Abstract: A control method for controlling the intrusion of dissolved solids into a fresh water aquifer located proximate to an ocean includes the steps of: a) frequently measuring the TDS content at a control location, such frequent measuring of TDS content at the control location being conducted at least about once per calendar quarter, the frequent measuring of TDS content at the control location providing a plurality of control location TDS content values; b) comparing one or more of the plurality of control location TDS content values to a predetermined TDS control range; and c) adjusting the TDS content at the control location to within the predetermined TDS control range by one or more control measures.

Abstract: A system for reducing salt water intrusion into a fresh water aquifer includes: a) generating means for removing brackish water from the aquifer via an brackish water extraction well at a first distance from the ocean; b) removal means for introducing the removed brackish water into a desalination system to generate a first stream of water with a first salt content and a second stream of water having a second salt content, the first salt content being less than the second salt content and less than the salt content of the removed brackish water; and c) introduction means for introducing at least a portion of the first stream of water into the aquifer via a barrier well at a second distance from the ocean, the second distance being greater than the first distance.