Here is a quote directly from the CDC. I'll put in bold what you should pay attention to. "You cannot get infected from drinking water contaminated with Naegleria. You can only be infected when contaminated water goes up into your nose." If you're worried about getting it, take standard precautionary methods. For instance, don't go swimming in lakes, rivers, and other natural bodies of fresh water. If you have a pool, make sure to put the standard chemicals in there at necessary intervals, and so on. If all of this is still bothering you then wear some sort of facial protection such as just a simple surgical mask when sweeping or doing other work outside that could kick up dirt and soil, and wear one of those nose pincher things when swimming. Also, just keep in mind that from a statistical standpoint there are a few things that you're more likely to do than contract this. These include: winning the top honor as a professional athlete (World Series, NBA finals, SuperBowl, World Cup, etc), win one of the largest lottery amounts that has ever been won, or get struck my lightning (multiple times) just to name a few.