Here's a link to a invitation to bid for a replacement central heating plant for Longwood.
http://tkts.longwood.edu/ifbrfp/materiel_files/214-08-HeatingPlantadd1.pdf
That implies there is an existing central heating plant, which is quite common for universities.
Buildings larger than residential quite frequently have both heating and cooling provided by either direct radiant systems, ie. radiators, or a ducted system that blows air over water filled radiators or coils. Depending on the exact system in use, they may require both heated and chilled water 365 days a year. In setting like a university campus, the water is frequently heated and cooled in buildings dedicated to that purpose and piped underground to the buildings that use it. Those pipes run through tunnels which allow access to the pipes and which may also carry electrical wires, drinking water supply, telecommunications cables, etc..
There is nothing unusual about systems like that or the tunnels go along with them. It's particularly advantageous where coal is used as a heat source and it can allow for electricity generation at the same time. Cities sometimes have similar systems which serve multi block areas, which is why steam sometimes comes from manhole covers in NYC. I don't think that's so common in cities in the west, but I'd be surprised if it isn't common on college campuses across the country.