Expert Opinion

CCOB introduced our lead expert at the Stakeholders meeting held at the Ministry of Environment and Climate Change offices in Hamilton on Feb 5th 2015. This meeting is in regards to the Permit To Take Water.

Dr.  Ken Howard M.Sc., Ph.D., P.HG., P.Geo., CGeol FGS

Professor of Hydrogeology  – University of Toronto
Director of the Groundwater Research Group
Chartered Geologist and Fellow of the Geological Society of London (CGeol FGS)
Professional Geoscientist (PGeo) certified by the Association of Professional Geoscientists of Ontario
Professional Hydrogeologist (P.HG.) certified by the American Institute of Hydrology.
President of the International Association of Hydrogeologists
Lead peer reviewer for Justice O’Connor in the Walkerton Inquiry

Ken’s websites:

Ken Howard’s comments at the stakeholders meeting

[Context: Ken is speaking to the “rubbish science” that Dufferin has submitted in support of their PTTW application.] [For the full DRAFT review see this page – Ken Howard Assessment Draft Review]

Stakeholder’s Meeting – February 5th, 2015 – Dufferin Aggregates Paris Pit PTTW
Summary of Comments from K.W.F. Howard M.Sc., Ph.D., P.HG., P.Geo., CGeol FGS
University of Toronto Hydrogeology Professor and Groundwater Consultant


• I am asked half a dozen times a month to participate in these types of groundwater project.
• 80% of the time it’s clear that my opinions don’t align themselves sufficiently with the views of the potential client and I decline to participate.
• Sometimes “the alarm bells ring” and I feel obligated to make comment. This is why I’m here.


It’s actually a lot more difficult.
• If you design a rocket to exact specifications and point it in the right direction, there’s a very good chance you can predict where it will end up within reasonable limits.
• With groundwater we are dealing with natural geological systems that are inherently complex.
• For the site in question, we are dealing with potentially high risk pollutants (notably Atrazine) with a very wide but unknown mass and distribution.
• We understand even less about the likely mass, distribution and sediment concentrations of these pollutants when the “clean” aggregate has been removed and they remain on-site in a considerably more concentrated form.
• The task of assessing the extent to which these pollutants get into the water and at what concentrations is NOT A TRIVIAL TASK but it is achievable if you are willing to ask the right questions and make the effort to secure the appropriate dataset.
• Which brings me to my next key point …………….


• In the case of atrazine, we have a huge site – 260 ha (equivalent to 2.6 km by 1 km!) but only NINE composite samples from just THREE test pits, plus another FIFTEEN (or so?) composite samples from boreholes. If you don’t make the effort to look for it properly, you can’t expect to find it.
• Let us imagine we were searching for something we really wanted to find. GOLD or SILVER are good examples. We wouldn’t be collecting twenty or so COMPOSITE samples. We would be looking at the geology and collecting samples from horizons or zones where we would expect to gold or silver to occur. If those zones proved barren, then a reasonable conclusion could be drawn i.e. that the site was barren. I certainly wouldn’t be collecting composite samples from random areas where I ran the risk that the gold or silver present in the ore zones would be diluted to non-detect levels!
• Similarly, if I were really serious about finding atrazine I would be sampling below areas where I knew there had been a significant use of atrazine. I would be sampling the finer grained horizons where I might expect to find higher levels of clay, silt and organic matter (where atrazine is most likely to have accumulated). I would not limit myself to a couple of dozen composite samples! Quite clearly, the sampling program adopted by the proponents was seriously flawed.

• We also need to remember that ultimately, it will be these atrazine-rich, finer grained sediments that remain ON SITE after the aggregate has been washed and sent to market, that will dictate (through a partitioning process) how much atrazine will be transferred to the water. In all likelihood the FINES remaining on site will have concentrations of atrazine (and other contaminants) that are several orders of magnitude higher than the concentrations measured for composite samples. Nobody has any idea what these concentrations are likely to be …..NONE!… because no effort has been expended to measure them. When the concentrations of contaminant held within the sediments are raised by several orders of magnitude, the partitioning process will likely raise the concentration of contaminant in the water by a similar factor!


– the partition coefficient. The value of K dictates the extent to which atrazine (the primary concern here) partitions between the soil and the water. If K is extremely high all the atrazine will stay attached to the sediment. If K is zero, the atrazine will tend to stay in solution. It’s a crucial parameter that can be very difficult to estimate reliably.

• K will very across the site by orders of magnitude depending on the organic content of the sediment. Where the organic content of the soil is zero, then K is likely close to zero.
• In a single sample K may also vary CONSIDERABLY as a function of the soil and water atrazine content, especially as concentrations increase. It is not safe to assume that the sorption isotherms are linear (i.e. K is constant). Many isotherms follow Freundlich and Langmuir relationships.
• K is certainly not a value one finds in a book and applies to the site as a whole!
Right now, we have no reliable values of sediment organic content across the site, no batch tests and no reliable values of K. i.e. no means of reliably estimating how much contaminant is likely to partition into the water!

5) I believe there are basically three questions that need to be satisfactorily answered before washing sand and gravel at the site:

• How much contaminant (notably atrazine) do we have distributed throughout on the site?
• How much of that contaminant will eventually end be transferred to the water and
• What will be the contaminant concentrations in the water ultimately be?

If the Ministry is confident that it has adequate answers to these three questions and is comfortable that the ultimate concentrations of contaminant in the water will be “safe” (i.e. meet the appropriate standards) it should go ahead and issue the permit to take water.

Personally, I couldn’t even begin to answer any one of those questions right now given the extraordinarily weak dataset. This is why the alarm bells are ringing.

6) Key points to raise in response to any questions that may arise:

Atrazine is the primary concern at the site. Canada is 10-20 years behind Europe and other parts of the world in recognising the very serious risk atrazine poses.
Despite being requested to do so, the proponents have not made any serious effort to determine the presence and distribution of atrazine at the site. Their investigation program – design, implementation and number of samples collected is entirely inadequate.
• The greatest threat to water quality will likely occur towards the end of the pit’s life when concentrations of atrazine on the fine-grained sediment that remains on the site will be orders of magnitude higher than those at the outset. The water will be similarly compromised. By then, of course, it will be far too late to do much about the problem. The damage will have been done.
• My fundamental concern is that the proponents have not provided the data so essential for answering some very important questions about the site and the potential threat to water quality. Given the history of the site, this is no run-of-the-mill sand and gravel quarry, and shouldn’t be treated as one. It’s essential that the key concerns are appropriately addressed BEFORE the operation is allowed to proceed. This is not an unreasonable expectation.

[For the full DRAFT review see this page – Ken Howard Assessment Draft Review]