Groundwater Use – The Precautionary Principle

AgriLaw: March 2010

Under the Ontario Water Resources Act, no person may take more than 50,000 litres of water in a day without first obtaining a permit to take water (PTTW) from the Ministry of the Environment (MOE).  Where neighbours compete for use of scarce groundwater resources, what is the onus on a PTTW applicant to demonstrate that the proposed groundwater use will not result in contamination of adjacent wells?

The Ontario Environmental Review Tribunal (ERT) recently considered an application for leave to appeal by a municipality concerned about the issue of a PTTW to permit irrigation of a proposed golf course.  To qualify for leave to appeal, the municipality was required to demonstrate both good reason to believe that no reasonable person, having regard to government policies, could have made the decision to issue the PTTW and that issue of the PTTW could result in significant harm to the environment.

One of the relevant policies with which the MOE was required to comply in issuing the PTTW was the MOE’s own Statement of Environmental Values (SEV).  In considering the municipality’s application for leave to appeal, the ERT noted:

“ … The precautionary approach is one of the guiding principles of the MOE SEV, and … it is appropriate for the Director to apply and give effect to the precautionary approach when deciding whether to issue the PTTW.”

Citing an earlier ERT decision, the Tribunal explained this precautionary principle as follows:

“A precautionary approach presumes the existence of environmental risk in the absence of proof to the contrary.  It places the onus of establishing the absence of environmental harm upon the source of risk.  In situations where a scientific uncertainty exists as to whether an activity could have an adverse effect, the precautionary principle requires that it should be considered as hazardous as it could possibly be.”

The golf course was proposed to be located on a 55.6 hectare parcel of land surrounded by agricultural and rural residential land uses.  The single family residences located on these neighbouring properties relied on dug or drilled wells for their domestic supply of water.  The MOE had issued the PTTW without evidence of the fertilizers, pesticides, herbicides and other chemical compounds to be used in the operation of the golf course or the potential impact of these chemicals on groundwater resources and neighbouring wells.

In considering application of the precautionary principle to the issue of the PTTW, the Tribunal stated:

“ … the MOE SEV requires a ‘precautionary, science-based approach’ in its decision-making to protect human health and the environment.  The Director’s conclusion that there is no prospect of contamination from fertilizers, pesticides or herbicides as a result of water-taking under the PTTW is not based upon scientific evidence of any kind.  The [hydrogeological study submitted by the golf course owner] investigated the issue of the effect of water-taking on the groundwater supply for surrounding wells, but it did not investigate or comment on potential contamination from fertilizers, pesticides or herbicides that might result as a consequence of water-taking under the PTTW. [The MOE] relied upon evidence in [this study] to reach conclusions about water supply, but they refer to no evidence on which to base conclusions concerning potential contamination.  The extent of the consideration of this issue is the supposition of [the MOE] that ‘these chemicals typically either get tied up in the soil or are taken up by the vegetation.’  The basis for this conjecture is not identified.  [The golf course owners] evidence consists of the observation that it is not aware of contamination problems at two of its other golf courses.  This evidence is anecdotal, unscientific, and of little value.”

Accordingly, the Tribunal determined that the municipality had satisfied both tests for leave to appeal. The ERT concluded that:

“ … There is reason to believe that no reasonable person, having regard to relevant law and policies, could have come to the conclusion that there would be no contamination to local wells from fertilizers, pesticides or herbicides as a result of water-taking under the PTTW without considering scientific evidence on the question …

“Since the conclusion that there would be no contamination was arrived at without the benefit of evidence, it is not possible for the Tribunal to assess the potential for such contamination.  A precautionary approach presumes the existence of environmental risk in the absence of proof to the contrary.  Therefore, the absence of scientific evidence about the nature of the risk of contamination must result in a conclusion that it appears the decision could result in significant harm to the environment.”

Where there are competing uses for scarce groundwater resources, an applicant for a PTTW must be able to demonstrate that the proposed use will not result in contamination of groundwater and adjacent wells.  The failure to provide such evidence contravenes the precautionary principle and may result in refusal or cancellation of the PTTW