I was recently asked to serve as one of the external peer reviewers of the "Canadian Water Quality Guidelines for Chloride: Scientific Criteria Document." In doing so, I documented the numerous instances where the authors were less than fastidious in checking the reliability of their references and selectively interpreted results to fit a preconceived agenda. It was a clear case where the pursuit of science morphed into ideology.
The original and subsequent iterations of the Canadian Water Quality Guidelines for Chlorides characterized it as a "Scientific Criteria Document," yet the body of the text stated that the document was "precautionary" in nature. Well, you can't have it both ways. Any document that follows the "precautionary principle" admits by definition that it is devoid of scientific consensus and, in lieu of evidence, as a precaution, asks that the burden of proof fall on those wishing to dispute the authors’ conclusions. How can such a work be characterized as a Scientific Criteria Document?
When pointing out that entirely new bodies of evidence, which significantly improved upon the accuracy and relevance of the science had not been referred to, I was informed that, in the opinion of the authors, this new science did not apply to Canadian waters - a rather odd response in light of the fact that one of the main references I used was a major Canadian mining study. Indeed, the authors' response appeared to be little more than a convoluted justification of all the positions they had taken in the original document.
In carrying out the review of the original document, I was struck by the general insensitivity of toxicological evaluations to the environment they were supposed to protect. Standard toxicological examinations do not account for the water chemistry of the bodies of water in question. The work is carried out in a controlled laboratory in liquid media that may have no similarity at all to the bodies of water in question. Comprehensive studies in Georgia by the United States Geological Survey, by the Department of Natural Resources in the state of Iowa and in Canada's Northwest Territories Ekati Diamond Mine have all found the highly significant effect of water hardness on chloride toxicity. It turns out that water hardness substantially mitigates the impact of chlorides on all sensitive species.
Standard toxicological examinations do not account for the specific animals and plants found in the bodies of water in question. Instead, it's back to the laboratory where they use a few standard organisms that may never have been within a thousand miles of the waters in question. How anyone can seriously believe that such an analysis protects the environment in the remotest way is beyond me.
What I found even more egregious were conclusions made regarding the toxicity of road salt. Yes, through runoff, road salt can make its way into the environment and that is why we have expended so much time and resources to ensure the best management of road salt. We require salt management plans, proper storage facilities, attention given to road weather information systems and the careful management of stormwater runoff to minimize any effect on the environment - just the right amount of salt at the right place and at the right time - an assembly of the very best practices.
As it happens, chloride loss to the environment is seasonal simply because road salt is used in winter. Therefore, losses to the environment mainly occur from mid-winter to early spring. This also happens to be the time when most of the biota living in streams and other bodies of water are at a low point in their growth cycle. Cold weather encourages a lag in growth and a diminution in the various organisms’ food supplies. From the few publications I have seen which studied toxicity under these conditions, it appears that organisms are less vulnerable during this period. However, back at the laboratory, this phenomenon is non-existent. The standard laboratory condition of 70ºF is kept constant throughout the year. There is no summer, no fall, no winter, and no spring - there is only the continual, comfortable, standard laboratory. There is absolutely no recognition that the organisms we want to protect live in an active, dynamic environment and that they have evolved various life and growth cycles to survive under these natural conditions.
The question is how much have we paid for environment-focused decisions made under conditions that have no bearing to reality? How is it that scientists have become so isolated from reality that they are willing to accept results that are worse than irrelevant - they are patently misleading!
It's really time to have another look at the whole imperfect science if it is to benefit us in any way.