Editor: Marion E. MacCallum’s letters entitled “Fear being raised of contamination” and “Wild cranberries thing of the past” are valuable field observations about the state of the P.E.I. aquifer and Robinson’s (Rustico) Island.
For 100 years the confined aquifers have been drilled with limited understanding from Eastern Kings to West Prince. Today, the deeper circulation, that is, the waters in the confined aquifers are largely static. It takes energy in the form of a pressure gradient (field of force) to force water through sand or sandstone (field of flow); energy is required, heat is generated.
Especially harmful are deep wells at lower elevations. We have killed any offshore submarine groundwater discharge in the Gulf of St. Lawrence and Northumberland Strait. They are dead. We are now seeing many near shore problems; the near shore is dying. P.E.I. aquifers are in deep trouble.
Immediately south of Robinson’s Island are the oyster beds in Rustico Bay; everything said about clam beds applies to oyster beds. The land between South Rustico and Cymbria has an elevation greater that 125 feet and is about three km south of the oyster beds. The land gradient gives alluvial sheet aquifers in the water table aquifer a high conductivity drive into the oyster beds where the groundwater appears as bubbling springs (sand boils) and as a diffuse discharge upwards through bottom sediments. The salt water in the bay has a weak tidal drive into the sand sediments and any diffusion of salt water downward will be offset by an upward flux of nutrient rich groundwater.
On page 31 of ‘Groundwater Hydrology and Water Supply of P.E.I.’, by L. V. Brandon, Geological Survey of Canada, well 46 ‘Rustico Island Park’ is listed as being 300 feet deep; a deep well near sea level. Could this be the singular well that has consumed the cranberry bogs? If this well still exists it should not be cemented in but reworked and instrumented and used in remediation studies. Last summer an oyster fisherman reported observing abnormal clusters of oysters; likely suspects would be submarine waterborne nitrates or pesticides?