What city has the cleanest (best) drinking water?
There's a list that publishes the best tap water in the USA. Winner's 2007: Municipal Water Gold: Montpelier, Ohio Silver: Clearbrook, BC, Canada Bronze: Elkford, BC, Canada 4th: Campbell River, BC, Canada 5th: Metropolitan Water District of Southern California
Is dirty water bad for plants?
Depends what the "dirty" part is. if it's just dirt, no, it won't hurt. Plant GROW in dirt. They need dirt. If there are toxins in the water, or herbicides, then yes, those could hurt them. If you are talking about grey water from your house, then if you use biodegradable, organic soaps and such, it should be perfectly fine.
Would boiling tap water clean it?
Water gets it taste from other minerals in the water. Boiling would not remove those minerals. However if a chemical is added to treat the water such as Chlorine then boiling will help remove the smell. I assume you live in a larger city. Normally water is processed very fast and has less time to be treated properly. Boiling for 10 minutes will do the same as 20 minutes or more. Also boiling will not kill all bacteria and virus's like other people have said. It will help but the only way to kill all bacteria and virus's would be to run the water through an autoclave which would turn the water into steam. Several stages of treatment and chemicals such as chlorine is the only other way to remove all bacteria and virus's (99.99%). A filter is the only other option and it may help or not with taste and smell.
Can rice water be beneficial for plants?
Just like potato water, rice water also contains valuable nutrients for houseplants. Using it is also a wonderful way to conserve water and a great way to take some of the worry out of over-fertilizing. The starches from leftover rice water will help encourage beneficial soil bacteria, while the vitamins and minerals will add small amounts of NPK (nitrogen, phosphorus and potassium) to the soil. One thing to keep in mind when using water from cooking on your houseplants is to make sure the water has cooled to room temperature before you use it. It's also best to avoid using water that you have added salt to. Just about any clear or light-colored water that is left over after cooking is probably okay to use as long as it doesn't contain salts. This includes using water from cooking hard-boiled eggs, pasta and vegetables. If you have a freshwater fish aquarium, save some water for your houseplants every time you clean it.
Why is it important to keep our usable supply of fresh water clean?
So we can drink it. If our usable supply of fresh water is not clean, what will we drink? Can't drink sea water/salt water. It dehydrates. It's possible to desalinate sea water (remove the salt), but the process is extremely expensive, and I believe it's very energy-intensive, and if we get to the point that we're out of clean fresh water, we'll probably be in the throes of a serious energy crisis as well. Plants and animals need clean water, too. If our fresh water is contaminated with, say, toxins, it could kill the plants and animals we use to make tasty and nutritious dinners. Or maybe it won't kill them, but the chemicals build up in their bodies, and when we eat them, we get the chemicals. This is already happening. So many people flush prescription meds down the toilet that certain fish species are getting a serious dose of things like antidepressants. Ahhhh, happy fish. Not so good when you're talking about something like mercury, though, which we tend to find in tuna (although they're a salt-water fish, but same principle). That's why pregnant women are told to limit their intake of tuna.