what exactly is in our water ???

Depending on where you go to depends on what you get told on what is in you water. Most bottled water companies tend to state similar values around:

Typical Analysis (mg/l)

Calcium	90
Magnesium	2.4
Sodium	15
Potassium	1.3
Iron	<1
Bicarbonate	213
Chloride	33
Sulphate	18
Fluoride	<1
Total dissolved solids at 260°C	374

ref http://images.google.co.uk/imgres?imgurl=http://www.kingsdownwater.co.uk/images/our_water.jpg&imgrefurl=http://www.kingsdownwater.co.uk/our_water.html&usg=__DMJQm_QVvo0i_tt2qYc50pnMa1w=&h=485&w=360&sz=40&hl=en&start=2&um=1&tbnid=qPbpXatFTwmk5M:&tbnh=129&tbnw=96&prev=/images%3Fq%3Dwhat%2Bis%2Bin%2Bour%2Bwater%26um%3D1%26hl%3Den%26lr%3D%26sa%3DG

However it has become apparent that you can add pretty much anything you like water as many other companies have shown such as Vitamin water:

What's in Vitaminwater?Nutrition Facts:

• Calories: 50
• Total fat: 0g
• Sodium: 0mg
• Potassium: 60mg
• Total carbohydrates: 13g
• Sugar: 13g
• Protein: 0g
• Vitamin C: 40%, Vitamin B3: 20%, Vitamin B6: 20%, Vitamin B12: 20%, Vitamin B5: 20%
• Potassium: 150mg per bottle

Ingredients: vapor distilled/deionized water, crystalline fructose, citric acid, vegetable juice (color), natural flavor, ascorbic acid (vitamin C), vitamin E acetate, magnesium lactate (elecrolyte), calcium lactate (electrolyte), zinc picolinate, monopotassium phosphate (electrolyte), niacin (B3), pantothenic acid (B5), pyridoxine hydrochloride (B6), cyanocobalamine (B12)

One interesting thing to notice is the amount of sugar in what is supposedly good for you water! This is discussed further on this website as the benefits of additive in water are brought into question.

http://recipes.howstuffworks.com/vitaminwater2.htm