Geosynthetic Liner

May 6, 2026

A recent examination by SCS Engineers Project Directors Evan Guignon, PE, and Michael Bradford, PE, into geosynthetic liner damage and repairs examined the permeability of geosynthetic liners used in waste containment systems. Their blog focuses on the significance of lined containment, the perception versus reality of liner permeability, liner installations, and liner repairs.

Importance of Lined Containment

Lined containment is crucial for managing solids, liquids, and gases in waste containment systems. Over the past 50 years, regulations such as CCR Title 27, Title 40 CFR, and RCRA (Subtitle D) have emphasized the need for effective containment.

Liner Permeability: Perception vs. Reality

The common perception is that geomembrane barriers are impermeable and that lined ponds are watertight. However, even a “perfect” liner will leak through diffusion. The leakage rate is influenced by the head over the liner, ranging from 1 to 8 gallons per acre per day for a standing head of 1 to 10 feet deep.

Minimizing Leaks: Liner Installations

Successful liner installations involve multiple stakeholders, including manufacturers, installers, design engineers, Construction Quality Assurance (CQA) engineers, and laboratories. Common defects and damages during installation include manufacturing defects (e.g., needle holes), installation errors, equipment damage, and issues with waste/material placement. CQA (Construction Quality Assurance) engineers play a vital role in minimizing these defects and ensuring the liner’s integrity.

Detecting and Managing Leaks

Single-lined facilities use groundwater or soil gas vapor monitoring wells to detect leaks. Dual-contained facilities use leak detection systems called pan lysimeters. The EPA Action Leakage Rate (ALR) recommends 1,000 gallons per acre per day for ponds and 100 gallons per acre per day for landfills. States can set their own ALR values based on the type and function of containment. If leaks exceed the ALR, inspections and repairs are performed to address liner containment.

Liner Repairs

When damage occurs to ponds or cells, repairs are necessary. Damage can be internal (e.g., wrinkles, creases) or external (e.g., rocks, operations, environmental factors). Long-term UV exposure, catastrophic events (e.g., fire or wildlife), and slope stability failures can also cause damage. Repair solutions for ponds and impoundments involve draining, cleaning, and replacing or repairing the liner. The process for cells includes exposing them, cleaning them, and repairing or replacing the liner.

Geosynthetic Liner Conclusion

The design, material manufacturing, installation, CQA services, lab testing, and leak/damage monitoring all contribute to the overall effectiveness of the containment system. CQA, with continuous monitoring and timely repairs, is essential to maintaining the integrity of these systems.

About the Authors: 

Evan Guignon, PE has experience with semiannual reporting, exceedance tracking, and regulatory compliance related to environmental projects. He has training in AutoCAD Civil 3D Advanced Landfill Grading Applications and Plant 3D Modeling. Evan’s background includes stream restoration design planning and research involving cement sample preparation and testing according to ASTM standards. Mr. Guignon holds multiple state Professional Engineer licenses.

Michael Bradford, PE brings over 20 years of experience in civil engineering and project management, specializing in solid waste landfill and public works projects. His expertise includes landfill site planning, excavation and grading design, stormwater management, geosynthetic liner design, landfill gas collection and control systems, and leachate recovery system design. Mr. Bradford has managed large-scale landfill expansions and closure projects, including permitting and construction quality assurance, and holds multiple state Professional Engineer licenses as well as CQA/CQC certification for geosynthetic materials inspection. His work includes managing permit modifications and landfill expansions that extended facility life by decades, demonstrating his capability in regulatory compliance and technical leadership.

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