Multiple rounds of testing occur when presumptions about the boundary of contamination are inaccurate. This process may repeat several times until a clean sample is found to indicate the border of contamination. On-site testing employs a series of technologies that allow for real-time soil analyses for several contaminants of concern (COC). These compounds include hydrocarbons (using ultraviolet fluorescence; UVF), metals such as lead and arsenic (using x-ray fluorescence; XRF), as well as volatile organic compounds and PCBs with other technologies.

Methods of Remediation Several on-site testing technologies are acknowledged as industry standard methods in Ontario for the remediation of contaminated sites. The most common approach to remediation is “dig and dump” or excavation/disposal remediation. As the name suggest, this method involves removing contaminated soil from a site and bringing it to a landfill for proper disposal. On-site testing allows the environmental consultant to be confident that all impacted soil has been removed before backfilling the excavation with clean soil. The volume of samples taken using on-site testing allow the AEL team to accurately identify the boundaries of contamination, reducing the likelihood of disposing of clean material. Other methods of remediation that are practiced include:

• Biological remediation, where living organisms such as bacteria are grown in the soil to metabolize or break down contaminants
• Chemical remediation, like oxidation or reduction, where impacts are chemically transformed to be non-harmful or more easily removed
• Mass transfer or air sparging, in which hydrocarbons are volatilized

Containment or barrier treatment, when a physical barrier is put in place to keep contamination to a limited area and prevent spread.