You could send a certified letter to the builder of the new site, noting that his proposed site will create potential frequency conflicts with an already established site, and due to that, there will be no guarantee that at any time his "desired" frequency will be safe to use. Note all the potential hzards he is planning to create for yor club and himself. Send a copy to the guy's attourney and insurance carrier (if you can locate them...) and they will "draw and quarter" him if he proceeds.

If his insurance carrier doesn't immediately send a notice that they WON'T cover him if he proceeds... they are stupid.