Anti-Seep Collars/Trench Dams


Addressing Problems Associated with Seepage Along a Pipe

The traditional construction method of placing a pipe on an aggregate bed essentially creates a conduit or high permeability zone for water to follow along the length of the pipe. Seepage creates erosion and can gradually (and sometimes rapidly) undermine the backfill
surrounding a pipe. Depending on where the failure occurs (i.e. under a roadway or in an
overflow pipe leading from a basin), a significant breach or safety issue can occur. Typical
applications include:

  • Water or sewer piping
  • Water control structures or overflow piping for basins/ponds
  • Underground utility corridors
  • Minimizing Inflow & Infiltration (I&I) from inlets or manholes - aging infrastructure
  • Oil & gas pipeline construction (including stream crossings or wetland protection)

Traditional Approach

Historically, anti-seep collars, also known as trench dams, have been constructed from a range of
materials, including rubber, concrete, corrugated metal, foam, et al. With these approaches,
installation is often time consuming and can be technically problematic. Another alternative
uses 50lb paper bags of traditional bentonite chips (stacked in the trench) to achieve a dam
or collar around a pipe. However, for a number of key reasons, this approach actually is far
more expensive and technical and much less effective than some of the other more
traditional alternatives.


The AquaBlok Solution

Although AquaBlok was originally developed as a material to limit the spread of
contamination, it has been widely applied to a range of water control applications. Its
physical composition (high aggregate solids content and low permeability) makes it
particularly well-suited to serve as a collar or “plug” around a pipe. The stone-core provides structure and support for the exterior of a pipe, just as any bedding aggregate would. The bentonite provides an extremely erosion-resistant and permanent seal. Since it is placed in dry form, AquaBlok will “flow” around and under a pipe, filling voids and inconsistencies in the surrounding substrate. Once hydrated, the material conforms tightly to complex shapes, like trench side walls, bedding material, and the curvature of a pipe.

How Much Material Do You Need?

Pipe size and surrounding soil properties determine how much material you will need. To
assist, we have provided example drawings and specifications, as well as a method to
determine material quantity for a single trench dam.

Download PDF Sample Drawing

Download PDF Sample Specification Language

Download PDF AquaBlok Packaging Options – Contact any of our distributors to receive help estimating quantity need and to receive a custom quote.

Calculate Material

Tips & Observations

Things to Consider

  • Utility Installation vs. Repairs
  • Commercial vs. Industrial Sites
  • Basin Penetrations
  • Wetland Environments

Other Uses for AquaBlok

  • Our material is also suitable as a vapor barrier around a conduit. Provided it will remain hydrated, AquaBlok will prevent the undesirable migration of gases, like methane. 

Technical Advantages

  • When native backfill is inconsistent or tight clays clump and are difficult to handle and re-compact, AquaBlok is particularly advantageous.

From the Field

Photo Gallery

Download Literature on AquaBlok