A very rusty (nearly all the way through) sprinkler pipe was discovered in the LSB interstitial yesterday. The pipe had a very minor leak where the down leg screws into the 90 degree ell and finally formed enough rust and calcium deposits that started deteriorating the pipe from the outside in. I have isolated the system and will replace the pipe. 

I have also filed an FRS and will also input this into the FAMIS system for quarterly checks of the entire system. 

Until the pipe is replaced, hopefully today, the LSB will be without automated fire protection, all pull stations will still alert the fire department.