Is desalination of seawater considered more economically viable than desalination of saline ground water?

Is desalination of seawater considered more economically viable or 'sustainable' than desalination of saline ground water, given that the second method may also aid in alleviating salinity? Thank you.

Taxonomy

• Economics
• Groundwater
• Saline Water
• Desalination
• Sea Water Filtration
• Sea Water Desalinisation
• Sustainable Desalination
• Finance and Markets
• Groundwater Resource
• Economics & Policy
• Finance
• Economics
• Green Economics
• Desalination

3 Answers

1. The simple answer is, the cost of desalination, regardless of  method is directly proportional to the TDS of the feedwater.   There are many other factors involved however such as the cost of delivering the feedwater to the desal system.   Consider the desal system as box that receives water on one side from any proposed source, processes and delivers a suitable product our of the other side of the box.  Plug in all the basic parameters and that should give your a good start.   Then of course there are plenty of qualified persons who have typically 30 to 50 years of experience in all aspects of desalination who make their living providing the very best solution.

   A major consideration for tapping brackish sources is the fact that they are finite and can have repercussions when depleted whereas seawater is infinite.

2. I tend to say that, in the end, desalination of seawater is more expensive. Desalition of brackish groundwater has many advantages. I made a recent study that summarizes them (attached).

3. Desalination of sea water desal vs brackish groundwater
   
   As usual the answer is IT DEPENDS :-) It depends mainly on processes involved (energy and chemical consumption) - here you can find good and bad solutions for both sea water and ground water desal - and waste streams generated and how they are treated/disposed. Waste streams are very saline, often have significant chemical concentrations and occur in large volumes (usually a similar amount as desalinated water). In inland areas (brackish groundwater desal) this is usually a challenge, since this wastestream often cannot be pumped back to the aquifer. Big evaporation ponds are frequently used instead. At the sea, one can often design a proper hydraulic solution that disperses the brine effectively in the sea. Yet, in the mixing zones high salinity and chemical concentrations can still create severe damages to some sensitive ecospheres. Doing a proper assessment, followed by a proper engineering design and the use of davanced technologies should overcome the challenges listed above. Helge