expand disposal capacity, remediate historical industrial impacts, maintain regulatory compliance, coordinate construction with active landfill operations, and conduct long-term planning.
