5. The process as set forth in claim 1, wherein said feed water stream contains more alkalinity than multi-valent metal cations, and further comprising, before feeding said feed water stream to said cation ion exchange system, the step of addition of acid to said feed water stream, so as to remove the excess alkalinity in said feed water stream. 

6. The process as set forth in claim 1, wherein the step of multi-valent metal cation removal is accomplished by passing said feed water stream through a sodium form strong acid cation ion exchange system. 

7. The process as set forth in claim 1, wherein after remov› ing substantially all non-hydroxide alkalinity from said feed water stream dissolved gas is removed from said feed water stream. 

8. The process according to claim 1, wherein said evapo› rator is falling thin film evaporation equipment operating as a single unit or in series or parallel, or forced circulation evapo› ration equipment which operates as a single unit or in parallel, or natural circulation evaporation equipment which operates as a single unit or in parallel, to generate said distillate stream and said high solids blowdown stream. 

9. The process as set forth in claim 8, wherein said evapo› rator is operated in a steam driven multiple effect mode, or a mechanical vapor recompression mode, or a thermal com› pression mode, or as a multiple stage flash evaporator. 

10. The process as set forth in claim 1, further comprising 25 heating said feed water stream to enhance gas removal in a degasifier prior to entering said evaporator. 

11. The process according to claim 1, wherein the step of raising the pH is accomplished by addition of a base in aque› ous solution, said base selected from the group consisting of sodium hydroxide, sodium carbonate, potassium hydroxide, and potassium carbonate. 

12. The process according to claim 1, wherein the step of raising the pH is accomplished by addition of an aqueous organic base. 

13. The process according to claim 1, wherein said feed water stream is cooling tower blowdown, scrubber blow› down, water utilized in ash transport in a coal fired steam› electric power plant, ash pond water, ash-sluicing water, effluent from sewage treatment, effluent from a food process› ing treatment, boiler blowdown, a concentrated stream from membrane separation equipment, effluent from oil refining operations, or effluents from hydrocarbon recovery opera› tions. 

14. The process as set forth in claim 1, further comprising, during the step of removing alkalinity, the additional step of removing substantially all non-hydroxide alkalinity not asso› ciated with hardness. 

15. The process as set forth in claim 1, wherein after step ( c) (II) and prior to step ( d), the process further comprises the step of removing dissolved gas in a degasifier. 

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