Tuesday, April 3, 2012

STRATIGRAPHY OF GP1 AND GP2



First off GP1 & GP2 stands for Gravel Pit 1 & 2. These are the locations at Uniroyal/Chemtura of the highest Dioxin concentrations in Ontario and possibly Canada. The expansion to Canada is based on the ever increasing concentrations that are being found there. Stratigraphy refers to the sub surface makeup of the ground. Just by the name (gravel pit 1 & 2) it's pretty obvious that we have sand and gravel present. GP2 is closest to the Canagagigue Creek and would be no more than sixty feet from it at it's closest point. Although there are literally dozens of reports over the years showing the sub surface stratigraphy of this area the easiest one for CPAC members to access might be the recently released (Feb 2012) 2011 Annual Monitoring Report Volume II Figures and Tables. Specifically Figures 2.5 and 2.1 are the pertinent ones. The only reason I'm including Fig. 2.1 is because Conestoga Rovers (CRA) as is their habit have made another boo boo on Fig. 2.5 by labelling UA as Upper Aquitard. For the last twenty-three years on this site, UA has stood for Upper Aquifer as it does in Fig. 2.1 . The significance of Fig. 2.5 therefore is that this stratigraphic Cross-Section clearly shows that the UA or Upper Aquifer is right at the surface on the east side of the Canagagigue where GP1 and GP2 are located. This also corresponds to the sand and gravel found in these gravel pits. Sand and gravel of course are the very best materials for groundwater to flow readily and easily through. Going back to Fig. 2.1 we can see that most of the rest of Elmira has an aquitard known as the SAT or Surficial Aquitard. Aquitards are made up of tightly compacted silts and clays and inhibit the flow of either surface water downwards or groundwater horizantly or vertically.

The significance of this stratigraphy is that solvents which mobilize Dioxins and DDT and which are on the Chemtura site in abundance are moving through this GP1 & 2 area and discharging into the creek. There is zero natural protection from an aquitard which would inhibit groundwater and contaminant flow. This area is also of low elevation and is floodplain which could easily mean surface water from the creek in springtime can rise and erode soils thus releasing more Dioxin into the Creek. Therefore the presentation by CRA at last week's public CPAC meeting was mainly wishful thinking. When CRA suggest that the only receptors are shrews and trespassers, they are ignoring the obvious. All the Dioxins found downstream in the Canagagigue came from both Uniroyal groundwater discharging to the creek as well as erosion of Dioxin laden soils in and beside the creek.

No comments:

Post a Comment