ENVIRONMENTAL DAMAGE CAUSED BY BELOW WATER TABLE GRAVEL EXTRACTION

Last week's Wellington Advertiser carrys an article titled "Warmer water in Puslinch pit concerns local councillors".The gravel pit causing concerns is referred to as CBM's Rozell Road Pit. Information was brought to Puslinch Councillors by Stan Denhoed of Harden Environmental regarding temperature changes in both surface and groundwater.

It is Preston Sand and Gravel who are the operators of this pit which was the subject of an OMB hearing back in 2009. In 2014 CBM commenced below water table extraction which Mr. Denhoed believes contravenes the site plan which stipulates floor elevations for the pit.

There are several years of background temperature monitoring between 2005 and 2013. Temperatures of groundwater discharging to nearby cold water fisheries is being affected (warmed) most likely due to the stripping of soil and excavation of overburden. This reduces the insulating factor significantly especially when their is extraction below the water table. hence the water table (shallow aquifer) is exposed at surface and heats up in the hot summer months.

Simply put the normal environmental problems caused by above water table extraction are seriously exacerbated with exposure of normally below surface groundwater during below water table extraction. The Kuntz Pit in Winterbourne which I believe also involves Preston Sand and Gravel is currently attempting to change their operations to allow for below water table extraction. There are numerous issues with this pit including right from the start the volume of gravel available above the water table was marginal.