Overview

This project for a provincial medium-security jail called for two wastewater treatment ponds, with 70,000 m2 (83,719 sy) of slopes and channels to install and protect. The project location had incredibly sandy and erodible soils due to the area being a sand deposit from Lake Agassiz that was created during the last ice age. With almost no salvageable topsoil, and due to the remote location of the site, hauling in and placing 4” of topsoil proved to be a significant expense at $6.00 per m2 (almost $9 per sy, USD). 

Issues

  • Sandy soil 

  • Highly erodible slopes 

  • Little-to-no reclaimable topsoil 

  • Other revegetation options cost prohibitive 

  • Significant rain event soon after installation

Problems

 Verdyol Biotic Earth was applied at a rate of 3900 kg/ha. Separate tacking agents were not required as the erosion control used on the site was a Bonded Fiber Matrix that includes tackifying agents. 

Solutions

 The decision was made to use Verdyol Biotic Earth as a topsoil alternative at a cost of only 54% what topsoil had been priced at. They chose S31 and S32 straw blankets as their erosion control on the project. 

Seed and fertilizer were applied along with the standard application rate of 3,900kg/ha (3,500 lbs/ac) of Verdyol Biotic Earth. With no cure time, the erosion control blankets could be installed right after the Verdyol Biotic Earth was applied. 

 

“Our expectations with the finished product have been far exceeded. Vegetation growth was rapid and consistent across the entire project site.” 

– Harry Schroeder P. Eng. LEED AP Project Manager 

Results

Vegetation was established quickly and evenly, and withstood a significant rain event soon after installation of 100 mm (3.9 inches) over a two-day period. There has been no erosion to speak of due to the full vegetation that has been maintained on the site.