How community-driven water purification is overcoming scarcity & infrastructure deficits
In many places in both developed and developing economies, the supply of freshwater is under tremendous strain as the population grows. This is especially true in urban areas where the demand for resources is concentrated into a confined space. Despite progress, the United Nations (UN) estimates that 2.2 billion people still lack safely managed drinking water and 3 billion people lack basic handwashing facilities at home, depriving them of a vital way of combatting viruses, like the coronavirus. Water is scarce.
Digging deeper for water or relying on the river is not always an easy option, at least not without effective treatment, due to inherent high levels of fluorides and salts and increasing levels of nitrate and phosphorous pollutants from agricultural runoff. Building new centralized infrastructure or expanding capacities, if at all, is often only a long-term option.
Community-Driven Water Purification
To overcome this, many regions are installing water purification systems that have one key element: they are owned and run by the local community. One example is in Temba, north of Pretoria in the Republic of South Africa. Here, a new solar-powered borehole pumps raw water to a multi-stage purification system on the site of the Reneilwe Primary School. The ultrafiltration (UF) membrane and ultraviolet (UV) light system can supply up to 2,000 liters of healthy drinking water per hour, serving the local community and neighboring Itereleng Primary School by means of an on-site water kiosk.
DuPont paid for the borehole and solar plant, and donated the water treatment technology. Five “water champions” from the community have been trained in the operation and maintenance of the technology, which is highly automated but still requires a basic level of technical supervision.
The project was inaugurated on the 2021 World Water Day, March 22. Developed in partnership between the South African N.G.O. Kusini Water, the U.S. embassy and DuPont, it provides a lifeline for the health and well-being of the community. In South Africa, one out of three schools do not have access to safe water and clean sanitation, putting schoolchildren at risk of serious sickness from waterborne diseases and keeping pupils, especially girls, away from school.
The community of Temba is now one of more than 30 sites in the country that Kusini have helped in their mission to provide 5 million people with 5 million liters of safe water in five years. Putting the system in the hands of citizens not only ensure the system’s sustainability but also enables long-term impact on how people value and treat water. The topic and the technology has featured prominently in school lessons and the water kiosk is a focal point for the community.
Comparable community projects were completed in the last two years across the African continent. In drought-stricken Serdo, northeast of Addis Ababa, for example, abject disappointment followed the discovery of unsafe levels of fluoride and salt in the groundwater coming from their new borehole (one of dozens that had to subsequently be capped in the Great Rift Valley). Hope returned with the installation of 16 DuPont reverse osmosis (RO) elements. 5,000 liters of water per hour are now being purified, unleashing health and economic prosperity for 2,000 citizens. Kenyans suffer from a similar problem, with an estimated 20 million nationals afflicted with teeth and bone fluorosis.
The Little Sisters of St. Francis, who run the Kasarani hospital northeast of Nairobi, took on the problem for 6,000 people in their community not least at the hospital, and oversaw the installation of a combined UF and nanofiltration purification system that reduces fluoride to a safe 1.5 ppm. The Sisters pass on the benefits of this pure water to the local community, as well, selling it at a price of $0.4 for 20 liters compared to $20 citizens were typically paying in the supermarket for the same amount.
What is a Circular Economy Approach?
This circular economy approach is not only limited to Africa. Desalitech Closed-Circuit Reverse Osmosis (CCRO) technology recovers up to 95% of water from unconventional sources, making reuse on-site a viable alternative to a lineal supply and discharge of water. So, for example, in downtown San Francisco a CCRO solution is at the heart of solving one headache for the subway metro station while supplying water to the neighborhood power plant.
Clearway Energy (previously NRG), who runs the steam generation plant, was once one of San Francisco’s biggest freshwater consumers, pumping it in from the surrounding water-scarce region. The CCRO enabled them to utilize the polluted leaching runoff water, also taking the burden of disposal off the transportation company (SFPUC). The challenges were many — the need for high recovery given the limited and costly brine disposal alternatives; the need to purify source water that would constantly alternate between the runoff stream, municipal supply, groundwater and rainwater; and the need for total reliability and fully autonomous operation given the criticality of the steam generation and the lack of water expertise at the plant.
The project cost $3.75 million, including runoff water filtration, pumping, piping, a new well and the UF-RO system. The result is an annual savings of $1.8 million and 50 million gallons of potable water and a new “sustainable steam” product for the plant.
As even the most advanced water treatment technology becomes increasingly automated and reliable, the opportunities for communities to install and run their own systems are gaining momentum, helping connect more people and possibilities to flow.