Press Release

Landfill Site 41 Community Monitoring Committee

July 17, 2007

Simcoe County Refuses to Release Model to CMC

Tiny Township

The County of Simcoe has refused to provide the Site 41 Community Monitoring Committee (CMC) with a copy of the mathematical model used by the County in estimating groundwater conditions at Site 41. When contacted for comment, CMC Chair Ray Millar stated, “We were, of course, disappointed at the County’s response and rather surprised too. We expected that it would be available to a citizens group such as the CMC in order to assist us in our on-going evaluation of the perceived risks posed by a landfill at Site 41.”

Modeling is often used in place of lengthy and costly physical field study but it is not without its critics. United States Geological Survey Geologists Leonard Konikow and John Bredehoeft have written an award winning paper entitled “Ground-Water Models Cannot Be Validated” and Groundwater Consultant Dr. Stuart Rojstaczer has suggested that the results of groundwater modeling should be “transcribed to the back of an envelope.” Dr. Rojstaczer suggests that by putting the results on the back of an envelope, it would signify to the user just how risky the numbers are. The model used by the County at Site 41 is the United States Geological Survey MODFLOW.

At the June 14 CMC meeting, Simcoe County Environmental Services Manager Rob McCullough commented that the request for the model by the CMC sounded reasonable and that he could likely authorize it, pending Council approval. It was only after several follow up requests by Mr. Millar, that Mr. McCullough responded via email stating, “After fully discussing the CMC’s request for the MODFLO model with Senior County Staff and the consultant (JAGGER HIMMS), we are not in a position to approve this request.” Mr. McCullough went on to explain that the MODFLO is a “complex and complicated tool” and the “output of the model is sensitive to the calibration conditions and even minor changes in the settings could vary the results.”

It was the CMC’s intention to have a qualified consultant, Dr. David Charlesworth, take the model as presently calibrated, and test out some additional scenarios with regard to changes in recharge. “Given the importance that the County has placed on the results of the modeling, we would hope that the model was sufficiently robust to withstand this kind of evaluation”, said Mr. Millar.

The CMC’s request for a copy of the functioning model in its final calibrated form is not without precedent. There are other cases, both within and beyond Ontario, where the party which commissioned a groundwater model, has made that model available to other interested parties. This is usually seen as evidence that the owner of the model has confidence in that model and believes that it will stand up to close examination. Refusing to allow others access to the actual model might be seen as evidence of lack of confidence in that model.

The County’s admission that even minor changes in the settings could vary the results does not give the CMC confidence in the predictions which have been made on the basis of the model. While it is true that the output of the model has been peer reviewed, the veracity of the input data never was and no model can overcome a series of bad assumptions. Mr. Millar points out that it was mathematical modeling that determined the limit of sustainable cod fishing. According to those modeling efforts, the Grand Banks should still be teeming with cod.