Part of WaterSolve’s environmental services includes what the geotechnical industry refers to as Sludge Lagoon Closure.

There are two main methods of sludge lagoon closure:

1. A lagoon may be dredged and removed/dewatered utilizing geotextile tubes prior to closure
2. Or the sludge can be left in place and encapsulated.

Leaving the sludge in place often requires the sludge to be reinforcement to support the final cap.  Safe capping of high-water content waste disposal lagoons or ponds is required in order to prevent groundwater contamination.

An in-situ cap above the sludge consists of the following:

    • A Panelized (Sewn) High Strength Woven Geotextile is installed with its strength determined by vane shear analysis of the sludge.
    • A drainage medium consisting of either a sand layer or geo-net system is installed.
    • A geo-membrane or clay layer (to include a GCL) is installed.
    • The lagoon is then brought to design grade while maintaining minimum cover.

Additionally, we perform Living Shoreline development for marsh and dune restoration. We have worked for state and local agencies to help Mother Nature in the process of erosion resistance and habitat establishment.

In accordance with environmental regulations, the retirement of large industrial waste storage facilities has become a critical cost issue for industries and a challenge to the geotechnical community. Lagoon Closure (capping), if practical, typically offers the least expensive solution to the remediation of contaminated sludge facilities. This approach allows for sludge to remain in place and isolated and prevents the accidental falling of humans and animals and ingestion of contaminated sludge. If required, infiltration of rain and surface water can be blocked. Caps can be impervious if infiltration of water and generation of leachate is to be limited or pervious when leachate generation is not a concern such as in natural attenuation sites and/or with certain type of contaminants (e.g., PCBs and asbestos are quite insoluble and do not transport with water).

Lagoon Capping


WaterSolve and our strategic partners work with the client’s engineer and contractor to address such technical issues as:

Final Location Use

Final use for the capped lagoon (parking lot, recreational facility, etc.)

Treatment of Surface Water

Treatment of surface water and water drained during the consolidation of sludge

Supply & Installation

Supply and installation services of high strength woven geotextile, drainage medium, backfill and geo-membrane by our team of strategic partners.


Analysis of vane shear test results to develop the most efficient high strength woven geotextile for this application

Reinforcement Panel Plan

Development of a reinforcement panel plan

Lagoon Capping & Closure for Environmental Solutions


The process of capping can present varied geo-technical challenges which our experienced team is positioned to successfully manage to include:


  • Handling and disposal
  • Dewatering
  • Stabilization
  • Hydraulic performance
  • Settlement
  • Stability
  • In-situ testing
  • Construction


These materials are typically contained in surface collection areas or impoundments such as lagoons, ponds or old quarries. Some of the remediation alternatives include:

  • Beneficial Reuse
  • In-Situ Chemical Stabilization
  • Ex-Situ Treatment
  • Landfill Disposal
  • Capping


Many storage and waste facilities were constructed prior to the establishment of modern environmental regulations and contain a variety of contaminated high-water content materials.


  • PCB (polychlorinated biphenyls) containing wastewater treatment sludges
  • Contaminated Harbor Dredgings
  • Waste Pickle Liquor Sludges
  • Asbestos – containing sediments
  • Contaminated River Bottom Sediments