Clean water & sanitation
According to Rotary Australia's June 2019 magazine, more than 80% of human wastewater is discharged into rivers and the ocean without any pollution control. Besides the adverse environmental impacts for wildlife & crops in and around rivers & coastlines, the consequences of poor sanitation for people are shocking. Even in 2015, 4.5 billion people (over half the global population) lacked safely-managed sanitation services and about a billion people (13% of the global population) had inadequate access to safe drinking water whilst 2.7 billion find water scarce for at least one month of the year. Still in 2019, about a billion people defecate in the open every day as they have no alternative, and - largely because of inadequate servicing & maintenance - another 2.4 billion people (including many indigenous Australians) live with substandard sanitation. Half of people in hospital beds in sub-Saharan Africa are there because of diseases directly related to poor sanitation, and every year around 14,500 children under five in East Indonesia die from diarrhoea - contributing to the 1.1 million annual global child deaths (plus 700,000 adults), including 500,000 infants, and US$233 billion p.a. in global costs caused by unsafe water, sanitation & hygiene.
In 80% of the households around the world without a direct water supply, women & girls are responsible for water collection, and this obligation, along with inadequate sanitary facilities, are major reasons why 20% of girls in India drop out of school when they reach puberty. Moreover, with no toilet at home, up to half of reported rapes in some Indian states happen to females seeking a secluded place to go outside of daylight hours.
Improvements are being made (including through help from Rotary projects such as "Operation Toilets" - see this TED talk); for example, in 2014 only 40% of Indian households had a toilet and in 2016, half of India's rural population practiced open defecation, but over the 5 years to 2019 the Indian government provided toilets for 90% of the 100 million homes that lacked one, reducing deaths from open defecation by two thirds.
However, there are still millions of people in the country without access to a usable toilet and many that have been built are not properly connected or maintained and being used. Less than 5% of India's towns & cities have sewage treatment plants (& only 30% of sewage is treated in big cities), whilst in 2018 nearly a quarter of school toilets were unusable and in four northern Indian states almost a quarter of people in households with toilets still defecated in the open. This points to a need for self-contained & affordable, low-water-use toilets that don't require a sewage connection or any other significant maintenance services, such as this "Cinderella" incineration toilet, which simply converts human waste into a small pile of sterile ashes that can be used as fertiliser (although it is currently rather expensive). A variety of alternative new toilet technologies are also being pursued by the Bill & Melinda Gates Foundation.
Globally about 2 billion people are still at immediate risk of being without water, and by 2050 this could rise to 5 billion, along with about a quarter of the world's population also potentially becoming exposed to chronic and recurring freshwater shortages.
Does it make you think about what we take for granted when we're deciding how to spend our money in the West? Frankly I can't think of a higher priority for global society to invest our limited resources in, so that's something I've been working on, combined with some ideas about solar energy, affordable, modular housing & stakeholder finance.
Urban water recycling?
This is a brief note on some thoughts I started that didn't progress far. I wondered whether rainwater collection, conservation & recycling systems could sufficiently reduce home water demand to make it viable to have substantially lower capacity (and cost) water reticulation supply systems (smaller pipes & pumps etc.), similar to my ideas for a transformed, distributed electricity grid using residential solar and low-power telecom wires. The obstacle to the viability of such things though is the large economies-of-scale resulting from the fixed costs of providing any water services at all, especially sewage systems, which makes me doubtful that recycling systems requiring a second set of pipes (beyond the home) for "grey" recycled water can be cost-effective. Also I'm not sure there is any intrinsic environmental advantage from water recycling, because ultimately all water is recycled - it's just a matter of how and where it's cleaned, and at what cost. "Closed-loop" recycling would never be a safe health option, so all recycling systems have to at least partially clean and discharge some waste water, even if this mixes with fresh water that is then pumped back into the water supply system. So taking Sydney as an example, you could clean waste water from western Sydney and discharge it into the Parramatta river, then source & clean water for Eastern Sydney from the same river downstream or from Sydney Harbour (into which this river flows), or alternatively you could pump western Sydney's waste water further east and out to sea (requiring a lesser standard of cleaning) and source water for Eastern Sydney from the sea using more expensive desalination technology. If environmental controls on inputs (like renewable energy) and waste discharges are sufficient, then the best choice really just comes down to costs. I suspect then that as long as you have a sewage connection to a premise it's very hard to significantly reduce the costs of urban water services through recycling (but I'd need to learn a lot more about the design & costs of current systems to reach a firm conclusion).