RE: “The science of gravel extraction,” Jan. 24 Brant News,  Dufferin Aggregates Watts Pond Road Paris gravel pit proposal.

In his response to the concerns that I raised with reporter Jason Teakle regarding the potential release of pesticide residues by the aggregate washing process, Kevin Mitchell of Dufferin Aggregates is reported as stating: “There is no known example of an aggregate operation resulting in groundwater contamination of a municipal supply.”

The following is taken from The Ministry of Natural Resources 2006 report “Applied Research on Source Water Protection Issues in the Aggregate Industry Phase l Findings:”

“Comments were made in several publications that having no documented instances of water quality impacts from aggregate operations could also be due to lack of monitoring.”

It is appreciated that Dufferin Aggregates (Holcim Canada) has made its monitoring data on water quality available to the public. However, the data does not include any test results for pesticide residues either in the water or in the ground of the site. If not, why not?

The County of Brant does test the well water for pesticides and the Paris supply does comply with current standards. The concern is that compared to the present natural slow and diffuse leaching, which may not be giving rise to elevated levels that exceed maximum concentrations, the washing process clearly has the potential to both accelerate and concentrate residue levels at a single entry point in the aquifer.

Consider the following:

At our farm, on the outer edge of Paris well head protection areas, we were pleased to receive grant aid from the GRCA and County of Brant for the decommissioning of an unused small three-foot diameter, 19-foot deep shallow well that is considered under source protection to be a transport pathway for potential pollution to the Paris drinking water supply.

It is a very publicly visible contradiction if at the same time in the same aquifer close to the Paris wellheads a 12.5-acre source pond will be excavated below the water table.

The pond, a very large new transport pathway, will receive wastewater from the washing of almost a million tonnes of aggregate per year. This apparently without any required prior studies to determine the level of contamination in the ground. Gravel washing is not an activity “that happens to be taking place on the site,” as the Ministry of Environment put it.

Perhaps Dufferin Aggregates will agree to forego the privilege of a 1974 licence and assess this potential risk in a public study using scientifically agreed detection limits and methodology before commencing pit operations.

It would be a straightforward application of the precautionary principle as recommended by the Walkerton Inquiry and show respect for a level of due diligence that the people of Paris are surely entitled to expect.

Nick Greenacre
Paris