Leveling Renewable Power with Sewage Plants

Building on the post about building my dream doomsday bunker, while using more of an eye towards 

rationality I would like to present an idea that I hope is pseudo original.  At this time pumped hydropower is still considered one of the most cost effective ways of storing power.  What is suggested here is using existing waste water facilities as a possible source for the water that is pumped into the storage lake.  The logic of this approach comes from a few key factors, the first comes from the established "ruined view", as sewage plants are rarely considered aesthetically pleasing, it would be reasonable to assume that developing a pumped hydropower facility near a sewage plant will have fewer NIMBY issues (not in my back yard).  The Second consideration also deals with sight availability, while proposals for using pumped hydro already exist, deployment options are limited by the availability of water that can be used for the storage water, by utilizing recently purified waste water, you allow more usage from a given unit of water before it is returned to the watershed or reserve aquifer.  Realistic modeling of the ROI of a technology like this are well beyond my current resource portfolio but I would be curious to see if this solution might turn out to be economically viable for some markets.

March 13  Another Feature that could be considered for this configuration, to a lesser extent the compressed air storage facility suggestion, would be to augment the facility's revenue stream by providing space for a decent sized server farm.  The synergy for the server farm would stem from being as close as possible to an extremely reliable supply of electricity and relatively cool water to mitigate the need for more active cooling solutions.  For the facility operator there would be the benefit of having a guaranteed inbuilt customer for some percentage of their output.  Additionally depending on how a facility like this was constructed it wouldn't be unreasonable that if the storage lake's altitude was partially a product of it being of artificial construction, building in a certain amount of industrial volume wouldn't be too unreasonable.
On the idea of making the storage lake artificial, as it isn't different enough for a full on post, a pumped hydro facility built out of an old landfill, waste storage site, etc.. could help make it a very long term solution for a range of problems.