Contaminated land remediation describes the process of isolating, containing or treating polluted soil and groundwater to make a site safe for redevelopment or long-term waste storage. Post-industrial brownfields, municipal landfill cells and industrial waste containment facilities all demand a reliable, impermeable barrier between contaminated material and the surrounding environment. Bentofix® geosynthetic clay liners (GCLs), Carbofol® HDPE geomembranes and Secutex® protection geotextiles provide proven barrier and containment systems that comply with the EC Landfill Directive, Environment Agency guidance and EN standards.
Naue geosynthetic systems are used wherever impermeable containment, groundwater protection and long-term durability are required on contaminated or waste-bearing sites.
Base and side-slope lining for municipal, hazardous and inert waste disposal cells.
Encapsulation of post-industrial contaminants enabling safe urban redevelopment.
Impermeable lining for leachate lagoons, sludge ponds and industrial storage basins.
Long-term barrier systems for mine tailings, heap leach pads and pit closures.
Final cover systems preventing rainwater ingress and landfill gas escape after cell closure.
On contaminated land projects, barriers must perform reliably from the first day of installation. Bentofix® GCLs are engineered to withstand installation stresses on uneven or soft subgrades without pre-treatment. Carbofol® HDPE geomembranes provide immediate sealing without a pre-hydration period. Secutex® protection geotextiles protect the membrane against puncture during backfilling.
Practical advantages:
An impermeable barrier is only one part of the containment system. Leachate generated by the waste mass must be collected and removed to prevent hydrostatic pressure from building up on the liner. Secudrain® drainage geocomposites fulfil this function directly above the barrier layer. Where fine particles from waste or cover soil risk clogging the drainage layer, Secutex® acts as a separation and filter layer.
The barrier seals the base. The drainage layer collects leachate. The filter separates waste from drainage. All three functions must be designed together.
The correct barrier product depends on a site-specific combination of contamination type, ground conditions, required hydraulic conductivity and regulatory specification. The decision table below provides a structured selection guide for the most common project scenarios.
| Criterion | Bentofix® NSP | Bentofix® X / X2 | Carbofol® HDPE | Composite system |
|---|---|---|---|---|
| Ground conditions | Soft/variable subgrade, municipal waste | Brownfield, post-industrial land | Good bearing subgrade required | Any conditions - combined layers |
| Contamination type | Inorganic leachate, municipal waste | Hydrocarbons, mercury, industrial chemicals | Any chemical - HDPE chemically inert | High-risk multi-contaminant sites |
| Hydraulic conductivity | k ≤ 5 x 10⁻¹¹ m/s (EN 14150) | k ≤ 1 x 10⁻¹⁴ m/s (PE coating, EN 14150) | k ≤ 1 x 10⁻¹⁵ m/s (HDPE) | k ≤ 1 x 10⁻¹⁵ m/s (composite) |
| Gas barrier function | Limited - additional membrane required | Yes - immediate from the day of installation | Yes - HDPE impermeable to gases | Yes - full composite barrier |
| Chemical resistance | Standard - suitable for inorganic leachate | High - PE coating resists hydrocarbons | Very high - HDPE inert to most chemicals | Very high - PE coating plus HDPE |
| Slope suitability | Yes - adequate overlap at seams (min. 300 mm) | Yes - overlap min. 300 mm + bentonite infill | Yes - MegaFriction variant for steep slopes | Yes - system design required for each site |
| Regulatory reference | EN 13493, EC Landfill Directive 1999/31/EC | EN 13493, EN 14150, ASTM D 5887 | GRI GM-13, ASTM D6693, EC Landfill Directive | EA Guidance Notes, EN 13493, BS 8006 |
| Recommended type | Bentofix® NSP 4000 / NSP 4900 | Bentofix® X2 NSP 4900 / X2 BFG 5300 | Carbofol® HDPE 406 (2.0 mm) | Bentofix® X2 + Carbofol® HDPE |
Regulatory compliance from day one
Bentofix® and Carbofol® products are tested and documented to EN 14150, EN ISO 10319 and GRI GM-13. Full compliance with the EC Landfill Directive (1999/31/EC) and Environment Agency guidance is achievable using Naue geosynthetic systems.
Reduced earthworks and lower project costs
Replacing a 1 m compacted clay mineral layer with a Bentofix® GCL eliminates significant excavation, material import, placement and compaction costs. Fewer lorry movements reduce haulage expenditure and programme duration.
Fast and straightforward installation
Bentofix® rolls are 4.85 m wide and 40 m long. They are unrolled directly onto the prepared, graded subgrade and overlapped by a minimum of 300 mm at all seams. Bentonite granules are placed in overlap zones to ensure sealing at joints. No specialist welding is required for GCL seam connections.
Self-sealing and long-term performance
The sodium bentonite core of Bentofix® swells on contact with water and self-seals around minor imperfections and penetrations. This self-healing characteristic ensures long-term hydraulic performance even after differential settlement. Carbofol® HDPE geomembranes provide a chemically inert barrier with a design life exceeding 100 years.
Contaminated land remediation is the process of isolating, containing or treating polluted soil and groundwater on former industrial, mining or waste disposal sites to prevent contaminant migration. A geosynthetic barrier is required whenever the site poses a risk of leachate, gas or contaminated groundwater reaching the surrounding environment. Bentofix® GCLs and Carbofol® HDPE geomembranes provide compliant containment solutions.
The choice depends on contamination type, required hydraulic conductivity and regulatory specification. Bentofix® NSP GCLs are suitable for standard municipal landfill applications. Bentofix® X GCLs are recommended for brownfield sites containing hydrocarbons, mercury or other industrial chemicals. Carbofol® HDPE geomembranes are specified where chemical inertness and minimum permeability are mandatory. Composite systems combine both products on high-risk sites.
The EC Landfill Directive (1999/31/EC) requires a composite liner with a mineral hydraulic conductivity of k ≤ 1 x 10⁻⁹ m/s. Bentofix® GCLs achieve k ≤ 5 x 10⁻¹¹ m/s (EN 14150). The PE-coated Bentofix® X2 achieves k ≤ 1 x 10⁻¹⁴ m/s. These values satisfy both the Directive and Environment Agency guidance for hazardous, non-hazardous and inert waste landfills.
Replacing a 1 m compacted clay mineral layer with a Bentofix® GCL eliminates substantial excavation, material import and compaction costs. Reduced lorry movements and cut haulage expenditure. Faster installation also reduces programme costs and site preliminaries.
Bentofix® rolls are unrolled directly onto the prepared, graded subgrade. Overlaps of a minimum 300 mm are required at all seams - bentonite granules are placed in the overlap zone to ensure sealing at joints. No specialist welding equipment is needed.
Key references include: EC Landfill Directive (1999/31/EC), Environment Agency Guidance (England and Wales), EPA Subtitle D / RCRA (USA), EN 13493 (geosynthetic barriers for liquid waste), EN 14150 (permeability testing), ASTM D 5887 (GCL hydraulic conductivity) and GRI GM-13 (HDPE geomembranes). Naue provides full test documentation and product certificates for all relevant standards.
Yes. Bentofix® GCLs and Carbofol® geomembranes have been installed on numerous landfill, brownfield and industrial remediation projects worldwide. UK references include Armstrong Waste Management (Scotland), Culmore Landfill (Northern Ireland), Bubbenhall Landfill (Warwickshire) and a major urban brownfield transformation in Glasgow. Find further case studies on this page.
Naue provides site-specific chemical compatibility assessments for Bentofix® X and X2 GCLs. The PE coating on Bentofix® X is evaluated against the site leachate chemistry using ASTM D 5887 and EN 14150 test methods. For the Glasgow urban brownfield project, Naue confirmed long-term compatibility with hydrocarbons and mercury and provided a full product warranty based on site-specific chemical analysis. Contact Naue’s Engineering and Design Department (EDD) for a project-specific compatibility assessment.
Secudrain® drainage geocomposite is installed directly above the primary sealing barrier (Bentofix® GCL or Carbofol® geomembrane). It collects and drains leachate under gravity, reducing the hydrostatic head acting on the liner system. Lower leachate pressure reduces the hydraulic gradient driving contaminant migration, extending barrier integrity. The integrated Secutex® filter nonwoven prevents fine particles from contaminating the drainage core and clogging the geocomposite over time.
The design of geosynthetic barrier systems for contaminated land and landfill construction is based on recognised standards and site-specific data including waste classification, leachate chemistry, slope geometry and seismic conditions. Naue technical engineers provide design support and product recommendations tailored to your site requirements and regulatory framework.
Naue Carbofol® is a HDPE liner for landfill sealing, mining containment, and groundwater protection.
Naue Bentofix® is a geosynthetic clay liner (GCL) for waterproofing in landfill engineering, groundwater protection and hydraulic applications.
Naue Secutex® is a mechanically bonded nonwoven geotextile for separation, filtration and protection in roads, railways and hydraulic engineering projects.
Naue Secudrain® is a geosynthetic drainage geocomposite for landfill, groundwater protection and building structures.
Naue Bentofix® X geosynthetic clay liner is a multicomponent PE-coated GCL for landfill, waterproofing and slope sealing.
