I got this from a source at the U. I don't think he (or she) would be in any trouble if I identified him by name, but he asked me not to even disclose his department. It's somebody in maintenance, the ME department, the campus PD, or purchasing. One of those.
Before the Coyles went in, the U had two choices for the fluid that runs through them: a standard propylene glycol / water mixture, or an advanced proprietary thermocoupling fluid produced by a chemical company in Albuquerque. The advanced fluid had a life span of 50 years, and was so efficient that only a little more than half the usual number of Coyles was needed. The net savings in installation parts and labor almost paid for the extra expense of the fluid, with more savings to come thanks to its much longer life span. The U crunched the numbers and the Vikings agreed to go with the good stuff from Golden Moth Chemical.
The new system was topped off, and there were still two barrels of fluid left over (it had to be purchased a dozen barrels at a time), which were then given to the Mechanical Engineering department for use in design experiments. In the spring of 2016, a brilliant but socially inept ME grad student from Colorado discovered that the non-toxic fluid worked exceptionally well as a replacement for bong water. He later shared his pipe (and its story, in excruciating detail) with a CLA co-ed at a party in a house on 8th street.
The co-ed was unimpressed with the ME grad, and had a steady at CSOM besides...but those velvety smooth pulls from that magic bong were not easily forgotten. She told her beau what she could recall of the engineer's story, something about Coyles and football. He immediately recognized the profit potential of a better bongwater. The biz kid told the story to his study buddies, including one who had a work-study gig at the stadium. Together, they hatched a plan to remove a small amount of the fluid from the field heating system to be test-marketed. A few Nalgenes full would do.
The work-study kid didn't have access to the pump room, but he could get them into a storage area in the bowels of the stadium through which the pipes traveled on their way to the field. Those were (and still are) plain 8-inch diameter PVC pipes with no joints or other access points. All they needed was a cordless drill with an ordinary 3/8 bit, plus a rubber plug and some duct tape to patch the hole. Or so they thought.
Upon breaching the pipe, the drill was torn from the poor kid's hands by the hard and relentless stream of the newly-freed fluid. They had no idea of the immense pressure required to pump the precious fluid through miles and miles of Coyles. Their puny stopper and tape were utterly useless. The kids gathered whatever fluid they could and split, leaving the remainder of the fluid to run down a floor drain.
The crime went unnoticed until the following fall, when a routine check revealed the dry heating system. It took weeks to find the tiny breach, but there was a bigger problem - the fluid was no longer on the market. Elon Musk and Tesla motors needed it to cool the battery packs in the upcoming model 3, and had purchased Golden Moth Chemical. He wasn't going to sell the U a drop at any price.
The heating system was refilled with plain propylene glycol and water, so the field is somewhat more playable in freezing weather than it was before the Coyles went in, but no longer melts snow. The alleged thieves were tracked down, but without any hard evidence they were never charged. Word has it that there are still a handful of magic bongs in circulation on the West Bank that should continue to give remarkably cool hits for the next 47 years.