Technical Challenge
Burrowing animals present an ongoing management challenge both in aquatic and terrestrial settings. Degradation to dikes, berms, and shorelines of valuable water resources from animals such as muskrats, nutria, and beaver can lead to leaks that may start small but worsen with time. Sourcing appropriate backfill material – manmade or natural – is often problematic and the physical properties of conventional fill materials (e.g. concrete, stone, native clay, raw bentonite) have their shortcomings.
AquaBlok® Solution
AquaBlok offers a simple and cost-efficient alternative that both repairs existing damage and can discourage burrowing animals from re-excavating into the original cavity. The combination of the structural stability of the stone core in each particle coupled with the swell and low permeability of the bentonite “wrapping” when hydrated produces a durable and reliable seal. Plus, the rounded contours of the dry material make AquaBlok highly “flowable,” allowing for it to readily fill void spaces.
Unlike concrete that shrinks, cracks, and degrades, especially when buried and exposed to water, AquaBlok expands, self-heals, and remains somewhat plastic when wet. The consistency and structural competency of the stone-bentonite composite also outperforms native clays and even raw bentonite for these types of spot-treatment repairs.
Depending on the extent of the damage (volume, depth, and complexity of the tunneling) sealing can be as simple as placement of a small amount of product into the entrance hole of an animal burrow. Larger and more complex damage caused by tunneling and multiple entry excavations typically require a broader application over a larger area. Each “run” can be addressed individually or, when adjacent to water, a vertical core trench can be cut at the upper limit of the infestation and backfilled with AquaBlok, creating a structurally stable wall of sealant material.
Equipment Needed
Smaller and simpler backfills can often be accomplished using hand tools (e.g. shovels, spades, etc.). More extensive damage may require a hand auger, trencher, or even mini-excavator.
Material Needed
Product requirements for this application vary. For single cavity applications, one to several 50-lb. bags of AquaBlok may be sufficient. If a larger excavation is needed to ensure complete reinforcement, handling AquaBlok in bulk bags by the cubic yard may be more cost-efficient (particularly where equipment is already available on-site). AquaBlok has a dry bulk density of ~90 lbs/cubic foot. This means that a 50-lb bag is roughly enough to fill a 5-gallon bucket and a cubic yard of dry material weighs approximately 2,400-lbs.
Tips & Observations
When possible, removal of the animal(s) responsible for the burrowing (through trapping, etc.) is always the best first step in reducing future damage. AquaBlok is not a preventative tool in this case and it will not eliminate the source of the problem.
Care should always be taken to ensure that the animal is not present (i.e. cornered inside the burrow) during repair.
Product can be “plunged” horizontally into a cavity by hand or using a long-handled tool.
Access to larger cavities/dens can be gained by drilling vertically with an auger or post-hole digger from above. Material can then be poured into the newly accessible cavities and voids.
Blending material with native soil is not recommended for this application.
Mechanical compaction will not hurt product performance, but is not typically necessary provided voids are filled completely.
Do not think of the material as expanding spray foam. The goal is to fill all accessible void space, creating a “plug” of product that swells to completely fill the entrance to a cavity.
While the material does swell in all directions, the percent swell reduces as product thickness increases (due to self-compaction).
Water can be poured or sprayed over newly placed material to jump-start hydration, but water need not be added to make the product effective. Even if left in a dry state, precipitation, surface run-off, and moisture from surrounding soils will eventually hydrate the individual particles into a single body of material, except in avid environments.