East Hampton Town Supervisor Larry Cantwell and the Town Hall legal team are on the right track in looking at how to amend town law to head off further conversions of hotels and motels into hybrids that include nightclubs and accommodations. According to the town, there are some 70 hotels here whose owners might someday seek to expand into the lucrative bar trade, which could create traffic, crowds, noise, litter, and, in some cases, water pollution problems, which have already been the result.