CRA ARE AS TRICKY AS EVER

Currently Conestoga Rovers on behalf of Chemtura are "investigating" GP1 & 2 on the south-east corner of their site. According to their two work plans dated June 30 and July 28/11 they "...will excavate the test pits to a minimum depth of 4 metres below ground surface (mbgs), the top of the UA1, or the maximum reach of the excavator bucket, whichever comes first.". They have massaged the wording very slightly in their July 28/11 Work plan which is what caught my attention. The June Work plan evoked my response "well just get a bigger excavator". Afterall the depth of the excavation should be based on what you are finding as you dig, not on an arbitrary reach of an excavator bucket. After rereading the two reports I now understand that the real issue is the top of UA1 (Upper aquifer 1). CRA over the years have produced numerous stratigraphic cross-sections. Both David M. and Ron C. on the new CPAC will be familiar with what these are. Unfortunately unlike myself they do not have a twenty year plus library of technical documents produced by Uniroyal/Chemtura consultants.

Stratigraphic cross-sections are drawings of the below ground makeup showing things like clay layers, sand and gravel layers etc. They show a cross-section (sideways view) of what is below . I've looked at several produced by CRA and they all show that in the south-east corner where GP1&2 are located there is no fill or surficial aquitard. The UA or upper aquifer is present right at the surface. One of these cross-sections runs from OW69 through to CH19 or in other words a significant length of GP1. The other cross-section runs from CRA3 through to CH19. This is on the extreme southern border of Chemtura , parallel to GP2 and literally only a few metres below (south) of it. Hence CRA's Work Plan says that they will excavate the test pits to the top of the UA1 which is ground surface. Later today or tommorrow I will e-mail these cross-sections to all CPAC members.