Project Description

The site is located on the west coast of Barbados, 2km south of Holetown and slighty east of Highway 1.

The main geological unit in the site area is a Coral Rock Formation which is overlain along the coast by marine beach and modern dune deposits. The hydraulic conductivity of the Coral Rock Formation on the site was found to range over more than one order of magnitude, between 3×10-4 to 7×10-3 m/s, and it has a geometric mean of 1×10-3 m/s. The Coral Rock Formation is underlain by the Oceanics Formation, a sequence of low permeability marly beds forming the base of the active groundwater flow system.

The pumping and injection well fields are on the southwest edge of the original golf course at Sandy Lane Resort. At locations and depths selected by others the production wells were drilled to provide a saline groundwater supply for the desalination plant, and approximately 130m to the south injection wells IW1B, IW2 and IW3 were drilled to discharge brine from the desalination plant into deep coralline rock above the Oceanics formation.

During the period October 2000 to January 2001 pumping tests were conducted on four production wells (PW1, PW2, PW3, PW4) and one injection well (IW1B). The test results were used to assess the performance of the wells and to determine the hydraulic characteristics of the coralline aquifer. A brine plume study was undertaken to review the pathway and receptor areas for the brine. The long term pumping rate of the production wells should be designed such that it does not impact the freshwater or brackish water layer in the coastal zone. The brine pumped into the injection wells must undergo sufficient concentration reductions along its pathway to the coast and offshore seabed that it does not have a negative impact on aquatic life in Sandy Lane Bay located 350 m west of the injection wells. The location of the injection wells should be such that the brine plume will not be drawn back into the production wells during the long term pumping.