Treatment

Fix broken pipes around Megaton is a minor Fallout 3 quest. When you ask "What needs to be done around here?", Walter refers to broken pipes around Megaton. He asks you to fix them. When asked why he can't fix them, he says he hasn't got the time.

The pipes require a Repair skill of 30 or better to fix.

When the pipes are fixed, Walter offers to buy scrap metal from you to maintain them. He will give you 10 bottlecaps per Metal Scrap item, or if you contribute them for free to him, you'll get positive karma.

Also you get 5 XP reward per scrap metal. This XP value can be very high if you contribute many scrap metals at once if you're well rested, and have the perk Swift Learner.

If your starting intelligence is at least 5, a simple way of completing this is to take Mentats, then equip the Vault 101 Utility Jumpsuit, which will give you the 30 repair skill required.