@Des Prosser  I have not ...

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@Des Prosser 

I have not (unfortunately for me) ever made it to Nashville.  Perhaps it was somewhere else, such as a conference meeting in Austin, TX.

One more thing no one has mentioned for cooling water conservation is the combination of wet/dry cooling tower, where most all of the heat rejection is by dry air, followed by smaller evaporation load.  After all (if blow-down is even marginally under control) the lion's share of the water goes to evaporation.  Another water conservation item would be to totally be rid of the Rankine cycle altogether, substituting something like the closed super-critical carbon dioxide Brayton cycle (also known as Allam cycle).  Allam cycle can be successfully applied to coal, or natural gas combustion, Closed Brayton SCC cycle can also work with nuclear fission (or someday with fusion?) as heat source, or CSP (concentrated solar power).  Since no combustion takes place in the latter cases, one may not properly refer to these as Allam cycle.

SCC Brayton cycle is very amenable to air-cooling only, since one does not rely on phase transition from gas (vapor or steam) to liquid, but rather from relatively low pressure, warm dense fluid, to cooler dense relatively low pressure fluid.  The compressor in SCC Brayton cycle looks more like a pump than a compressor.

 

Getting back to systems out of control, I have seen a place with a high throughput, large cooling tower operating on very hard well water with high silica content, but using cold lime softening clarifier only (and that grossly undersized), with such solids accumulation in a holding pond that islands were forming.  OMG.  One could not believe the stalagtites created by mineral precipitation in the wet-dry areas of that cooling tower!  Various suggestions have been made to provide them with ZLD system (rather than the 40 cycles of concentration they are running), with no issues, other than fair wear and tear of upstream water treatment.  I don't see anyone buying anything, but the bean counters are running the world now.