Soil thickness (ST) was defined as the depth from the top soil profile to the weathered bedrock.

Topsoil is the upper, outermost layer of soil, usually the top 5–10 inches (13–25 cm). It has the highest concentration of organic matter and microorganisms and is where most of the Earth’s biological soil activity occurs. Topsoil is composed of mineral particles, organic matter, water, and air.

The A-horizon is commonly referred to as the topsoil, and typically ranges from 8-20 cm in thickness. It is a mineral horizon that formed at the surface or below an O-horizon, and is characterized by an accumulation of humified organic matter intimately mixed with the mineral fraction.

Soil improvement in its broadest sense is the alteration of any property of a soil to improve its engineering performance such as strength, reduced compressibility, reduced permeability, or improved ground water condition.

Professor of Biological Sciences at Université de Montréal “Our goal is to develop an eco-friendly technology to clean up polluted soils using plants and microorganisms, like bacteria and mushrooms. These organisms use oil as a source of food. They feed on it and break it down, gradually decontaminating the soil.

Remediation Process means the method used to address the teaching performance of a teacher who has been identified as partially effective or ineffective and whose performance has not sufficiently improved. Such method may include a Directed Improvement Plan (discussed below).

20 to 30 years

Phytoremediation consists of decreasing pollutant concentrations in contaminated soils, by growing plants able to degrade to an acceptable level or render harmless the contaminants in the soil. In total, the process will take approximately one year, depending upon the severity of the contamination and the location.