Thursday, 24 April 2014 00:02
According to the 2012 statistics of the Sanitation Bureau, only 2.4% of the Sri Lankan population has access to collective sanitation while 84% of the population uses individual sanitation which consists of a septic tank that then discharges into a combined (wastewater and rainwater) sewer network without further treatment. The rest of the population uses latrines.
As drinking water coverage is almost 100%, sanitation is now becoming one of the main priorities in terms of public investment, and cities in Sri Lanka will experience tremendous change in the coming years.
Lack of effective sanitation has a negative effect on public health: Everyone can appreciate that wastewater in open sewers generate bad smells and is a breeding ground for pests such as mosquitoes, cockroaches and rats, which spread diseases. This has to be considered in light of the recent dengue outbreaks.
"Sanitation infrastructure should be built as early as possible once water supply is available, to avoid groundwater pollution, promote a healthy urban environment and minimise investment cost. Moreover, the building of infrastructure alone is not enough to achieve efficient sanitation: water and sanitation management also involves pricing definition, financial and technical management and social acceptability"
Moreover, providing an increased water supply without proper sanitation to the population leads to higher sewage quantities produced and discharged. Untreated sewage in turn contaminates surface and ground water, which then contaminates wells and water intakes, leading to an increase of water-borne diseases such as diarrhoea.
Achieving a solution before an urbanisation boom
Sanitation investment is now rising dramatically in the country, with projects being implemented or under appraisal by the National Water Supply and Drainage Board (NWSDB) all over the country; these projects include Colombo and the suburbs, Jaffna, Hambantota and Vavuniya, amongst others.
Agence Française de Développement, AFD (French Development Agency) is also appraising three other projects in the secondary cities of Negombo, Galle and Kelaniya Carrying out these sanitation projects before an urbanisation boom is crucial to minimise costs.
As an example, most of the sewer networks in Paris (France) were built for collecting both wastewater and rainwater combined, before people realised the importance of water treatment. It is now too late to install separate systems, due to the lack of available space and the high cost of digging new drains. As a result, major investments are required to build buffer water storage infrastructure, to avoid discharging untreated water when it rains. Major savings can be done by having separate collection and later treatment systems before dense urbanisation.
Beyond the construction of infrastructure, the development of the service should be environmentally, economically and socially sustainable.
Water and wastewater infrastructure can be originally financed through subsidies by the national government. However, in accordance with the internationally accepted long-term goal , the revenue from consumer payments should cover the cost of the service, to ensure a sustainable long term management of the infrastructure. This guarantees economic sustainability.
Water and sanitation are common goods necessary for life and should therefore be accessible to all, no matter how wealthy. This is what makes the issue so complex, given that providing water services obviously represents a cost and pricing water also avoids wasting too much.
In this regard, AFD is leading a program to promote the economic approach to water demand management at the Marseille Centre for Mediterranean Integration. It consists in several case studies (Jordan, Morocco and Tunisia) as well as several think-tanks and experience sharing workshops. This approach offers a solution to the difficulties encountered by some countries to implement effective management policies. The aim is to provide economic insight based on cost-benefit analysis of the different national policies.
The environmental dimension of sustainability is fulfilled by a proper and efficient management of resources that matches local requirements.
As an example, individual sanitation may be a good solution in low density areas where the septic tank effluents can be discharged directly into the ground or into an environment that can absorb pollution and provide another treatment stage. However, it is less appropriate in populated areas, because the treatment achieved in septic tanks is not as effective as conventional Waste Water Treatment Plant. Moreover, wastewater treatment always creates a hazardous by-product, sludge.
Sludge management in a WWTP is simple, as it can be easily collected and treated; having said that, an individual septic tank requires the set up of a complex sludge management chain, involving collection by sludge trucks, safe disposal and controls to check that the sludge is not just discarded anywhere.
A separate system, with open sewer for rainwater and closed sewer for wastewater is preferable as it decreases odour problems and is generally easier to manage from a technical point of view. Indeed, combined wastewater and rainwater sewers lead to flow variation at the inlet of the WWTP during each rain and make treatment more difficult and unreliable.
In the long term, an environmentally sustainable management requires an integrated resource management policy and water sharing governance that takes into account the multiple uses of water (drinking water, wastewater, irrigation, tourism…).
The third dimension of sustainability, which is crucial for success, is social: the service should be affordable to all. In this regard, one of the solutions is to equalise the cost of sanitation at the national level and have everyone pay the same price. This would mean that city-dwellers would pay a little more to subsidise the country side because the cost of building infrastructure in rural area is higher than in cities.
Also, progressive pricing plans can be implemented so that the first cubic meters purchased are done so at a low price and the rest at a slightly higher price. This would be socially fair, and would benefit the poor. This would benefit to the poor as their consumption is lower than the consumption of the rich who often own swimming pools or are less careful with water consumption.
Private sector participation
Because water is widely considered as a common good that should be available to all, privatisation of water and wastewater services may not be politically accepted.
Involvement of private companies may be beneficial under specific conditions. Indeed, it is now generally agreed that operation and maintenance carried out by the private sector in a competitive market is more cost-effective. In addition, the private sector may constitute a form of investment financing that would allow the Government of Sri Lanka to avoid contracting public debt for water and wastewater project and thereby, allow more projects to be financed.
However, as with every contract with the private sector, public authorities must take the role of leader, regulator and thus exert strict control over the private utility to make sure that proper competition is ensured, and that the services provided meet their contractual commitment. This tough task requires the public water management authority to develop the specific technical, financial and legal skills to supervise the outsourcing of public utilities.
Finally, there are countless examples of failed public-private partnerships in the world. One key factor is that, when a significant investment is made by the private sector, the public authority makes sure that the water price increase to recover these investments remains socially acceptable for the population.
In conclusion, sanitation infrastructure should be built as early as possible once water supply is available, to avoid groundwater pollution, promote a healthy urban environment and minimise investment cost. Moreover, the building of infrastructure alone is not enough to achieve efficient sanitation: water and sanitation management also involves pricing definition, financial and technical management and social acceptability.
The writer is the Project Officer of the French Development Agency (AFD). He is an expert on water and sanitation and has worked in water-related public policies in Grenoble, France.