Mediation shall terminate:
(a)
At any time the Federal and State agencies agree to a resolution of the serious disagreement,
(b)
If one of the agencies withdraws from mediation,
(c)
In the event the agencies fail to reach a resolution of the disagreement within 15 days following Secretarial conference efforts, and the agencies do not agree to extend mediation beyond that period, or
(d)
For other good cause.