Not a drop to drink

I submitted the article below for the Guardian International Development journalism competition in 2008. While I didn’t get shortlisted, it does explain what my cousin, Sarah den Haring (then de Mowbray) does for a living.

THE CALL OF NATURE

Probably the least alluring of the UN Millennium Development Goals relates to water sanitation.  Sewage is certainly not a sexy subject.  However, under the auspices of ensuring environmental sustainability, the United Nations aims to halve the number of people without access to water sanitation by 2015.

While 2008 has been named the International Year of Sanitation, by 2015 access to water sanitation systems is due to reduce for people in Sub-Saharan Africa judging by current trends.  The Joint Monitoring Programme for the Millennium Development Goals predicts that in 2015 an extra 91 million people in sub-Saharan Africa will not have access to adequate wastewater treatment.

Kenya: a case in point

Kenya is one of the countries predicted to miss its target of halving the number of people without access to water sanitation.  Sarah de Mowbray, a Mombasa-based water and sanitation engineer, is doing her best to counter this trend in Kenya.  A country troubled by recent political conflicts and numerous economic problems, large-scale sewerage works are not top priority for the government.  Sarah’s GreenWater organisation builds a range of sustainable water treatment systems which she argues are one solution to the lack of water sanitation infrastructure in Kenya.

She works on a range of projects, from private houses and eco-lodges, to low-cost housing estates.  A key project, one that she feels can be replicated fruitfully throughout Kenya, was one she undertook at a local prison.  Here, the water treatment system involves collecting all the wastewater from the prison and passing it through a bio-digester.  This produces methane, which provides fuel for cooking.  Following this, the water passes through a number of constructed wetlands receiving microbial treatment in each one, before the water passes out of the system ready to be used again.

Constructed Wetlands and Reed Beds

The systems that GreenWater uses are very simple, and do not even require a pump if there is a suitable slope available.  Both types of system encourage the growth of micro-organisms which break down the effluent.  A vertical flow reed bed is, Sarah suggests, “like a gravel-filled bath with the plug left out.”  Wastewater flows down through Papyrus grasses to the gravel where aerobic bacteria colonies remove suspended solids.  When the water is then drained to horizontal flow reed beds -  “gravel baths with the plug left in” – where air is displaced and anaerobic bacterial communities remove what is left of the pathogens.  Whereas reed beds have no open water systems, a constructed wetland is, to all intents and purposes, a pond fulfilling a similar purpose.  GreenWater prices a project like the one described at around £13,000 for an eco-lodge catering for 168 daytime guests and 48 overnight guests.  This figure does vary with the location of the project since transport is one of GreenWater’s biggest costs.

A Sea Change

Sarah is adamant that a culture change in the way people think about wastewater in Kenya – and all over the world – is necessary.  For Sarah, her work is all about “seeing waste as a resource and not a problem.”  The water treatment systems in which GreenWater specialises allow people to make use of their wastewater.  She explains how the reed beds or wetlands can be productive: “This could be producing some plant matter which is then used as green fertilizer, material for a biogas digester producing methane [used as a fuel], animal fodder, thatching material, material for compost – something useful which people would be prepared to pay for.”  She even suggests that the wetlands can be used for growing fish for human or animal consumption. “There are lots of crocodile farms here, so the fish feed the crocs and the crocs produce leather and meat.”  Sarah’s view is that these systems can pay for themselves by producing something extra, but at the very least, the treated wastewater can be used to irrigate crops – and safely too.  She emphasises that “It means [the] system will be desirable rather than a job which folk shy away from; they see it as an opportunity for making money.”

A Way Forward?

Can GreenWater’s methods be reproduced elsewhere in Kenya and sub-Saharan Africa?  GreenWater would argue that it is essential to do so.  Sarah points out that only 5% of Kenya’s population are on the sewerage network.  In the UK, by contrast, the figure is around 95%.  Presently, local sanitation solutions mean removing solids and attempting to make the liquid disappear in soak pits.  Inevitably, this causes groundwater contamination.  Sarah makes a powerful argument for the usefulness of systems like hers: “Contamination of groundwater is a major problem.  In Nairobi there is a huge aquifer underlying the whole city, but you have to drill a further 200m after you hit water to get to the clean stuff.”  Because reed beds and wetlands are constructed on the surface, there isn’t the same problem with groundwater contamination.  “By retaining water on the surface, treating it to a level whereby it is safe to discharge, this avoids the problem.”

Moreover, using the treated water can have an effect on overall demand for water.  It can be integrated into the water system for use, for example, in toilets.  “Nowhere more than Kenya is the idea of flushing your toilet with drinking water more crazy,” declares Sarah, with good reason.

On a broader level, the UN Millennium Development Goals are not going to be fulfilled in sub-Saharan Africa by large-scale sewage schemes.  The Department for International Development (DFID) states that it would cost an extra £5 billion each year until 2015 to reach the Millennium Development Goal of halving the number of people without access to water sanitation.  Simultaneously, DFID aims to give £95 million a year to sub-Saharan countries from 2008.  Whilst DFID is by no means the sole aid donor in the region and the projects it funds are certainly worthwhile, funds of this size divided between many countries will not be going towards building widespread water sanitation systems on the scale seen in developed countries.