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Building urban sewerage infrastructure – but where is the sewage?

Isabel Blackett's picture

The World Bank at World Water Week 2015

Sewage is wastewater which contains human excreta (feces and urine), laundry waste, and often kitchen, bathing and other forms of waste water too. It is highly pathogenic, meaning that it contains many disease causing organisms.

Globally around two-thirds of the World’s urban dwellers rely on on-site (on-plot) sanitation. At the same time there is an increasing trend towards replacing on-site sanitation with traditional sewerage systems. Millions of dollars are spent on building sewers and sewage treatment plants while the complementary investments in household sewer connections and toilets are often neglected. What will those municipal investments in sewage treatment achieve without house connections?

Open combined drain/sewer in Vietnam
Photo Credit: Water and Sanitation Program
A recent study from the World Bank’s Water and Sanitation Program (WSP) examined sewerage projects funded by different agencies in 12 cities of Indonesia and Vietnam. The study found that most sewerage projects focused on the ‘large investment items’ - trunk sewers and sewage treatment facilities - with scant attention, plans or investment in tertiary street drains and sewers or the house connections to collect the wastewater from homes. Unfortunately the sewers were found to collect vast amounts of storm water in the wet season and with little fecal contamination flowing into the sewage treatment plants. In these cases the sewage treatment plants are receiving not much more than ‘dirty water’ – with negligible benefits to public health and the environment. The household fecal wastes remained mostly untouched and uncollected – under or nearby to the home or local drains and waterways – when they should have been connected and removed by the new sewers and delivered to the plants for safe treatment and disposal.

The lessons learnt? That policies, strategies, plans, designs, and financing mechanisms always need to include the ‘last mile connecting infrastructure’ so that households connect to the sewers and transport it to plants for treatment. Reactions to the study from governments and development agencies have been that the findings are a ‘wake-up call’ and changes to the scope of existing and planned sewerage projects to include the tertiary sewers and house connections have already been made in Vietnam. But what do these findings mean for other countries and regions? Do the same lessons learned apply elsewhere?

Related publication: Improving On-site Sanitation and Connections to Sewers in Southeast Asia (PDF)

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Comments

Submitted by Richard Middleton on

Depressing findings. Sounds like a repeat of the Bank's project in Accra (to which no one connected, and which the ASCE used as a case study...!).
And also depressing because the WSP began as a sanitation program (handpumps came much later), following the Bank's findings that conventional sewerage was rarely if ever the optimum solution for developing countries. So we started by promoting unconventional solutions (e.g., solids-free sewerage) and affordable house connections in places where on-site sanitation was inappropriate. The Bank's efforts on Strategic Sanitation Planning were intended to provide the tools to make this part of standard operating procedure.
Have subsequent studies shown that the original conclusions were wrong, or, if they are still valid, have we failed to get our message across?

Thank you for the comment and observations. The conclusions and approach of Strategic Sanitation Planning have not been proved wrong, rather it seems that the time, budget and effort required for dissemination of new solutions; capacity building; and the need for comprehensive regulatory reforms may have been under estimated. Many ‘alternative’ approaches are still viable – alongside more conventional solutions. However, this study showed that the national and local regulations, standards and guidelines are not in place; capacity is low at the local level; and the institutions and approaches are not sufficiently joined-up  between level of government, departments, and the users to enable them to always work effectively.

Submitted by Dean on

Interesting, and consistent with several previous analyses that were done in Vietnam as recently as 2012. The study, however, doesn't seem to take into account significant investment made in household connections and tertiary networks under the large urban upgrading projects in Vietnam, and in such projects as the Ho Chi Minh Environmental Sanitation Project. Future projects in Vietnam may want to look at GPOBA examples in Kenya which pay for household connections for water, sanitation and electricity and which are linked to slum upgrading projects that provide the tertiary and secondary infrastructure.

Thanks for this very valid comment. The study was based on six sample cities selected by and agreed between Government and the development partners who funded them (one project per development partner). The study did not review all such initiatives in Vietnam. However, with the feedback on the study and the increasing interest in the subject we would like to consider reviewing more good examples some years after projects have completed. 

Submitted by jay bhagwan on

The title of your talk was most appropriate. The reality is that we should be leapfrogging the developing world away fro sewerage and wastewater. The Bank should be more instrumental in supporting and investing in new off the grid solutions. It is what is required for the future, today. All the guidelines and tools continue to profess and promote a developed country ideology. Its time to shift the focus and attention, through eliminating sludge/human waste at source. The revolution is starting.

Submitted by Marco Forster on

A recent study shows the seriousness of the idleness of sewage networks and the release of untreated sewage in Brazil. Among the causes of idleness are resistance to invest again (construction of private connection to the public sewer, abandoning the previous investment in septic tanks), to pay tariff, lack of information, lack of sanctions and the presence of watercourse or drainage systems. In some Brazilian municipalities, idleness of sewer network amounts to more than 20%, jeopardizing also the financial feasibility of public sewerage systems if the utility can not invoice the inhabitants not yet connected but living in areas with built networks.
http://www.tratabrasil.org.br/datafiles/estudos/ociosidade/relatorio-completo.pdf and http://www.tratabrasil.org.br/datafiles/estudos/ociosidade/tabela-completa.pdf
National, state and most local legislation is consistent and does not allow doubts. If a sewage networks exist, interconnection is mandatory and subject to tariffs. That is, even the absence of a municipal law, the legal requirement established by national and state law do apply. Unfortunately, many municipalities and utilities do not monitor connection rates nor apply sanctions. If all household comply with the connection requirement, the 47 major Brazilian cities (21% of Brazil’s population) could increase sludge treatment by 16%.

Submitted by Luqman Michel on

You had examined sewerage projects funded by different agencies in 12 cities of Indonesia and Vietnam.Great!
I have done quite a bit of work on the biggest sewerage works in Sabah, Malaysia. It was a RM183 million project. The pipes were not laid properly by the contractor Salcon Engineering Bhd and yet was approved by the authorities despite complaints from the CCTV contractor, UG Management services Sdn Bhd that many defects had not been rectified.
Please read my blog at :www.seweragescam.com for more

Submitted by Ian Pearson on

Hi Isabel,

we have found your publication most helpful. We are dealing with the same issue in Maseru, Lesotho. In this case the networks and bulk sewers were installed in a poorer area of Maseru because of the concern regarding pollution of the main drinking water reservoir. As expected, connection uptake has been low. We are trying to find ways to motivate residents to connect through better financing options, improved property value and convenience, and better regulations and management of connections. Will let you know the outcomes with time.

Thanks Ian, for your message and good to hear that research in East Asia has applicability in Southern Africa – and Jay’s comment suggests that too.  We have more detailed study reports if you would find these useful. Please do let us know about the outcomes of your initiatives to increase connections in Maseru.

Best, 
Isabel

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