Protocol for the Derivation of Environmental and Human ... - CCME

Part D, Section 1
Where applicable, the SQG F should also be compared to an acceptable geological background soil
concentration to ensure the final value is not below background levels. Where the SQG F is below the
accepted geological background soil concentration, the SEQCCS recommends that the accepted
background concentration replace the SQG F generated using this protocol. This verification need only
be applied to the SQG F determined for agricultural and residential/parkland land use categories.
Finally, a candidate SQG F for a given substance must be checked against the current detection limit
achievable in Canada. Where the candidate SQG F is below the analytical detection limit, the SQG F
shall be set at the detection limit.
Because guidelines are based primarily on biological effects and background exposure are, wherever
possible, incorporated into the procedures, it is anticipated that very few candidate SQG F will require
adjustment. Where any of the three evaluation procedures described above does result in modification
of a candidate SQG F , this condition will be noted in the assessment document for the substance.
1.1.2 Presentation of SQG F
Development of Canadian soil quality guidelines is complex and involves many parameters. While some
parameters are known to great precision (e.g., gas content), most of them are estimates with
considerable variability. In consideration of this and other uncertainties in the guideline development
process (see Section 6, Part B), SQG F are rounded to not more than two significant figures for
presentation in assessment documents.
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