Q: Has the frequency for the main drain testing changed from annually to quarterly?
A: Yes… but not for all the main drain test locations. The new 2012 LSC now references the 2011 edition of NFPA 25, and section 18.104.22.168 of NFPA 25-2011 requires once per quarter, one (not all) main drain test must be conducted on a system riser located downstream of the backflow preventer when the sole water supply is through a backflow preventer. This test must record the static water pressure, the residual water pressure, and the time required to restore water pressure to static pressure. This test is conducted with the fire pump off (if so equipped) and the jockey pump on.
You still must conduct an annual main drain test on all of the system risers.