Excel recommended a fully HDPE leachate collection approach better suited for high‑groundwater conditions. The final system incorporated HDPE structures designed to resist uplift forces and maintain stability under groundwater‑at‑grade conditions, providing a reliable, long‑term solution for the landfill expansion.

	Engineer Geosyntec is an employee-owned consulting and engineering firm focused on environmental, natural resources, and civil infrastructure projects. Since its founding in 1983, the firm has delivered technical services to public- and private-sector clients, with core expertise in contaminated site remediation, water resource management, and geotechnical engineering.
	Contractor COMANCO is an environmental and civil construction contractor specializing in geosynthetics installation and containment systems. Founded in 1989 and headquartered in Plant City, Florida, the company supports sectors such as mining, solid waste, and power generation, with a strong emphasis on safety, quality, and environmental stewardship.
	Pump Station End User Located in Vero Beach, Florida, the Indian River County Landfill is a solid waste disposal facility that handles multiple waste streams and protects surrounding soil and groundwater through containment systems, leachate collection infrastructure, and continuous monitoring to maintain regulatory compliance and safe long-term operation.

As part of their landfill expansion project, the Indian River County Landfill needed to extend its leachate collection framework to accommodate increased waste capacity. The system was originally specified with a concrete wet well lined with HDPE, but site conditions introduced additional design considerations.

Due to the project's location in Florida, groundwater levels were assumed to be at grade, increasing the risk of groundwater infiltration and buoyancy. The environmental risk posed by the potential of groundwater and leachate mixing was a large threat for regulatory compliance that needed to be addressed. Uplift forces also presented a concern, as they could compromise structural stability and impact long‑term system performance. To address these risks, the design was required to incorporate buoyancy countermeasures capable of maintaining a 1.25 safety factor under worst-case groundwater conditions.

The Solution:

To address the aforementioned challenges, Excel opted to take an alternative approach centered on fully fabricated HDPE structures. These systems were better suited for the site's conditions, simplified installation, and offered improved resistance to corrosion and leachate.

The final system incorporated two primary components: a 4‑foot‑diameter by 12‑foot‑deep Weholite HDPE wet well to support active pumping operations, and a 5‑foot‑diameter by 12‑foot‑deep LCS HDPE manhole designed to receive passive flow. Both structures were engineered with reinforced bases and stabilization features to address buoyant forces acting on the system.

These buoyancy countermeasures were designed to meet the 1.25 safety factor against flotation under high-water conditions. A custom TCU800 control panel was also incorporated to support system operation. Together, all of these design elements delivered a leachate collection system that supported the landfill expansion while increasing durability, performance, and cost efficiency.