Water Table
The water table near the library is only 4 feet below ground, so they have it drain into a 500 gallon tank which is pumped out every 5 minutes or so. This ground water is pumped right up to the city storm water system and is useless to them. We can make this water useful and even save them energy (and money) by using it to prechill the air.
Here's how it would work. Right now to cool the building, air is blown through a coil of cold water pipes and then sent to the rest of the building. This cold water is cooled in an electric chiller. We can pump the ground water through another coil before the chilled water coil. This will make it so less cold water from the chiller is needed, reduce the load on the chiller and use less electricity.