Salt Water Intrusion in the Summerside Area, P.E.I.

Abstract

ABSTRACTSalt water intrusion is an acute problem in the coastal areas of Prince Edward Island. In the town of Summerside, ground‐water supplies are developed from an aquifer hydraulically connected with the sea. Over the past ten years, there has been progressive contamination of the aquifer, particularly in wells close to the seashore.Investigations including test drilling, aquifer testing and chemical studies were undertaken in Summerside to study the nature and extent of the salt water intrusion.Landward encroachment of the saline water is aided by the relatively high transmissivity of the fractured Permo‐Carboniferous sandstone which comprises a semiconfined aquifer. Two separate zones of salt water contamination exist—namely an upper zone from a depth of 0 to 80 feet caused by a landward hydraulic gradient of the fresh water due to heavy pumping and a second zone at a depth of 350 to 400 feet due to intermittent pumping resulting in a raising and thickening of the zone of diffusion. The extent of salt water intrusion is depicted, using hypothetical sections.