Two things I really believe in --- saving money and saving the planet, and it's even better when I can do something that accomplishes both at the same time. Rainwater harvesting is just such a thing. In the near future, rainwater harvesting will be as common as twelve-year-old girls carrying cell phones. Many countries already rely heavily on rainwater. Every building in these countries collects the rainwater from its roof and stores it for later use. However, America is just slightly slow to take action. There are many ways to harvest rainwater and most of them are easy and inexpensive. For example, use rain barrels to collect the water that would run off your roof. You'd be surprised at how fast a fifty-gallon barrel will be filled with free, usable water. New building construction offers some good ways to gather rainwater, and the cost of set-up is usually made up by reduced usage very quickly. Rainwater can be conveyed by roof pipes into underground containers, where a pump can draw water up as needed. The rainwater can even be treated to make it drinkable. If that rainwater were not collected, but allowed to run over your lawn , into the street and eventually to a storm water treatment facility, it would pick up all sorts of pollutants on its journey --- chemical compositions and agricultural poisons from the grass, motor oil, waste water and such from the roads, and who knows what else. That is to say, the shorter distance it covers the more drinkable it will be. Depending on where you live, the rainwater may be piped to a treatment plant or it may run in natural channels to allow nature to remove the pollutants. Either way, the treatment of rainwater is high priced. If you reduce the amount of rainwater run-off from your home or office, you reduce the need for treatment. Water is rapidly becoming one of our most precious resources and it is not as abundant as you may think. In the year 2015, the United States used generally 479 billion gallons of fresh water per day. It can be inferred from the passage that   _  .
it is easy to make rainwater drinkable the author calls on people to harvest rainwater many countries ignore to harvest rainwater it is easy to deal with the pollutants from rainwater