7 Mistakes You are Making Landfill Covers (and How to Avoid PFAS Disaster)

 

Environmental regulations regarding Per- and Polyfluoroalkyl Substances (PFAS) are entering a phase of aggressive enforcement. The Environmental Protection Agency (EPA) has designated PFOA and PFOS as CERCLA hazardous substances. This shift fundamentally alters the liability landscape for landfill owners and operators. Failure to contain these “forever chemicals” is no longer a technical oversight; it is a significant financial and legal risk. 

Many operators continue to utilize outdated containment strategies designed for a pre-PFAS era. These legacy methods prioritize simple hydraulic conductivity over molecular diffusion control. This approach creates “Profit Killers” in the form of regulatory fines, litigation, and expensive remediation requirements. Achieving Total Asset Integrity requires a transition from commodity plastics to highly engineered barrier systems. 

Avoid these seven critical mistakes to ensure long-term compliance and environmental safety. 

1. Relying on Standard HDPE for PFAS Containment 

Standard High-Density Polyethylene (HDPE) is a reliable hydraulic barrier for many traditional waste streams. However, HDPE is not an absolute barrier against the diffusion of PFAS. Research indicates that shorter-chain PFAS compounds can migrate through standard polyethylene membranes over extended periods. 

• Stop treating hydraulic conductivity as the only metric of success. 

• Acknowledge that diffusion is the primary transport mechanism for PFAS through geomembranes. 

• Transition to co-extruded EVOH (Ethylene Vinyl Alcohol) barriers for critical containment zones. 

Absolute Barrier® utilizes a seven-layer co-extruded design with an EVOH core. This specific engineering reduces VOC and PFAS diffusion by orders of magnitude compared to standard HDPE. Implementing Absolute Barrier protects the surrounding groundwater and reduces long-term CERCLA liability. 

2. Neglecting Seam Integrity and Detail Sealing 

A high-performance membrane is only as effective as its weakest connection. Traditional welding methods are necessary but often insufficient for blocking gas-phase or dissolved PFAS migration at the molecular level. Standard seaming focuses on water tightness but may allow for microscopic vapor transmission. 

• Eliminate the use of general-purpose construction tapes for critical seams. 

• Ensure all penetrations and edge details use gas-tight sealing technology. 

• Inspect every linear foot of seaming with rigorous Quality Assurance (QA) protocols. 

Without a gas-tight seal at every joint, the primary barrier is compromised. 

3. Using Inadequate Ballasting Systems 

Temporary and intermediate covers are frequently lost to wind uplift. Using traditional tires or scattered sandbags creates uneven pressure and provides inconsistent protection. Wind-induced vibration can cause micro-tears in the geomembrane, leading to increased infiltration and leachate production. 

• Discard the use of tires which trap water and attract pests. 

• Deploy continuous ballasting solutions to secure long seams and perimeter edges. 

• Ensure the ballast weight is sufficient for regional wind load requirements. 

Sandtubes provide a continuous weighted barrier that keeps the geomembrane in direct contact with the waste mass. This prevents the “parachute effect” during high-wind events and ensures the cover remains functional throughout its service life. 

4. Disregarding Material Lifespan for Interim Covers 

Operators often choose the cheapest possible film for interim covers, assuming a short service life. However, interim covers frequently remain in place longer than planned due to operational delays or regulatory hurdles. Commodity films degrade quickly under UV exposure, leading to brittleness and failure. 

• Select materials with high UV stabilization and antioxidant packages. 

• Verify the chemical resistance of the film against landfill gases and leachate. 

• Invest in reinforced materials to prevent tear propagation. 

Dura-Skrim® reinforced films offer superior puncture and tear resistance. These engineered films provide the durability required for long-term exposure, preventing the need for frequent and costly cover replacements. 

5. Overlooking VOC and Gas Diffusion Control 

PFAS is often found in conjunction with other volatile organic compounds (VOCs). Standard geomembranes act like sponges for certain hydrocarbons, allowing them to pass through the material via a process called permeation. This results in odors and potential hazardous gas releases even if the liner has no physical holes. 

• Evaluate the barrier performance against methane, radon, and VOCs. 

• Recognize that a thick HDPE liner does not necessarily equate to a better gas barrier. 

• Implement multi-layer technology to block diverse chemical species. 

The EVOH core in Absolute Barrier X-Series is designed specifically to block these gases. This technology provides a comprehensive solution for both liquid containment and gas migration control, ensuring the landfill remains a “good neighbor” to surrounding communities. 

6. Failing to Address Perimeter and Edge Containment 

The perimeter of a landfill cell is a common point of failure. Improper termination at the anchor trench or weak transitions to existing cells allow PFAS-laden leachate to bypass the primary containment system. 

• Construct robust anchor trenches that follow manufacturer specifications. 

• Use specialized tapes and adhesives to bond new liners to existing structures. 

• Prevent surface water from undermining the cover at the edges. 

Total Asset Integrity requires a holistic view of the containment site. Every edge must be treated with the same technical rigor as the center of the cell.  

7. Choosing Commodity Plastic Over Engineered Solutions 

The most significant mistake is treating geomembranes as a commodity. Choosing a liner based solely on price per square foot ignores the total cost of ownership. The “savings” from a cheaper liner are erased by the first regulatory fine or leachate treatment surcharge. 

• Consult with engineers who specialize in PFAS and VOC containment. 

• Demand technical data sheets that include diffusion rates, not just physical strength. 

• Prioritize Total Asset Integrity over short-term procurement savings. 

Viaflex provides Design-Build Solutions that leverage decades of expertise in complex containment. Using engineered films specifically designed for the PFAS era is the only way to safeguard the future of a waste management facility. 

Summary of Directives for Landfill Operators 

Compliance in 2026 requires a proactive stance on material selection and installation quality. 

• Replace standard HDPE with EVOH-based Absolute Barrier for PFAS cells. 

• Protect covers from wind damage using Sandtubes. 

• Select reinforced Dura-Skrim materials for all temporary and interim applications. 

• Focus on the molecular diffusion of contaminants, not just hydraulic flow. 

Contact Viaflex to discuss specific technical requirements for your next containment project. Avoid the Profit Killers of the PFAS era by investing in engineered protection today.