Let's say you live in a rural village of 100 people. Nearby, there is a stream. Unfortunately, your and your neighbors' outhouses empty into it. Whenever you need potable water, you must walk six miles (10 kilometers) to a well and lug a small supply of water home in jugs or you drink the stream water and take your chances. How would the Slingshot help you and your community?
In one day of running stream water through the Slingshot, you'd be able to make 264.2 gallons (1,000 liters) of clean water [source: Schonfeld]. Since each villager uses about 5.3 gallons (20 liters) of water a day for drinking, cooking, and bathing, which is typical in a developing village, one Slingshot could supply enough water to support the needs of half of the village [source: United Nations]. This sounds great -- but could the village afford it?
Assuming the community has electricity to run the Slingshot, it would need $1,000 to $2,000 to buy one [source: Schonfeld]. Every villager could chip in $10 to $20, but that's more than a week's salary in plenty of places [source: United Nations]. More realistically, some community members might get a loan, buy the Slingshot and then sell clean water to the rest of the village at an affordable price (perhaps three cents per gallon or one cent per liter) until the machine is paid for [source: Schonfeld].
OK, so you know what it will cost financially, but what else is there to consider? What are the pros and cons of using the Slingshot?
One convenience of the Slingshot system is that the village would not need an expert to run the purifier. The instructions are super simple -- you stick the hose in dirty water and press a button. This simplicity makes the system safe to operate with little room for human error or mishaps. Another plus is that the water should have no chemical aftertaste thanks to the distillation process.
While operating the system requires the simple push of a button, you would still need to get water to the purifier. Typically, that means either carrying dirty water to the purifier or putting the purifier near the dirty water supply. The purifier is too heavy for one person to carry, so moving it would require a little bit of man- (or woman-) power. And finally, the machine's moving parts could eventually break and require servicing or replacing, which would cost money.
Read on to find out what's on the horizon for the Slingshot.