A Conversation With An Inquisitive 5-Year-Old

Today while we were eating lunch, Nicole asked me the following question, "Mommy, how do they make the water in the mountains clean?"
This is a typical question to hear from her. Every day I hear a question like, How does the electricity make the light bulb work, or how were the mountains made, or what are clouds made of, or why does our heart beat faster when we're running. I feel like I need to buy an encyclopedia and start looking things up so I can get my answers correct.
Today I was busy eating my own lunch and not super eager to delve into the specifics of the water purification process, so I answered, "Hmm... good question... I don't know."
I saw her puzzling that one over for a bit while she finished off her cheese & Crackers. A few minutes later she said, "I think I know how they do it. They get a net with tiny, tiny holes and they put water through it and then all of the dirt is too big to fit through the holes so it stays behind and the water is clean."
Impressed by her quick conclusion, I answered, "Yes. That's exactly right. That's called a filter. They run the water through a filter and gets all the dirt out."
I could see that she wasn't satisfied quite yet. A minute or two later she asked, "But what about all the germs? They're smaller than the water so they would go right through the filter too."
"Yes," I replied, "Germs are too small to filter out so they have to use chemicals to get rid of the germs."
"How do chemicals get rid of germs? Do they chase them away?"
"No. Not exactly. They use chemicals that are poisonous to the germs and it kills them. They don't use enough to hurt us, but it kills the germs."
Then I saw the funniest, most horrified look on her face. "You mean that every time we drink water we're drinking dead germs? That is Dis-gus-ting!"
Nicole's so fun because she always keeps me guessing. Pretty soon I'm going to be asking her the questions, and I'll bet you she knows the answer.