The linear to circular shift for wastewater in Latin America

Daniel Nolasco, Diego Rodriguez, Hector Serrano, Anna Delgado and Gustavo Saltiel outline the opportunities for sustainable wastewater measures in Latin America and the Caribbean.

Statistics highlight the water and wastewater infrastructure shortfall in the Latin America and Caribbean (LAC) region, and the corresponding investment needs to meet this shortfall.

In 2017, the population of the LAC region reached 644 million, 80% of which lived in urban areas. According to the 2018 Revision of World Urbanization Prospects (UNDESA, 2018), by 2030, the total population in the region will be 718 million, with an urban concentration of 84%.

Regarding access to water supply and sanitation, historically, countries in the region have prioritised investments in water supply, achieving good coverage. According to data from 2017 (WHO and UNICEF, 2019), around 97% of households had access to an improved source of drinking water, although this average hides the gap between rural (88%) and urban (99%) coverage and does not reflect the sustainability and quality of the level of service. Indeed, the share of the urban population with access to safely managed drinking water services was only 74%.

About 87% of the region’s population had access to some form of basic sanitation, with an important difference between rural (70%) and urban (91%) areas. It is estimated that only about 66% of the population is connected to a sewerage system (18% in rural and 77% in urban areas) and only about 30-40% of the region’s wastewater that is collected is treated (FAO, 2017). This latter value, however, does not reflect the quality of the discharged water or whether it complies with the regulation.

“As lessons learned indicate, investment in technology alone will not guarantee meeting the SDGs”

These figures are surprisingly low, given the region’s levels of income and urbanisation, and have significant implications for public health, environmental sustainability, and social equity. In comparison, in the countries of the Organisation for Economic Co-operation and Development (OECD), 81% of the population is connected to a sewerage system and 77% of people benefit from wastewater treatment by being connected to a wastewater treatment plant (OECD, 2017). Furthermore, wastewater management and treatment levels vary widely across LAC countries, and regional averages mask this significant variation.

The investment needs to meet the UN Sustainable Development Goals (SDGs) for sanitation are significant (anywhere between $3.4 and $11.8 billion per year for the period 2016–30). To improve the wastewater situation in the region, countries are indeed embarking on massive programmes to collect and treat wastewater. There is a huge opportunity to ensure that these investments are made in the most sustainable and efficient way possible. As lessons learned in LAC and other regions indicate, investment in technology alone will not guarantee meeting the SDGs. There is a need in the region to plan and invest better.

Opportunities of circular economy principles

The challenges mentioned above present an opportunity to plan and invest in sanitation services in a new way, particularly in wastewater treatment. The long-standing, linear approach of abstracting freshwater from a surface or groundwater source, treating it, using it, collecting it, and disposing of it is not sustainable any more.

Future urban development requires approaches that minimise resource consumption and focus on resource recovery based on circular economy principles (see box). It is for this reason that in 2018 the World Bank launched the ‘Wastewater: from waste to resource’ initiative in the region, to raise awareness of wastewater’s potential as a resource. This article is based on findings of that initiative.

At its core, a circular economy aims to design out waste and improve resource efficiency to achieve sustainability. Waste does not exist; products are designed and optimised for a cycle of disassembly and reuse.

In line with this, wastewater should not be considered a ‘waste’ any more, but a resource. However, in most countries of the region, sanitation and wastewater treatment services are still thought out and planned in a linear way. Furthermore, very often water supply is planned first, sewerage systems are planned next, and energy inputs for both are sometimes only considered once the systems have been designed and constructed. In order to change how institutions approach wastewater, a paradigm shift is required in the region. Wastewater should not be seen as a burden to governments and society, but as an economic opportunity that can be turned into a valuable resource (Figure 1).

In addition to resource recovery, circular economy principles require the optimisation of the use of the existing infrastructure. In layman’s terms, do not expand an existing plant without understanding its real treatment capacity and bottlenecks.

LAC has already very good examples of water resource recovery facilities. To mention a few:

• San Luis Potosi, Mexico, and Projecto Aquapolo, Brazil, sell treated wastewater for reuse to industry and cover part of their O&M costs
• Atotonilco de Tula, Mexico, and La Farfana, Chile, generate energy for self-consumption and generate revenues by selling biogas, respectively
• Minera Cerro Verde, Peru, covers all capital and O&M costs while treating municipal wastewater to reuse it in its mining operation, while discharging treated water to the receiving water body
• CAESB, Brazil, reuses the biosolids generated at its wastewater treatment plant operations to recover degraded areas and as fertilisers in agriculture (see box)
• AySA, Argentina, found ‘hidden’ treatment capacity by evaluating the actual performance of its wastewater treatment plants, avoiding unnecessary expansions of about $150 million.

Cost-saving and environmental considerations are among the main reasons to incorporate circular economy principles in wastewater treatment plants in LAC. The challenge remains one of scaling up the successful experiences and projects.

Fostering these new business models with extra revenue streams would, in turn, attract the private sector to close the funding gap. The private sector is often reluctant to invest in the sanitation sector given the low return on investment and the high risks. There is a need for an enabling environment that fosters business models that promote a shift from waste to resource and that enables private investment in infrastructure in tandem with improved efficiency in public financing to promote sustainable service delivery, especially in the poorest countries. Most of the examples cited above have active participation of the private sector, proving that the concept is feasible and attractive.

Conclusions

The implementation of circular economy principles in LAC and other regions in the developing world is key to reducing capital and O&M expenditures and, thereby, is at the crux of the sanitation conundrum. Numerous examples in the region indicate that this move towards a circular economy is possible. The World Bank ‘Wastewater: from waste to resource’ initiative identified four key actions to achieve this:

• Develop wastewater initiatives as part of a basin planning framework to maximise benefits, improve efficiency and resource allocation, and engage stakeholders
• Build the utility of the future by shifting away from wastewater treatment plants to water resource recovery facilities, thus realising wastewater’s value
• Explore and support the development of innovative financing and sustainable business models in the sector
• Implement the necessary policy, institutional, and regulatory frameworks to promote the change.

Note

This article is based on: Rodriguez, Diego J, Hector Alexander Serrano, Anna Delgado, Daniel Nolasco, and Gustavo Saltiel. 2019: “From waste to resource: Shifting paradigms for smarter wastewater interventions in Latin America and the Caribbean.” World Bank, Washington, DC.

Daniel Nolasco is President of NOLASCO y Asociados S. A. and Chair of IWA’s Strategic Council.

Diego J Rodriguez is Senior Water Resources Management Specialist, Water Global Practice, The World Bank.

Hector Alexander Serrano is Water Resources Specialist, World Bank.

Anna Delgado is a Water Technology and Policy Specialist consulting for the World Bank.

Gustavo Saltiel is Lead Water and Sanitation Specialist, World Bank.

The principles of a circular economy

A circular economy is an industrial system that is restorative or regenerative by intention and design. It is an economic system aimed at minimising waste and making the most of resources. The traditional approach is based on a linear economy with a ‘make, use, and dispose’ model of production. The circular economy approach replaces the end-of-life concept with restoration, shifts towards the use of renewable energy, eliminates the use of toxic chemicals that impair reuse and return to the biosphere, and aims for the elimination of waste through the superior design of materials, products, systems, and business models.

The three main principles of the circular economy are:

(i) design out waste and pollution,

(ii) keep products and materials in use, and

(iii) regenerate natural systems.

Sources: Ellen MacArthur Foundation; WEF, 2014.

Using biosolids in agriculture in Brasilia, Brazil

For several years, the Companhia de Saneamento Ambiental do Distrito Federal (CAESB), the water and wastewater utility of Brazil’s capital district, has been reusing biosolids from its wastewater treatment plant operations to recover degraded areas in its railway operation areas (patios ferroviarios) and in agriculture. The effects of using biosolids on corn production were evaluated, comparing them with a mineral fertiliser mixture consisting of equivalent amounts of nitrogen, phosphorus, and potassium. All grain yields were higher than average for Brazilian standards for corn. The biosolids were, on average, 21% more efficient than mineral fertilisers. Similar studies of soybeans have shown that biosolids were, on average, 18% more efficient than mineral fertilisers. Therefore, the beneficial use of biosolids can lead to higher crop yields and at the same time save significant transport and landfill costs for the water utility.

Aguas y Saneamientos Argentinos (AySA)  

AySA was planning the expansion of several of its WWTPs. The expansion was thought to be needed since the nominal (design) treatment capacity of these facilities was going to be reached in the near future in terms of the incoming wastewater flow rate. A field study was carried out on these facilities to determine the actual capacity of their unit processes. The results of these process audits found hidden capacity in at least seven of these facilities, thereby cancelling planned expansions. Unnecessary expansions are a waste of resources that could be redirected to better use by, for example, building more capacity – for example, new plants – in areas with no coverage (see table).