The United Nations is sounding an alarm over polluted water supplies. According to the UN, more people die each year from polluted water than from all forms of violence, including war. In fact, 3.7 percent of all deaths can be attributed to water-related diseases and over half the world’s hospital beds are occupied by people suffering from a water-borne disease. These are staggering statistics given that water is typically touted as a means of reducing disease.
In its latest report timed to coincide with World Water Day, Sick Water, the UN points out that an estimated 2 billion tons of wastewater are discharged daily; that waste can spread disease and damage the environment. Undersecretary General, Achim Steiner, upon releasing the report said that, “if we are not able to manage our waste, then that means more people dying from waterborne diseases.â€
The UN report encourages planners to think of wastewater as a resource. When managed well and when effective sewage treatment systems are in place, a wastewater stream from an urban area can be an enabling resource for food production. In Figure 1, below, the tradeoff can be easily understood. With proper wastewater treatment, food production can increase and nutrients are returned to the soil. In the absence of that critical step, waterborne disease risk increases and contaminants enter the soil, eventually finding their way the food supply. The UN hopes to illustrate that sewage treatment is not a luxury or a cost without a tangible benefit. By linking a treated waste stream to higher quality food production, the UN is encouraging leaders to look at the “bigger picture†when investing in infrastructure.
Figure 1 – Wastewater in urban agriculture – reprinted from Sick Water, a UN report
While wastewater can be a resource enabling improved food production, a significant amount of wastewater is still generated by food production; additionally, water is needed to produce the food, as well. Depending on the crop, the water used (which then must be reprocessed in some way) can be very little or quite large. In the graphic below, this wide variation in water use can be witnessed; not surprisingly meat production requires significant resources. What is somewhat alarming, however, is that rice – a staple crop for billions and the foodstuff of choice for relief agencies is a heavy consumer of water. This suggests that shifting diets towards potatoes and corn, both native crops of the Americas, would benefit the global community.
Figure 2 – Water use in food production – reprinted from Sick Water, a UN report.
Beyond food production, the report also seeks to move toward a more nuanced understanding of wastewater issues. Its authors discuss not only waterborne illness and death in the developing world but the impact of oceanic and river “dead zones†in the developed world. The US, Canada and Europe all have regions where eutrophication has occurred. Eutrophication is a process where chemical nutrients such as nitrogen and phosphorus have increased and the oxygen level in the water has dropped below the level where aquatic life can be supported. This growing problem means that these industrialized nations can no longer take their ocean-based food resources for granted.
The report is hopeful in many ways, showing marked increases in sanitation and waste treatment in developing nations. At the same time, the report strikes a balance between these improvements and the challenges that still face our world. With a pat on the back for the gains we have made, there is a continuing call to action to make our future a more livable one.