Is bottled water better than tap?

Description:
This is for an aqautic pollution and toxicology class. It"s a master"s level course.
The instructor has said figures and charts can be included but to keep these to a minimum- i would say no more than three, and not taking up much room. The paper is on the topic of whther or not bottled water is safer than tap water. I would discuss the health/nutrition aspects of each and also the environmental impact of bottled water, and the cost, etc.. There aren"t really guidelines for what exactly has to be said in the paper those were just some ideas of what I would have included.