The wastewater solution

As worldwide water supplies run dangerously low, nations are looking to ingenious solutions to stem the possibility of a disastrous global drought

“Available on tap” is an idiom used when referring to free-flowing goods available in unlimited quantities. Water used to be considered such a thing, but this is not necessarily the case anymore as it is becoming a commodity that is quite literally running out. Experts agree climate change will most definitely bring about dramatic changes in water levels – in some regions they will increase, while the supply in mid-latitudes are expected to suffer a hefty reduction. Putting further strains on the dwindling resources, other factors come in to play too, such as rapidly increasing populations and the urbanisation and industrialisation of emerging economies. The problem is further spurred by the public’s default tendency to waste water – allegedly, less than 10 percent of drinkable water is used for cooking, drinking, showering or washing dishes.

The worry is that plants and crops irrigated with recycled water may absorb harmful contaminants and pass them on to humans

So what is the solution? Due to the lack of natural water sources, governments across the globe have had to resort to alternative means of providing their residents and businesses with water. The idea of recycled wastewater might seem unappealing to many, but it is a solution that must be embraced in order to provide enough for all uses. Reclaimed water offers a well-needed secondary source to be used across a wide platform of industries and to aid private, everyday matters. Uses include irrigation, dust control, fire suppression and even drinking. The US is certainly not a novice in the sphere of reclaimed water. Some states have practised and honed the art of water recycling for decades. Los Angeles sanitation districts have safely offered up recycled wastewater for irrigation purposes since 1929, often to refresh the area’s numerous parks and golf courses. Since reclaimed water forms such a big part of American society, the country has established quite a sophisticated system of legal guidance, namely the ‘Clean Water Act’ (CWA). This is the primary federal law in the US governing water pollution, and it’s established the goals of eliminating the release of high amounts of toxic substances into water, eliminating water pollution and ensuring that surface waters would meet necessary stringent standards.

However, CWA does not apply to groundwater contamination; this protection provision is included in the Safe Drinking Water Act, Resource Conservation and Recovery Act, and the Superfund Act.

Concerns and misconceptions  
Like any other form of mildly unorthodox organic development – such as GM food for example – the idea of recycled wastewater is a hotly debated subject and opinions are widely divided. While there are avid supporters, many have turned their noses up at the concept.

A case that hit the headlines at the beginning of the year involved the enormous backlash against a plan to use artificial snow derived from reclaimed wastewater to create a winter wonderland at a ski resort in Arizona, US.

Akin to the case that has unfolded around the artificial ski slopes of Arizona, the opposing camp’s main concerns relate to health issues. The worry is that plants, crops and flowerbeds irrigated with recycled water may absorb harmful contaminants and pass them on to humans. Even though modern treatment apparatuses are designed to effectively eradicate any potential residue of contamination, some have argued that there is still a slight risk that the filter system will fail, or that some traces of sinister pathogens and chemicals may be impossible to eradicate completely. Concerns are in part justified, as sewage water contains a catalogue of unpalatable ingredients including faecal matter, bacteria, viruses, pesticides, fertilizers, hormones, and industrial waste. And since water used for irrigation is forced through sprinklers and nozzles, tiny droplets can travel in the air and accidentally be inhaled by humans.

Recycled water has been subject to a number of filtration systems to remove most of the harmful chemicals and pathogens

Much to the relief of parents of school children, who might be exposed to reclaimed water due to frequenting playgrounds and parklands, a study called “Irrigation of Parks, Playgrounds, and Schoolyards with Reclaimed Water” established that there had been no reported cases of illness or disease from microbial pathogens or chemicals. The report, which was carried out in 2005, concluded that the use of reclaimed water does not pose a greater risk than if potable water were used.

Further positive findings were revealed in 2009, when a study found that the water quality difference between recycled water, surface water, and groundwater showed an almost identical set of constituents of the 244 varieties they were tested for. When detected, most constituents merely appeared in parts per billion quantities, or even parts per trillion ranges. Commonly occurring ingredients included traces of the insect repellent DEET and caffeine. Significantly, these remnants were found in all water types. Meanwhile, Triclosan – an agent found in anti-bacterial soap and toothpaste – did occur in every sample, with slightly higher levels in recycled water than in surface and ground water. The most significant finding, however, was that reclaimed water contained disinfection by-products since it had been treated.

The differences between recycled and ‘natural’ forms of water appear to be extremely minor indeed. A common misconception is that all recycled wastewater is inherently dirty and contaminated, despite having been cleansed thoroughly. In reality, recycled water has been subject to a number of filtration systems to remove most, if not all of the harmful chemicals and pathogens. However, in recycled water which is intended to be used for irrigation, certain contaminants, such as nitrogen, potassium and phosphorus are allowed to remain at higher levels as they actually serve as nutrients to plants and crops.

Refining the source  
The benefits of using recycled water are obvious – the earth’s supply will only last for so long and it shouldn’t be assumed that it will be topped up automatically to fulfil the need of an ever-growing population. While the cost of recycled water varies from country to country, and can be costly to produce, it is often more affordable to consumers than the natural variety, which should serve as a further incentive to embrace reclaimed water – no matter from where it has been sourced. With wider use of reclaimed water, individuals and businesses can save money using water to irrigate lawns, wash cars and clean work areas. The environmental advantages are equally significant, as wastewater that has been filtered and purified keeps rivers, lakes and oceans clean. These days, all wastewater must be treated before it can be either used anew or discharged into larger bodies of water so as to preserve the environment.

Water is always treated according to a level that corresponds with its intended use, be it irrigation, industrial cooling or for drinking or cooking. Whatever the purpose, modern filtration systems are so sophisticated that they can remove most contaminants and thus allow for recycling and water being reused over and over again. The first stage of the process sees the wastewater being sent to treatment plants in order to remove large material. Once it has been filtered out, the water is then oxygenated to make it safe for human consumption.

Siemens is a respected firm within the recycled water arena, and the company is working closely with several governments to provide high-tech solutions with which to create water as clean and crisp as possible. At a Siemens plant in Singapore, the pores of the fibre membranes used to clean pre-treated waste water are as much as 2000 times thinner than a sheet of paper, which means that the removal of any traces of dirt, oil and dirt is far more effective.

Tapped up
While some countries top up their diminishing supply of water by using recycled water exclusively to irrigate lawns and farmlands, other nations have taken it a step further, using it for human consumption. While this method is employed largely on a household level, it is especially important aboard human spacecrafts. NASA famously developed a human waste reclamation bioreactor in 1998 designed for use in the International Space Station and a potential manned flight to Mars.

Controversial a solution as it might seem, recycled wastewater born again for the purpose of quenching the thirst of humans – be they astronauts, bus drivers, or accountants – is a necessity in parts of the world as water scarcity is a growing issue. The US is one region that is prone to water shortages, particularly so in states that enjoy intense heat such as California and Arizona. Perhaps given the US’s strong heritage in wastewater, its consumption is already common practice, although most residents aren’t necessarily aware they’re actually drinking water that is not pure as spring water. Due to its association with toilets, sinks and washing machines, the liquid has been crudely dubbed “toilet on tap”. But despite the fact that the water passing the lips of many Americans was once spiked with unpalatable residue such as urine, bath oil and lime scale remover, the National Research Council (NRC) asserts that recycled water could actually be better for human health than fresh water. Indeed, after any dubious materials and chemicals have been filtered out, wastewater is nothing but “used water” according to the US Geological Survey.

Only wastewater that has been thoroughly treated – and repeatedly so – gets back into the system to potentially be consumed. In spite of this reassuring fact, critics have pointed out that the last industry-wide study on wastewater used for drinking was conducted as far back as the 1980s, and opinion is still divided whether or not it is suitable as drinking water. While the NRC ruled waste water unsafe to drink at the end of the 1990s, they have now deemed it a perfectly viable option, and a “drought proof” alternative that won’t put the public at risk.

The authority of Singapore and its refinery partner Siemens have dubbed their carefully distilled product “Newater”

US citizens are not the only ones to sip “toilet on tap”. Residents in Queensland, Australia were in for an unpleasant surprise when the government revealed that locals had no choice but to start drinking water containing recycled sewage as a result of the severe drought of 2007. The then Prime Minister, John Howard, stepped forward as an avid advocate of recycled water, and one can understand why he would be in favour of the industry, as he declared that » water security was to be the biggest challenge to face Australia.

Queensland state Premier Peter Beattie told ABC radio in 2007: “These are ugly decisions, but you either drink water or you die. There’s no choice. It’s liquid gold, it’s a matter of life and death.”

Modernising methods
Singaporean citizens aren’t strangers to the idea of drinking reclaimed water either; in fact, the burgeoning economy relies heavily on recycled wastewater as well as the desalination of sea water. It is not surprising that these methods are being embraced; the destination doesn’t boast natural fresh water resources, and its rising population and growing prosperity has seen the demand for drinking water surge markedly.

To boost its own resources, water has been imported from neighbouring Malaysia for decades. While Malaysia proved a reliable provider, its commitment didn’t come without a price. To gain a political upper hand and pressure its water-deprived neighbour, Malaysia has been known to issue cruel threats of cutting off the water supply. There is no wonder that Singapore has deemed it necessary to find an alternative route to supplying its people and businesses with water. To do just that, the city-state released research funding in 2008 as an incentive to establish the most viable technologies to recycle water. Containing $3m, the funding pot was by no means modest. Winning the race, global technology giant Siemens wowed those within the executive with a concept that demonstrated minimal energy consumption.

In an attempt to avoid the risk of acquiring any unfortunate nicknames, the authority of Singapore and its refinery partner Siemens have dubbed their carefully distilled product “Newater”. The cost of the project is predicted to offer much in return. “Newater has given us a solution with which we can profit well into the future,” enthused Khoo Teng Chye, CEO of Singapore’s public utility board (PUB). Studies show that Newater is cleaner than the government-issued tap water.

Only two years into its collaborative project, Singapore had constructed five Newater plants, as well as a desalination plant and a new water barrage put in place to increase rainwater supply. Rainwater is by no means available in abundance, and to boost the increasing water demand, further funds will be injected in order to create a second and even larger desalination plant; it is scheduled to launch by 2013. As much as 30 percent of Singapore’s daily water usage is derived from reclaimed sources. A significant part of the supply is used for the production of computer hard drives, a segment in which Singapore is an industry leader, with a mighty 40 percent market share.

A smaller part of the supply ends up in drinking water and allegedly only one percent of Newater is fed into the city’s potable water reservoirs. Indeed, Singapore only offers residents recycled water to drink “indirectly”. Indirect potable use (IPU) is a well established phenomenon that occurs in territories other than Singapore. This can potentially take place when reclaimed water intermixes with groundwater aquifers and the combined sources of water are pumped out and treated once again. Following this string of purifying actions, the water will go though another cleansing act before it might potentially end up in a drinking glass or cooking vessel.

Dry as a bone
The UK might be well-known as a particularly rainy nation, but despite the few Englishmen who leave the house without an umbrella, the south-eastern part of the country has suffered a series of droughts due to below-average levels of rainfall for months on end.  Indicative of the severity of the problem, the rather obscure activity that is the rescuing of fish has seen a surge in activity. These operations usually take place when river levels run naturally low towards the end of summer, but much to the worry of the fish rescue brigade, an alarming number of fish shoals had to be rescued in the winter months last year due to dangerously low water levels across the areas of Kennet Valley and the Cotswolds. Moreover, in April 2012 seven water companies across the UK, including Anglian Water, South East Water, Southern Water, and Thames Water, had to introducing temporary use bans, or as they’re commonly referred to, hosepipe ban’s to ensure supply remained constant.

The situation is serious indeed. Still, the idea of using recycled water is considered a last resort. In 2010, Thames Water established a desalination plant at Becton in south-east London at a cost of more than £250m. So far it has only been lightly used. Instead, and quite rightly, leaders of the water industry are promoting water trading between different regions so as to manage water shortage in certain quarters, such as the badly hit south-eastern region. London Mayor Boris Johnson agrees, and asked in a recent article published in The Daily Telegraph why droughts have to occur at all in the southern part of the country, when given that water flows freely further north. Whether the plan becomes reality remains to be seen. If it doesn’t, some parts of the UK might have no choice but to get used to the idea of using reclaimed water on a larger scale.

Promising discoveries
More and more countries suffer droughts, and the demand for water is set to grow markedly in the coming decades due to population growth and the need for irrigation to grow crops. But one continent is in more desperate need of water than others – Africa. More than 300m people miss daily access to safe drinking water across the continent.

But a recent study has revealed that the notoriously dry cluster of countries is harbouring more moisture than commonly assumed. According to the study, the total volume of water in aquifers underground is 100 times the amount found on the surface. To prove their point and present a map of their discovery, the team has created a detailed map of the scale and potential of the resource. The significance of the resource is high, and plans are now underway to establish how the water can be retrieved. Yet, the scientists involved have stressed that large-scale drilling might not be the best way of increasing water supplies. Although Africa is in desperate need of water, one can’t help but draw parallels between the discovery of this water and the discovery of high-value natural resources such as oil and precious metals, which have caused untold toil and pain for various nations. However, a self-sufficient Africa in the future could catapult the continent, and give it ample footing to usher in untold levels of prosperity.

Related topics: