Wijesekera notes that there are numerous pilot programs around the globe that are testing in-home treatment technologies. But these can also be a burden on those who use them, so the hope would be to eventually have water piped much closer to home—if not in the actual premises.
Portable potable test
One of the reasons that the U.N. relies on improved sources as a measure of drinking water access rather than actual safety is that the latter is much more difficult to assess than counting wells and spigots. "It just isn't feasible to do bacterial tests," Wijesekera says.
"Over the last 20 years, there has not really been the capability in most developing countries to test water across the country," Gundry notes. For traditional, standard tests, water samples need to be kept below 4 degrees Celsius after collection until they are delivered to a lab where they can be cultured and examined under a microscope for microorganisms, such as Escherichia coli. To maintain that cool temperature, technicians need ice, which is often unobtainable in remote villages that do not have electricity. And labs are often ill-equipped and far away. "The barriers to getting samples in developing countries are fairly insurmountable," Gundry says.
Many groups are trying to tackle this problem. The challenge, Wijesekera says, is to make a test that is affordable, quick and can be used easily by people in the field who are not water quality experts.
Gundry and his colleagues have developed one possible solution. Called Aquatest, it is a compact, field-ready tool that provides a simple reading about the presence of E. coli within about 24 hours. They now have some 20,000 devices out in the field being used globally, and they are looking for a commercial partner to help increase production and distribution. But this and other devices will likely need much more evaluation before the U.N. and others can confidently mandate this sort of on-site water safety testing worldwide to truly get a bead on global access to safe water.
New focus on safety
Those at the U.N., WHO, UNICEF and other organizations are already starting to discuss how assessments might change after the 2015 MDG deadline has passed and the international community sets new targets. Gundry and others are hopeful that water safety will garner higher priority.
In the absence of better water safety data, Wijesekera notes that improved measurement of water sources is at least the best indicator that they currently have. And it underscores the progress that has been made in delivering protected water supplies to more people.
Nevertheless, whether there are 800 million or 1.8 billion people who lack safe water, the scourge of preventable deadly diarrheal and other waterborne diseases will continue to plague too many.
As Wijesekera points out, even the current WHO statistics "draw attention to the unfinished agenda" of improved water reaching another 800 million people and safe water reaching some one billion more. "It's not just enough to make progress on a broad front," he says. But many of these people are among the poorest 20 percent on the planet and can be "the hardest to reach—physically and politically," he notes.
And those who are falling into the gap, who have improved but unsafe water, are likely going to be difficult to help as well, especially without widespread, affordable water quality tests. Moving people from surface water collection to a new, protected well is much easier to see as progress than repairing a old well's housing. As the development community continues to focus on installing new pipes and drilling new wells for the large number of people with unimproved water sources, those whose infrastructures had been improved but are now failing often fail to get as much aid and attention.