The bioremediation process can be performed insitu or exsitu. The insitu process is adopted where excavation is impractical and involves either bio-stimulation or bio-augmentation.

Biostimulation involves aeration and the application of selected micronutrients and bio-stimulants. Bio-stimulation is only effective when indigenous microbial populations, present in the substrate, are high enough to degrade the contaminants and when these microbes can readily adapt to foreign contaminants.

Bioaugmentation involves the application of beneficial microbes, that have an affinity towards a specific contaminant. Typically, these microbes are suspended by a stabilizing agent and lie dormant in a spore until activated in solution and applied together with micronutrients and bio stimulants. 

BIOREMEDIATION can effectively degrade the following contaminants:
Hydrocarbons with carbon chains ranging from C-5 to C-40
Benzene, xylene and toluene
TCE
PAH
PCB and other chlorinated compounds
Fuel oils
Fossil fuels - gasoline, diesel, aviation gas
Condensate - leakage from pipelines
Glycols

BIOREMEDIATION BENEFITS
Thorough degradation in a relatively narrow time window.
Simultaneous multiple activity
Toxin resistant
Reduced risk / higher degree of safety
Reduced labor and equipment costs

DATA required to develop a proper bioremediation protocol
Age of the spill
Localization  
Soil Type 
Spoil porosity 
Soil pH 
Soil temperature
TPH
Viscosity and volatility of contaminants 
Depth of contamination 
Soil moisture level
Oxygen availability

CASE HISTORY

MTBE CONTAMINATED SOIL 
Vapors, resulting from this spill, created an explosion and respiratory hazard. A microbial formulation was applied to the affected area. The vapors were suppressed immediately upon application and, in a relatively short period, the contaminant was digested. Subsequent cleanup was not necessary. 

PIPE AND SURROUNDING SOIL CONTAMINATED WITH DIESEL
The free diesel was pumped out of the pipe and a microbial formulation was applied to digest the residual contaminants. The same product, together with bio-stimulants and micronutrients, was applied to the soil. Twenty-eight days after the initial treatment, TPH levels dropped from low thousands to low hundreds. In one case TPH levels dropped to 43 ppm.

CRUDE OIL SPILL IN A TANK FIELD
The crude oil was pumped out and the soil and grassy area treated with a microbial formulation together with micronutrients and bio-stimulants.  Eight weeks after the initial application, TPH levels dropped from low thousands to low hundreds. In one case TPH levels dropped to 39 ppm.

DIESEL SPILL IN A PIPE
The free diesel was pumped out and a biological formulation together with a bio-stimulant was applied to degrade any remaining contaminant. Within 4 weeks TPH levels dropped from a range of 25,000 - 57,000 ppm to a range of 600 - 9,900 ppm. 

SOIL, UNDERNEATH A STORAGE TANK, WAS CONTAMINATED WITH GASOLINE DUE TO A LEAK IN THE TANK BOTTOM
The remaining alkylate (gasoline blend) was removed from the tank and a biological liquid  was introduced into the tank and allowed to travel through the same path as the alkylate. Within three weeks, the TPH levels, in the soil underneath the tank, was reduced from a range of 200 - 600 ppm to a range of 30 -130 ppm. 

EMERGENCY RESPONSE TO ACCIDENTAL GAS RELEASE
A suction drum on a compressor began to fill with oil and had to be drained to the contaminated sewer to protect the equipment. Typically, this would not pose a problem, since the contaminated sewer enters an oil/water separator where the oil is captured. However, unknown to the technicians, the oil contained entrained hydrocarbons which broke free of the oil resulting in a gas release, when the oil entered the sewer system.  To mitigate this problem and reduce the threat of  fire and explosion, a microbial formulation was applied to the sewer. Within two hours of application, the hydrocarbons were reduced to non-detectable levels. 

EMERGENCY RESPONSE TO MTBE SPILL
An MTBE tanker was overfilled when the automatic shutoff valve failed. The loading rack was equipped with a secondary containment system that drained to a holding pond. The amount of MTBE collected by the system was estimated to be approximately 2,400 litres. While the MTBE was contained, the vapours from the containment system were both irritating to personnel in the vicinity and explosive. A hand line and eductor were used to apply a microbial formulation to the pond. Within one hour, the vapours were detectable only within a few feet of the pond. An additional amount of product was applied to the pond at that time. One hour later MTBE levels in the pond were non-detectable. 

CLEANING DISTILLATION TOWERS 
Typically, preparing towers for turnaround, using conventional methods, is labor intensive. Standard procedures call for the towers to be washed with water and drained several times, steamed  and wash again. Under certain conditions, towers that have gone thru an intensive cleaning process, will contain elevated levels of contaminants. 

Treatments were carried out using biological products including, surfactants, micronutrients and bio-stimulants, in the wash portion of the tower. To optimize product efficacy and reduce application rates, eductors and pumps were used in the application process. The end result was complete decontamination and a significant reduction in cleanup time.

CLEANING EXCHANGERS, LINES & PUMPS
Trials, have shown that oil, trapped in the high points of exchangers, lines, pumps, etc., can be totally removed and the units decontaminated with the use of a biological solution. The decontamination process involves applying the solution and letting it sit for 1 to 3 hours. Circulating the product through the equipment can significantly reduce cleanup time.

ELECTRICAL BOX CLEANUP
A fuel oil spill contaminated an electrical junction box, cables, the concrete wall to which the box and cables were attached and the surrounding soil. A microbial formulation together with micronutrients and bio-stimulants was applied to the wall, junction box and cables and within 48 hours decontamination was complete. A similar solution was applied to the contaminated soil and within 18 days contaminant levels were undetectable.