TRMs with Recycled Fibers Help Contain Fly Ash

Vegetated channels have years of proven success. However, when vegetated channels are part of the plan to protect fly ash ponds, they must be constructed in a way that ensures long-term protection of the environment.
Turf Reinforcement Mats (TRMs) have a wide range of benefits that make them a logical choice for protecting fly ash ponds. The vegetated channel reinforced by a TRM at the power plant featured herein was designed to successfully transmit runoff from the site, while preventing erosion that could potentially expose the fly ash. Based on the design parameters, the expectant shear stress exceeded the permissible shear stress rating of vegetation alone. Thus, a TRM was needed to provide higher performance capabilities via a reinforced vegetated channel.
Vegetated channels with TRMs have additional benefits as compared to traditional hard armor solutions such as rip rap. The channels provide aesthetics in the landscape, are softer and safer than rock, and provide easier accessibility. Installed costs of TRM reinforced vegetated channels are considerably less than rip rock depending on the exact project location. Carbon sequestration along with filtration of contaminates such as nutrients and heavy metals are provided by the vegetated TRM channels. Also, water infiltration is increased with vegetated TRM channels and discharges are cooler than channels with hard armor. Properly installed vegetated TRM channels additionally serve as pollinator corridors and provide animal habitat.
There are many TRMs to choose from and while all types reinforce vegetation, there are products that have features that make them a better choice. One such feature is TRMs that have a specific gravity greater than one that do not float during hydraulic events. Additionally, there are lighter colored TRMs that may positively impact vegetation growth because they do not cause high seed bed temperatures that can lead to burn out.
.