Not sure if it's possible, but it may be good to restrict this to not work when placed on concrete. I've been using them inside Factorissimo buildings, and I have to say, it's starting to feel a bit cheaty. I can just plonk them down anywhere inside these factories to solve the water issue and never have to worry about routing pipes or anything. However, if I could ONLY place them outside (factorissimo are all floored with concrete) then I could place the wells outside the buildings and route power in still, and maintain the necessity to route water within the buildings.

Hi,

yes the whole think is a big cheat :)
I don't think it would be easy to pre-check if there is a concreted tile under it and i must point you to the FAQ.

Sorry, steinio.

If you feel like it's cheating to place them inside of factorissimo buildings, then don't put them there unless you're okay with feeling like you're cheating.
Also, I believe that your suggested restriction also wouldn't work to resolve your issue since factorissimo buildings, as far as I can tell, use their own tiles