In 1992, in response to increasing demand for a solution for the treatment and disposal of hydrocarbon impacted soil, Envirosoil received approval to develop a bioremediation facility. The facility, which was designed by Jacques Whitford Environmental Limited (JWEL), was constructed and started receiving impacted soil in the fall of 1992. JWEL also provided the environmental monitoring for the facility.
The intent of the bioremediation process was to promote the degradation of the petroleum hydrocarbon contaminate in soils, by way of consumption by microbial life, which used petroleum hydrocarbons a food energy. The effectiveness of the treatment process has several key governing factors:
- type of microbial life
- temperature of the soil
- moisture content of the soil
- gradation and soil classification
- aeration of the soil mass
- concentration and faction of petroleum hydrocarbon
Provided these above conditions are favorable bioremediation had merit for the reduction of hydrocarbons in the soil. The experience of Envirosoil, which is consistent with technical literature available, is that bioremediation is most effective on lighter end hydrocarbons, in granular soils, in warmer climates, which is partially related to the volatilization of the hydrocarbon. If timing permits, land space is available and the other factors are favorable, treatment goals of 90% may be achieved on light hydrocarbons. However, if any of the key factors are less than optimal treatment, effectiveness is greatly reduced. Especially on heavier hydrocarbon impacted soils (fuel or lube), the treatment could be closer to 50% or less. The bioremediation process has little or no effect on more complex hydrocarbons such as Polycyclic Aromatic Hydrocarbons (PAH) impacted soils.
Envirosoil acquired a Low Temperature Thermal Desorption (LTTD) unit in 1995 in order to ensure the effective treatment of the entire range of hydrocarbons and various soil types, including clay. Currently all soils are treated via LTTD to ensure timely and complete treatment of impacted soils.