Good paying drunk tenants

[Steven J.]

I've got some tenants in an apartment building that are a cause for concern. 4 separate tenants tend to imbibe quite often and enjoy each others presence some days and other days not so much. They also don't keep down the late night drinking but I've had a lack of other tenants reporting it to me. I hear all this from the cleaning lady we employ and its difficult to determine where the line of overly worried gossip and true lease infraction is taking place. 

Do you have any suggestions as to how to deal with good paying yet partying tenants? I know it happens but many of the tenants were trained poorly due to the previous manager. I've sent noise infractions to the units that other tenants have phoned me about (which is one as of late).