Water is an essential service you must provide
A rental without running water is uninhabitable, and the obligation to restore it is immediate. When the supply comes from your own well, a failed pump is not a utility company problem, it is yours, and the clock runs the same way it does for cooling.
Pump failure is breakdown, not damage
A pump that wears out is mechanical breakdown and a standard landlord policy pays nothing. Equipment breakdown cover reaches it and is inexpensive. On a rental where you supply the water, it is among the most useful endorsements available.
A shared well needs a written agreement
Where several properties draw from one well, maintenance, cost and priority all need setting out. Many shared wells have no agreement, which means the question is answered during a failure rather than before one, usually badly.