Can someone please tell me how to get the sewage golem to talk to me. It says that Sewage Golem appears busy, and dialog cannot be started.

have you already talked to him and got him to do his job?

If not and you need to carry on just get imoen to pickpocket him a few times, and you'll lift his key and be able to carry on, if you want the XP for doing his activation "quest" just restart the game since it's so early anyway.

You could have Immy pickpocket it if you like, but this sounds like a patching problem. Are you fully patched?

This is a common bug if you are running Baldurs Gate 2 on a Windows XP. The best solution if this is the case is to copy your save files, then reinstall the game. Immediately put back your saves and fully patch your game. This should make it work. Even if he responds, random characters throughout the game will have this message appear when you try to start dialogue.
-Brainless One

I have no idea how to fix this problem, but I just wanted to tell you that I love your username, Dalamar Stormcrow.

You've combined two of my favorite fantasy wizards' names into one! Why no "Sparrowhawk" middle name? ;)

<span style="color: lightblue">The official patch fixes this problem. No need to reinstall, just get the patch and install it.

Yup, always, always fully patch your game. If you buy a game look for a patch, simple. Anyways if you just want to bypass him you can as it has been said pickpocket him for the key, IIRC he doesn't go hostile on you, ever.

Dalamar i made up myself. And Stromcrow is Gandalf's surname. What other wizard?

I had to reinstall mine. I tried patching it after playing some and stuff, and the bug kept happening. Only after I removed my saves and reinstalled, then patched did it work. I dont know why, but it was a hassle.
-Brainless One

Dalamar is the name of Raistlin's apprentice, a high level elven black robed mage.

Sparrowhawk is the name I was referring to as the "why no ..." name. He's my other favorite wizard, from "The Wizard of Earthsea" novels by Ursula LeGuin. Awesome books, btw (and very few fantasy books have a wizard as the main character).