Water has sometimes been called “the new oil” due to its centrality to the sustainability of human communities. Like oil, water is also now viewed through the prism of scarcity. While it is still a renewable resource (unlike any fossil fuel), its availability cannot be taken for granted:
- The United Nations estimates that 1.7 billion people live in river basins in which water supply recharge cannot keep pace with use.
- Another 700 million lack access to clean water.
- Overall, water scarcity affects roughly 40 percent of the world’s inhabitants.
Scarcity has many drivers, starting with: freshwater only accounting for 3 percent of all water on earth. But there are other causes more directly under human control, such as pollution, overuse in agriculture and rapid economic development to support population growth.
Environmental engineers have a vital roles in minimizing stress of water resources and ensuring consistent access to them. Let’s take a look at what they can do to reduce the worldwide incidence of water scarcity:
Rainwater harvesting systems
In many parts of the world, water scarcity is the product of inadequate infrastructure instead of insufficient precipitation. In fact, according to visualizations from the Massachusetts Institute of Technology, some of the world’s relatively water-rich regions, such as portions of Sub-Saharan Africa, have extremely low access, while areas with high natural water stress (like the Great Plains in North America and most of Europe) have few availability issues.
One reason for this sharp divide is differing levels of investment in rainwater harvesting, which can capture precipitation and store it for later consumption. In the Fars Province of Iran, more than 808 million cubic meters of water across 1.7 million hectares were stored by such infrastructure after some wet weather in 2017; however, an even larger amount was wasted since the existing systems were not large enough to capture everything.
For hot and dry nations such as Iran, rainwater harvesting is a multifaceted solution to problems of water scarcity:
- It reduces the stress on main water supplies.
- It lessens runoff and contamination after rainfall.
- It provides usable water for the nonpotable uses (e.g., agriculture) that constitute the bulk of all water usage worldwide.
At the same time, rainwater harvesting is not enough for residents of countries with exceptional water scarcity. Treatment and recycling are also necessary for sustaining water consumption in the context of heavy utilization, minimal regional water flow, insufficient precipitation and pollution.
Water recycling plants
When there is not enough rain or snow to reliably recharge water supplies, recycling of wastewater becomes essential. In Israel, a quarter of all demand for water is met with treated sewage. This reuse is combined with widespread desalination, which was implemented in multiple plants on the Mediterranean Sea in the 1990s following a particularly severe drought, to ensure consistent access to water across the country.
Recycling is a highly efficient solution for increasing the amount of water available for irrigation. Crops that do not come into direct contact with treated water, such as almonds, are prime beneficiaries of recycling, as they are less exposed to the trace elements contained in even the highest quality recycled water.
An Israeli firm contributed to the design of the largest desalination plant in the U.S., a facility in San Diego that was built during the height of the California droughts in the mid-2010s. The state’s water supplies came under scrutiny in this period: In a typical year, approximately 80 percent of its developed water is used for agriculture, according to The New York Times. Like Israel, California is home to many especially water-intensive crops, including almonds and walnuts, as well as numerous livestock.
While it is central throughout the Middle East and in small sovereignties such as Singapore, recycling is still underutilized overall and as such retains enormous potential to improve water access:
- A 2012 report from the National Academy of Sciences estimated that 12 billion gallons of municipal wastewater were discharged each day to oceans and estuaries in the U.S.
- Recycling all these discharges would increase the nation’s public supplies by 27 percent and supplement water systems for irrigation and human consumption.
- Environmental engineering plays an important role in quality assurance processes, since it can help in setting up artificial barriers to screen out microbial contaminants, in addition to existing natural buffers such as intervening lakes, aquifers and wetlands.
With the pressure climate change will put on water supplies, greater utilization of recycling is likely inevitable in both potable and nonpotable use.
Air quality improvements
The World Bank has projected that global precipitation will ultimately increase 2 percent from the 20th to the 21st century. That sounds like good news, but it probably isn’t. Precipitation intensity (i.e., the amount of it that comes from storms) is set to surge 7 percent over the same period, due in large part to increased carbon dioxide emissions.
More frequent storms actually destabilize, rather than reinforce, water supplies. They are typically preceded by droughts that dry out the soil, resulting in extensive erosion once the precipitation is finally distributed. This erosion diminishes water supply quality by increasing the volume of contaminants in it.
Air quality engineers can address the issue of volatile precipitation. Collaboration with industrial organizations can lead to reduced emissions, tighter regulatory compliance and potentially buy-in to long-term solutions like carbon capture. Less carbon dioxide in the atmosphere should stabilize precipitation patterns while improving quality for all use cases.
Explore environmental engineering to further the water conservation cause
A master of science in engineering, with a specialization track in environmental engineering, puts you on the path to make a difference in the worldwide water conservation efforts. You can conveniently earn your degree online at the University of California, Riverside and pick up the conceptual and technical knowledge you need to excel in your work. Learn more about courses, career options and program distinctions on the environmental engineering page.
Earth Magazine, Drinking Toilet Water: The Science (And Psychology) of Wastewater Recycling
The New York Times, California Announces Restrictions on Water Use By Farmers
The Mercury Times, Nation’s largest ocean desalination plant goes up near San Diego; Future of the California coast?
Financial Tribune, Vast Amount of Rainfall Wasted in Fars Province
City of Chicago Department of Environment, Rainwater Cisterns
MIT, Engineering Solutions
Springer, Water Conservation Science and Engineering
WWF, WATER SCARCITY
NPR, Israel Bringing Its Years Of Desalination Experience To California
MIT, Carbon Capture and Storage
The National Academies of Sciences, Engineering, Medicine