Is the pendulum swinging back? Will centralised sewerage systems soon be eclipsed by decentralised waste treatment?
by David Schaub-Jones
In November 2011, Jefferson County, Alabama made world news by filing for the largest ever American municipal bankruptcy. Bad housing loans? Pension liabilities too great? No, it was the huge cost of investing in new sewers that tipped them over the edge.
Around the same time, a thousand miles to the North, the municipalities on Cape Cod, Massachusetts, were holding public meetings to discuss options for dealing with their own waste burden. Nitrates from the tens of thousands of on-site facilities are leaking into the groundwater, posing pollution concerns - decentralised treatment seems to them to offer a robust and perhaps cheaper alternative to investing in a centralised system.
In a hundred years time, American historians looking back may see these two events as signalling the moment the pendulum started to swing back – i.e. the point at which the dominance of sewage systems (that rely on treated water to flush waste into our rivers, streams and oceans) started to erode.
History has certainly had its impact on sanitation. A hundred and fifty years ago those living in Minneapolis, USA, hired ‘scavengers’ to periodically clean out and remove the contents of their privy vaults. Night soil got its name as it was removed at night; indeed city ordinances across the USA required latrines to be emptied solely at night. Minneapolis’ first sanitation ordinances sought to control the process of night soil removal and disposal, and the means and hours of transportation, by requiring all the scavengers to be licensed. Amendments to this licensing process continued up until the mid-1930s.
By then however, massive investment had been made into centralised treatment works to channel and treat sewage. Public sanitary reforms in the United States took their lead from the sanitation revolution that had spread from Britain – from where a drive for urban drainage and centralised sewerage had spread to most of the developed world. Huge public investment was poured into centralised sewerage and the business of emptying latrines and transporting the waste to the fields was relegated to a backseat (except in China where waste was valued as manure).
The new sewage networks not only required public investment to build, but required significant technical skills and finance to operate – the diverse pattern of ‘small business’ that had previously dominated sanitation was swept aside, replaced by public ownership of a public service, paid for by municipal taxation.
In developing countries, where still now only 2 in 5 people have access to sewers, ‘on-site sanitation’ as it is known, remained a common practise. Whilst towns remained small and urban agriculture commonplace, the reuse of the waste as fertiliser was widespread. Over time though, towns grew into cities and fields separated from housing. Industrially produced fertiliser became cheaper and more available. As a consequence, the practicality and attractiveness of using latrine waste on fields correspondingly reduced. But as recent events on the East coast of the United States show, perhaps the pendulum is shifting back.
‘On-site sanitation’ and other alternatives to large centralised sewage networks are starting to be taken more seriously. The existence and potential of small, medium and large businesses working in sanitation are also increasingly recognised. It is true that an increasingly urbanised world faces a growing sanitation challenge. But taken together, these two trends are helping shed more light on what options there are to dealing with this challenge – not just in developing countries but also in the developed ones.
There are several contributing factors to this shift, including:
- Water scarcity. As economic growth continues and human population, industry and agriculture all grow, water availability decreases. In arid countries such as South Africa this is reaching crisis point – in South Africa fully 98% of available water has already being allocated to different users. In such contexts the wisdom of using water (and not only that, but treated water piped to the home) to flush toilets is starting to be questioned.
- The large costs of sewerage. Sewage networks are not cheap. Nor are waste water treatment plants. These costs have succeeded in tipping more than one developed country municipality into bankruptcy. In 1850’s Britain, the cost of providing sewerage was thought to be a necessary investment in the face of worsening epidemics in its rapidly urbanising cities. We know more now about the spread and control of disease and we’ve also explored other ways of treating and re-using waste (as anyone who has ever seen the Space Shuttle will tell you).
- Climate events and resilience. As climate change becomes a reality we are becoming more aware of the need for our urban systems to be resilient in the face of stronger and more frequent climate ‘events’. As the flooding of New Orleans made us painfully aware. Sewerage networks are complex systems, with pipes and other infrastructure buried underground. They are thus especially vulnerable in the face of such events. Growing calls for resilience are pushing urban researchers in the North to rethink how they handle municipal services. As a consequence, interest in decentralised waste treatment and ‘resilient systems’ is growing.
- Environmental impacts. The flushing of household waste into our river systems and into the sea is being increasingly questioned. With less water in the rivers and more waste being generated, the carrying capacity of the environment to deal with and process our waste is being further strained. Greater environmental awareness is bringing with it wider appreciation of issues such as ‘dead zones’ in coastal areas (particularly where untreated waste is discharged through sea outfalls).
- Rising fertiliser prices. Phosphorus is a finite resource and the concept of ‘peak phosphorus’ - akin to that of peak oil - is gaining adherents. A lot of phosphorus is carried in human waste; environmentalists and others would rather this was viewed as a valuable resource than as a noxious waste. For African farmers in particular there should be a solid business case – rather than transporting in expensive chemical fertiliser from afar they can turn to local sources of fertiliser ‘production’.
- The green economy. The notion of a green economy – where businesses and others contribute to growth and service delivery in an environmentally friendly way – is gaining ground. The idea is that businesses can “do well by doing good” and thus help to safeguard the planet for future generations.
How a pendulum swing could benefit slum sanitation
Are we really starting to see a significant move away from centralised sewerage systems that rely on water to carry our waste away? Is the pendulum really swinging back?
Perhaps yes, perhaps no - no doubt any shift will take a long time. But the ramifications for developing countries could be huge. In Africa at least, very few countries have succeeded in putting in place sewerage networks of any great scale. Many inherited their networks at independence and these have not always been well maintained (never mind kept pace with rapid urbanisation). Yet attention to other forms of waste management has been minimal; mostly those ‘without’ have been left to fend for themselves. Research and development into alternatives has been minimal and when it comes to technical choices, engineering approaches and norms and standards, professionals in the sector have generally taken their lead from developed countries.
If developed countries, for a range of reasons, start to take decentralised waste management more seriously, then we could see an important paradigm shift. Suddenly decentralised sanitation could be an issue for new towns in the developed world and not just the preserve of slums in the South. This would attract not only money and capacity into innovation and design, but would also alter the status of on-site sanitation more broadly. The water and sanitation sector itself could start to take on-site sanitation more seriously and local governments become more likely to invest and support it. Standardisation should see costs come down and processes become more sophisticated and robust. Financing should become more commonplace and easier to secure, and business models more apparent.
A vision of the future? Maybe. But one thing is for sure - Jefferson County - and the investors underwriting its $4.2 USD billion debt - surely wish there had been alternatives to the sewerage investment that drove it bankrupt!