You do not state the geographical position of the developing countries but if we assume there is both an abundance of sunshine and reasonable space available for a STP, I would suggest the implementation of stabilisation ponds. These consist of a series of shallow ponds, usually a minimum of...
The milky appearance is a result of dissolved air / carbon dioxide coming out of solution which has resulted from a greater saturation value due to the increased depth of the well. This will invariably clear with storage but you should check the pH to ensure the water is within safe drinking limits...
You do not state if your discharge restrictions are due to brine concentration or volume. If it is the former have you considered reducing the concentration by diluting the brine with cooling water or another source if so you will need to mix the two products thoroughly. We have found...