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. Long-term seepage creates erosion and can gradually (and sometimes rapidly) undermine the backfill surrounding a pipe, leading to structure failure. Depending on where the failure occurs (e.g. 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 and trench breakers, 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 or sand bags (stacked in the trench) to achieve a dam or collar around a pipe. However, for a number of key reasons, these approaches actually can be far more expensive, less safe, and much less effective than an AquaBlok approach.
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. The hydrated dam will be much less susceptible freeze/thaw, desiccation/rehydration cycles - will not crack over time from the effects of highway vibration or seismic loads.
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. Trench depth and the size of the pipe will typically determine the minimum thickness of the AquaBlok in the trench. However, Constructability considerations may also impact thickness specification language for more information.
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 minimize 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
Sherbrooke Street Utility Repair (New Westminster, BC)
Angler Mountain Development (Silverthorne, CO)
Simonson Place Storm Outfall (Camano, WA)
Worcester Regional Airport Storm Drains (Worcester, MA)