by Mike Robinson
ABERFOYLE - Puslinch councillors are taking a “wait and see” approach regarding a recent report from Harden Environmental that suggests Nestlé’s water taking is impacting local groundwater.
The report from Harden Environmental, the township’s consultant on various hydrogeological matters, was received by councillors on Aug. 10 with little discussion - other than comments that Harden hydrogeologist Stan Denhoed was scheduled to meet with council at its Sept. 7 meeting.
Nestlé Waters Canada’s natural resources manager Andreanne Simard is also scheduled to speak as a delegation at the same meeting.
The Harden report
The report came to council as a result of Nestlé Waters’ application to renew its permit to take water at its Aberfoyle location. In the report, Denhoed referenced a number of documents, including a comprehensive report from 2011 that reviewed pumping tests and potential impacts potentially arising from the Nestlé operation.
Denhoed stated the main conclusions of that review were:
- groundwater discharge to Aberfoyle Creek is diminished as a result of the rate of water taking by Nestlé Waters and increased water taking will further decrease discharge;
- there is the potential to indirectly affect private well water quality as a result of the water taking by Nestlé; and
- there is the potential for degradation of the water quality of the Goat Island and Gasport aquifers as a result of Nestlé water taking.
With five more years of data available, Denhoed noted annual pumping at Nestlé’s Aberfoyle well increased from 588 million (2011) to 762 million litres (2015); the average between 2002 and 2008 was 720 million litres, reaching a peak in 2007 of 875 million litres.
Denhoed said the increase in pumping has resulted in lower average groundwater levels in one area pumping well and “observational trends” toward lower levels in a number of others.
“The water levels in these monitors represent the potentiometric surface of the Gasport aquifer,” he stated. “There may be climatic variations that account for the observed lower water level; however this factor is difficult to separate out from the variation in pumping volume.”
Denhoed also reported that, “We do not find similar observational trends to lower water levels (in) the wells completed in the Eramosa, Guelph or overburden aquifers.”
The report notes that data from mini piezometers (used to measure liquid pressure in a system) located within and adjacent to Aberfoyle Creek indicate both upward and downward vertical hydraulic gradients, similar to those observed prior to 2011.
Denhoed stated, “Our conclusions from the 2011 review have not changed. The water taking by Nestlé Waters Canada results in the depressurization of the Gasport Aquifer beneath the hamlet of Aberfoyle.”
He added individual wells in the hamlet may inadvertently become conduits for contaminants originating at the ground surface, septic systems or buried tanks. Denhoed noted the identification of these wells and evaluation of their quality and flow-through volumes is recommended.
Nestlé comments on report
In response, Simard stressed Nestlé has monitored the Aberfoyle Creek and its associated wetlands for many years.
“There have been no long-term changes to the flow, habitat, ecology, and fish populations of Aberfoyle Creek over this time,” she stated. “Despite the increased annual pumping in 2015, there has been no indication of changes to groundwater conditions in the vicinity of Aberfoyle Creek.”
Simard also pointed out Nestlé Waters “is not the only withdrawal from the Goat Island Gasport aquifer.”
Simard contended, “The ‘observational trends’ noted by Harden Environmental are not exclusively a function of Nestlé’s withdrawal, and ‘observational trends’ in monitoring wells furthest from the Nestlé source in Aberfoyle are increasingly subject to the influence of other water withdrawals.”
She also said water quality in the overburden, Guelph, and Goat Island and Gasport aquifers is “naturally variable” and “water quality degradation will not occur in the absence of surface contaminants, which is a collective responsibility.”
Simard concluded Nestlé “is very concerned about preserving the quality of water of the aquifers and has taken steps on its property to manage impacts to the regional water supply.”
August 19, 2016