Eventhough the second quote is from a different thread, I thought you were more of a person who kept to yourself, and turned your head as if it wasnt happening 
As far as this thread, I would really watch how to handle this situation. I myself would say something... Thats just me.
Two totaly different situations. There was no child involved in the first case. Dont make pull some quotes from you B-Xalted days

CPS should be the call you make AFTER you warn your brother that if he doesn't stop, you will call the authorities, and he still doesn't stop. After you offer to take your nephew out of the home so they can continue their ILLEGAL and HARMFUL activity, and he refuses, CPS is who you should call.
Yup. You can also try calling the narcs, but I dont know if that always works, I dont think we cant just go around acusing people of selling drugs, even if its true.
Whatever you do, you gotta do it fast. If they are slinging out of the house, then you dont know what might happen there. What if they get robbed and your nephew is there? You will feel guilty knowing that you coulda, woulda, shoulda done something sooner. So you gotta do something this week. preferebly Monday Morning.
Are you ready and able to take this kid into your home?
And the fact that the mother works for cps, is pretty crazy. You wouldnt beleive the things some of
us these people w/ connections get away with.
So before you go talk to the parents, ask God to guide your words and actions