Limited impact release (occurrence)

A spill or release of a contaminant can be dealt with in two ways, as a Limited Impact Release (LIR) through the occurrence system or as a Contaminated Sites Management file (see the Contaminated Sites Management process). In general, a spill may be handled as a LIR (occurrence) if the release is current (not historical contamination), only the soil is contaminated, there are no impacts to groundwater or ecological receptors, and the spill can be cleaned up within 30 days.

When a spill or release of a contaminant is reported to the Regional Office the Inspector will open an Occurrence file. The Inspector may visit the site, depending on the magnitude and severity of the incident. For most spills or releases, the Responsible Party will be directed to engage a Site Professional to manage the incident. Once the Inspector has sufficient information, they will conduct an incident screening to determine if the spill can continue to be managed as a LIR (occurrence) or if the file needs to be transferred to the Contaminated Sites Management Process (see the Contaminated Sites Management process). If it has been determined that the spill or release incident can remain as a LIR (occurrence), then the incident must be cleaned up to the satisfaction of the DELG Regional staff. Following site clean-up, the Site Professional overseeing the work should submit a summary report of the work that was completed to the Inspector. The incident summary report should contain sufficient information to allow the Inspector to close the LIR file (occurrence).

This incident screening guidance is used to determine when a spill or release event may be managed as a Limited Impact Release (LIR) file (occurrence) or needs to be registered as a Contaminated Sites Management file. The Inspector will evaluate the site-specific conditions and may request information and/or a professional opinion from the Site Professional on potential impacts to groundwater and/or ecological receptors.

Generally, the following criteria should apply for the incident to remain as a LIR file:

1) Either of the following:

a) Spill is contained on an impermeable surface (i.e. asphalt, concrete pad/floor, etc.) and/or in an isolated area with no potential for human health and/or ecological impacts (e.g. motor vehicle accident, parking lot, vacant lot); or

b) A spill event that requires no further remedial measures other than:

• short-term actions to protect human health and the environment (e.g. spill containment, free product recovery); and/or
• soil excavation

2) There is no staining remaining at surface after initial remedial action(s), which is defined as <30cm below the ground surface.

3) Spill resulting in the removal of less than 75 metric tons (approx. 5 tandem truckloads) of contaminated soil (note that contaminated soils must be disposed of at an approved facility). For incidents that are located in a remote area or sections of roadways where no residential dwellings are present, the removal of greater than 75 metric tons of soil may be considered if all other criteria are met.

4) The contamination has been removed within 30 days and meets applicable Tier I criteria within the excavation (i.e. confirmatory and representative samples);

5) Groundwater is not impacted or not likely to be impacted at the subject or adjacent properties.

If the Inspector determines that the spill/release event does not meet the above criteria then the file should be transferred to the Contaminated Sites Management process.