COMANCO Continues Closure Work at New River Landfill with Phase II EGC System
Rethinking Closure Systems in Modern Landfills
Landfill closure is not simply about covering waste; it is about delivering a system engineered to perform for decades under real-world environmental conditions. As landfills continue to serve growing communities, closure solutions must balance regulatory compliance, environmental protection, and long-term reliability.
Traditional closure methods often rely on soil cover and vegetation. While familiar, these systems can introduce long-term maintenance challenges, erosion potential, and performance variability driven by settlement and weather exposure.
As regulatory expectations increase and site conditions become more complex, owners are looking for alternatives that reduce risk and improve long-term performance. One such approach is the exposed geomembrane cap (EGC), a system that eliminates soil cover while maintaining stringent environmental protection standards. When executed correctly, EGC systems offer enhanced durability, reduced long-term maintenance, and predictable performance.
COMANCO has recently mobilized to begin Phase II of the New River Landfill EGC Closure Project in Raiford, Florida. This phase builds upon carefully executed prior work and advances a closure system specifically designed to support the landfill’s long-term role in serving the surrounding community.
Managing Leachate and Gas Without Traditional Cover Systems
Closure systems must successfully manage two critical components: leachate control and gas management. When these systems are not fully integrated, risks increase—leachate migration can threaten groundwater, while unmanaged gas can lead to pressure buildup and safety concerns.
In traditional systems, soil cover adds weight and protection. It also introduces variables such as settlement, erosion, and vegetation maintenance. Over time, these factors can compromise system performance and increase long-term costs.
This project takes a different approach. The exposed geomembrane cap eliminates soil and sod entirely, placing full reliance on engineered components. Without a soil buffer, every element of the liner system—trenching, seams, and piping—must perform exactly as designed.
Phase II follows Phase I, which COMANCO completed in 2020. Seamlessly tying new construction into an existing exposed system requires careful coordination, precise execution, and a comprehensive understanding of long-term performance considerations. This continuity is essential to ensuring the closure functions as a single, unified system rather than separate phases.
Precision in Liner, Trenching, and Piping Installation
The scope of work for this phase includes installing approximately 514,573 SF of 60 mil textured HDPE liner, along with 6,440 LF of piping dedicated to gas and leachate control. Solmax supplied the geomembrane materials, and ISCO supplied the piping systems.
Execution begins with trenching that supports the ballast system—one of the project’s most critical elements. Unlike conventional anchor trenches, this innovative design incorporates an 18‑inch offset fusion weld within the ballast trench system. This unique configuration securely anchors the exposed liner while eliminating the need for soil cover and sod. The design demands exacting craftsmanship and a high level of installation expertise.
With no soil cover to conceal imperfections, installation quality becomes paramount. Seam integrity, trench construction, and material handling must meet strict standards. Thorough testing and documentation are essential, as each weld is exposed and relied upon for long-term performance under environmental stress.
Piping installation is fully integrated into the system to manage both gas and leachate. Proper alignment, slope, and connection details are essential. Even minor deviations can impact system efficiency and performance after closure.
This approach reflects an evolution in exposed geomembrane cap design and construction—one that prioritizes engineered precision, simplifies long-term maintenance, and demands exceptional execution in the field.
Building on Proven Experience
This project represents a continuation of COMANCO’s work at the New River Landfill, making it a repeat partnership. That continuity provides a clear advantage. Familiarity with site conditions, prior construction methods, and system behavior allows the team to execute with efficiency and confidence.
Under the leadership of Superintendent Jorge Gomez, the crew has mobilized and begun coordinating field activities to align with the existing closure system. Early-stage coordination focuses on layout verification, material staging, and sequencing to support efficient installation. The crew is currently installing a toe drain system consisting of a 6-inch perforated HDPE pipe wrapped in gravel and geotextile to collect and distribute leachate seepage at the bottom of the slope. This system must be installed before the EGC liner is installed to ensure proper drainage and system performance.
The highly specialized nature of this closure system is reflected in the procurement process. The project’s unique design, combined with the technical demands of exposed geomembrane installation and ballast trench welding, requires experience well beyond standard liner work.
Safety, quality control, and regulatory compliance remain at the forefront. Crews adhere to strict welding, testing, and documentation procedures, with daily coordination ensuring trenching, liner placement, and piping installation progress seamlessly.
Getting Closure Right the First Time
Landfill closure systems are long-term community investments. Decisions made during construction directly impact performance, maintenance requirements, and environmental protection for years to come.
Phase II of the New River Landfill EGC Closure demonstrates how alternative closure methods can address common challenges while improving reliability. By eliminating soil cover and focusing on engineered solutions such as exposed geomembrane caps, owners can reduce long-term risks and maintenance requirements.
COMANCO’s involvement across both phases of the New River Landfill EGC Closure Project highlights the importance of continuity, planning, and execution. When liner systems, trenching, and piping are constructed correctly from the outset, the result is a closure system built to perform for the long term.
Getting it right the first time is not optional—it is essential for successful, sustainable landfill closure.
SAFETY ★ QUALITY ★ SERVICE
COMANCO is an environmental, commercial, and civil construction company specializing in constructing containment facilities.
Landfill closure requires careful coordination of liner systems, trenching, and piping to ensure long-term environmental protection. Projects like the New River Landfill demonstrate the importance of precision and experience when working with exposed geomembrane cap (EGC) systems. COMANCO brings proven field expertise to every phase of closure construction. Contact COMANCO to learn how we can support your next project.
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