On July 23, 2008, the Ontario Court of Justice released its reasons in R. v. Inco Limited (Court file no. Sudbury, 96-615) [2008], ONCJ 332 (CanLII), a case which involved charges under Section 30 of the Ontario Water Resources Act (OWRA) related to an untreated mine effluent (to a creek) and the failure to immediately report the discharge. The court dismissed both charges against Inco. In the course of doing so, the court provided guidance on the test to be applied in determining whether an effluent containing metals is capable of impairing the quality of waters to which it is discharged. The court accepted Inco’s argument that it is necessary to look at the amount of bioavailable nickel in the discharge, rather than the total quantity of nickel, to determine whether the discharge is capable of impairing water quality. The decision provides important guidance concerning the water quality standards that metals must meet in order to not violate Section 30 of the OWRA.

Section 30 of the OWRA prohibits the discharge of any material into any waters or in any place that may impair the quality of the waters:

30. (1) Every person that discharges or causes or permits the discharge of any material of any kind into or in any waters or on any shore or bank thereof or into or in any place that may impair the quality of the water of any waters is guilty of an offence.

The accepted test for determining whether water quality has been or may be impaired for the purpose of Section 30(1) of the OWRA was described by the Ontario Court of Appeal in an earlier proceeding in this same case. The Court of Appeal accepted a zero tolerance principle for inherently toxic substances, but found that for materials that are not inherently toxic, the other circumstances of the discharge must be considered. For example, the discharge of an inherently toxic material, such as polychlorinated biphenyls (PCBs), constitutes an offence under Section 30(1) regardless of the amount and circumstances of the discharge. However, the discharge of a material that is not inherently toxic, such as sand or silt, requires that the quantity and circumstances of the discharge be considered in order to determine if water quality has been impaired.

In this case, the court agreed that nickel is not an inherently toxic substance and that it is therefore necessary to look at the circumstances of the discharge in question to determine if the discharge may have impaired the quality of water. While sampling revealed elevated levels of total nickel in the effluent, Inco took the position that only a small portion of the total nickel would have been present in a harmful form (i.e., as bioavailable nickel). The Crown argued that total nickel was the critical factor and that, in this case, the total nickel concentration in the effluent was much higher than the Provincial Water Quality Objectives for nickel, indicating that water quality may have been impaired.

Following the presentation of large amounts of scientific evidence by both parties, the court accepted Inco’s position that the key factor was the concentration of bioavailable nickel — and that the evidence showed that, in this case, the amount of bioavailable nickel was not sufficient to cause impairment. The prosecution’s evidence was based on total nickel concentration, as opposed to the nickel that was bioavailable, and was therefore not indicative of whether water quality was impaired.

The court also accepted Inco’s position that the Provincial Water Quality Objectives for nickel, which the prosecution was using to demonstrate impairment of water quality, were developed on the basis of exposure to bioavailable nickel, not total nickel. As such, the court concluded that "There is good reason to question the usefulness, the significance and the fairness of testing total metal concentration in samples when the Provincial Water Quality Objectives or any other objectives that set concentration limits are based on bioavailable metal."

In this case, comparing total nickel concentrations to the Provincial Water Quality Objectives, which are based on bioavailable nickel, was not informative of water quality impairment.

McCarthy Tétrault Notes: 

The court’s decision reflects a growing international practice that rejects the "total metal" analysis and instead looks at the amount of metal that is dissolved and bioavailable, and therefore capable of affecting organisms. Companies are often faced with the difficult task of determining whether a particular discharge has or may contravene Section 30 of the OWRA. In the case of discharges containing metals, this decision provides important guidance by concluding that "distinguishing between metal speciation is essential to a proper assessment of impairment of water quality."

Doug Hamilton was counsel for the accused, Inco Limited, in the above-described case.