The pool costs money to operate so they're just making sure peopole aren't stealing from them. Can't have non-EK people swimming in the pool and using it up.
This is the same DSO pools they don't put chlorine in (because it costs too much).
Regular cases of GIARDIA at DSO because people let their kids !!!! in the pool or wear dirty nappies and "someone" is too tight to pay for chlorine.