Overview

A side slope from a roadway ended at the fence line of a private property on this project; so long-term vegetation to prevent possible erosion was a necessity. Climatic conditions in the area are exceedingly hot and dry, with summer temperatures reaching triple digits, and average rainfall slight. In this region adequate densities of vegetation are regularly difficult to achieve. 

Issues

  • Sandy soil 
  • Highly erodible slopes 
  • Little-to-no reclaimable topsoil 
  • Other revegetation options cost-prohibitive 
  • Significant rain event soon after installation 

Problems

 This project for a provincial medium-security jail called for two waste water 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). 

Application
Application

Solutions

Due to low fertility and quality of the available topsoil, Innovative Soil Solutions recommended Biotic Earth, a Biotic Soil Amendment, to achieve vegetation long term on the site at acceptable densities and without the need for constant supplemental watering and fertilizer applications. Soiltech, Inc. applied Biotic Earth, Earthbound 200 tackifier, and seed hydraulically in late summer of 2016. Straw erosion control blankets were applied in the following days to provide temporary erosion control on the site.

Results

 

 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 

Details

  • Biotic Earth: applied at 3,500 lbs./AC
  • Earthbound 2000 tackifier: applied at 35 lbs./ AC
  • TXDOT Seed Mix: District 21, Permanent, Urban Clay Soils Seed Mix (PLS) Green Sprangletop - 0.3lbs /AC Sideoats Grama (Haskell) - 3.6lbs/AC Buffalograss (Texoka) - 1.6lbs/AC Bermudagrass - 1.8lbs/AC
After