Broken Steel impressions.

[Ausfalcon]

Dodece said:

WARNING MINOR SPOILER, ACHIEVERS SHOULD PROBABLY READ.

The Holy Water quest costs you the Megaton water beggar

 

I did not interact with (or see) the Megaton water beggar at all during that quest.  The Wiki says it can happen another way which is what happened to me:

 

Megaton Alternatives

See point 2 & 3. You can find a note pinned to the door of your Megaton House, that leads you to the church. Alternatively you can speak to an NPC sitting next to the Brahmin at the bottom of the hill where you enter and he will give you the Holy Water Pamphlet. A NPC will also come up to you and complain about a cult stealing Megaton's water.

http://fallout.wikia.com/wiki/Holy_Water_(quest)