It is still a problem for many people in the world to have safe water to drink. Some people hold that bottled water is a more convenient product than tap water when you need a quick drink; 41 , few may wonder where the former is made and why it costs so much. In fact, tap water isn't a universal luxury. It's 42 that more than 800 million people around the world don't have safe drinking water, and even in the US, cities had to use bottled water 43 tap water. The tap water had aging facilities or toxic chemicals in the water supply. On the other hand, bottled water has a huge environmental impact. It usually 44 a lake, spring, or underground aquifer, and on average, 45 need 3 liters of water to make one liter of bottled water. To make plastic bottles, they need billions of gallons of oil every year and 2,000 times more energy than tap water needs.