ORIGINAL ARTICLE Impact of desalination plants brine injection wells on coastal aquifers Mohamed K. K. Nassar Æ Reda M. El-Damak Æ Ashraf H. M. Ghanem Received: 10 November 2006 / Accepted: 1 May 2007 / Published online: 20 June 2007 Ó Springer-Verlag 2007 Abstract A new methodology is developed in assessing environmental impacts of desalination plants discharging brine into the ground. The main environmental problem of the desalination of seawater is the brine disposal. The brine is commonly discharged into the sea or injected into a saline aquifer. In the case of injection into the ground, it is necessary to design a disposal system in a way that respects the environment and is sustainable. Laboratory and com- putational methods have been utilized to simulate the un- steady three-dimensional (3D) phenomena of subsurface brine disposal. The computational software used is SEA- WAT, which is a 3D unsteady variable-density flow sim- ulation model. The model is first used to simulate the laboratory results, and good agreement is achieved. Then, hypothetical problems are designed and simulated of groundwater extraction and brine disposal by desalination stations. The major purpose of these hypothetical problems is to delineate a methodology and to create design charts for design and management of production and injection well fields for coastal desalination plants. Several design charts have been developed with 36 scenarios for two well configurations created by four design parameters: relative salt concentration (RSC), production and injection rates (Q d , Q r ), well spacing (S), and simulation period (T). Keywords Brine disposal  Injection well  Desalination  SEAWAT  Groundwater Introduction National policy in Egypt in recent years aims to encourage tourist investment and establishment of tourist villages and resorts in coastal areas. Whereas those sites have earned an international tourist reputation, the expansion of tourist establishments is limited by some natural constraints. One of the most important constraints is the scarcity of fresh water necessary to meet expansion requirements. Desalination of saline water is slowly becoming a reli- able and cost effective means of providing fresh water for human use, particularly in the arid and isolated regions of the world. The benefits of desalination plants that treat pumped groundwater include not only the fresh water product, but also the benefits that may occur via the low- ering of saline water table and the prevention of dryland salinity. Hence, many desalination stations have been established to feed tourist compounds with fresh water for varying objectives and uses. Desalination has long been confined to situations where no other alternatives were available (coastal towns, islands, remote industrial sites) or where energy was abundantly available (power stations, gas and oil production fields). Today, desalination is becoming a serious option for water production as alter- native for traditional surface water treatment and long distance conveyance. Desalting refers to a water treatment process that removes salts from water. It is also called desalination or desalinization but it means the same thing (Buros 2001). Other contaminants in water (e.g., dissolved metals, bacteria, and organics) may also be removed by some desalination processes (US Congress 1988). M. K. K. Nassar (&) Environmental Studies and Research Institute (ESRI), Menofiya University, 32897 Sadat City, Egypt e-mail: ma_nassar2001@yahoo.com R. M. El-Damak  A. H. M. Ghanem Irrigation and Hydraulics Department, Faculty of Engineering, Cairo University, Giza, Egypt e-mail: ashrafghanem@lycos.com 123 Environ Geol (2008) 54:445–454 DOI 10.1007/s00254-007-0849-9