Are you using a pl? I noticed that sometimes even when using a pl if there's normally static on that freq. it comes through at the end of transmissions. It's actually interference being caused by something in the vacinity, in my case anyways. It comes and goes only on certain freq.s. Also get bleedover if theres a strong close by transmission on the same freq. different pl.
I tried doing an fcc license search for 155.490 in villas, nj but found nothing. If its a repeater your talking about perhaps the repeater receiver is not using reverse burst squelch. This is a feature designed to eliminate that burst of static. If its a base station on simplex then I'm not sure - could be various reasons why you are hearing that burst of static.
EDIT: I found it under a listing for "Lower Township" for call sign KBH341 and it is a repeater(FB2).