FROM RON
There are 18-ga-gillion articles out there about diets and eating properly, but no so many on the water you drink. Ask anyone about survival and the usual priorities you get are #1water and #2 food. So water is pretty essential to our survival and health, but who knows what kind of water we should drink?
I'm not the doctor on this blog, but I have been in water quality for over 30 years. Since I'm an engineer let's explore this topic logically.
First, anyone knows you're not supposed to put bad stuff in your body - we just don't all agree on what is bad. Looking at water, the usual "baddies" are: microbes, toxic metals, chlorine, endocrine disruptors (such as birth control pills), pharmaceuticals and fluoride. Some may have things like perchlorate or radiologicals, but they are very few. To know which of these usual bad guys you may have in your water, if you are on a public supply (ie, no well of your own) go to your water department's "Consumer Confidence Report". It should be online and it tells you where your water comes from, the treatment processes and final quality throughout the distribution system.
Addressing the baddies in order - microbes - if you are on a public supply, this is really rare. All public supplies disinfect and have to test for bacteria monthly, so probably no worries. If you have your own well, you should disinfect it every year and be OK. Toxic metals, again your supplier has to test for at least 13 of them and they should be in the CCR. If you are on a well, you should have these checked, it's not that uncommon. Chlorine, all public supplies have a disinfectant (usually chlorine) all the way to your tap. You can get rid of it with carbon filtration or reverse osmosis (RO). Endocrine disruptors, if your public supply is a surface water such as a lake or river, you probably have these and most treatment facilities do not remove them. If your supply is a well, you probably don't have them. Same for pharmaceuticals. Fluoride, most public supplies fluoridate. You can only remove it with RO. Wells rarely have high fluoride, but some areas need treatment even for groundwater.
I personally don't want any chlorine, or it's by-products in the water I drink. Same for fluoride. Now the question of how pure comes up! Treated, filtered, RO or distilled? (Bottled is another subject for the future). Distilled water is by far the most pure we can get as consumers. It has essentially all salts and dissolved materials removed. RO is next, but it depends on how it is done. Cities do RO at 400-600 psi pressure on the membranes and get 98-99% removal of dissolved salts and bigger molecules, but that is so expensive and that water so corrosive to pipes that they then usually blend it with the original at a ratio that will stay below the limits they have to meet. In other words, only a certain percentage of the water you see at the tap has gone through the RO and a certain percentage just had "conventional" treatment. My home RO unit has only 50-70 psi to work with, so it sends 80% of the water to the drain and purifies only 20% and that not as pure as a high pressure system.
Some will say you can't drink distilled water - it will suck the minerals out of your body. This is like taking a salt-water fish and dropping it into a freshwater lake. It will probably die because of the huge difference in osmotic pressure form the salt content. You would die too, if you drank only distilled water and didn't eat anything. However, if you take distilled water and mix it with a purified and trusted mineral source it is NOT a problem! Your body needs minerals and once "down the hatch" it doesn't care how it got them. I think this is where most of the disagreements come from.
If your food were decent and you got your 90 essential nutrients from it, there would be no problem, your body wouldn't know or care if it came in from the food or the water. The problem is that you can't get those essential nutrients from food anyway, so you have to supplement to get them. Our soils are demineralized and factory farming does not produce healthy food, neither is the meat decent because the regular meat is just fed depleted GMO corn-based feed.
So for me, I have a personal well, but I'm at the bottom of a hill and the people above me are on septic. I choose to drink only RO or distilled. If you are in a typical suburban or urban area, you might want to consider carbon as a minimum and RO if you can get it plumbed. Whole house carbon and RO for drinking is a good place to be. Whole house RO would be a ridiculous cost for little benefit.
I love to hear from people, as I do this for a living, although I don't sell any water filtration equipment. Let me know what your questions are and I can help you find a solution that works.