Need a Fire protection Sprinkler and no city water supply ? Introducing the Pressure Tank for these situations

Recently I picked up a large church expansion job which needed a Fire system and also had to have a Sprinkler system as well . normally not a big deal but this church sits in a rural section of butler county and there is no city supplied waterline only a well providing water to the church.
OK so whats the solution to having an available water supply its called a Pressure tank as seen in picture below.

In this case a 10,000 gallon tank the size of a railroad car  was required which is filled 2/3 full with treated water and then 100-150 pounds of air pressure is maintained on tank by a small air compressor you see in left of picture  and pressure to tank is monitored by  a supervisory fire system switch for air pressure loss.    The tank  is attached to sprinkler piping and
when one of the heads activates the pressure in the tank will supply the sprinkler heads for 5-10 minutes time  and fire alarm will activate via the flow switch on piping  and notify fire dept.
When fire dept arrives with there engine they set up a small pool which there tanker truck and other arriving tanker trucks dump there water  into which engines suctions out and is then attached to the FDC Fire dept connection which will then continue to feed the sprinkler system till fire is put out .
a similar but much smaller tank is used for residential systems where a well is involved .
While adding the tank and pump adds significantly to cost of a sprinkler system it solves the problem for now till this community gets big enough city water will be brought to it or better way of putting out fires is developed. While 5-10 minutes may not seem much in the way of protection often fires are put out or controlled greatly so they are quickly put out upon fire dept arrival