Future of water depends on resource diversification and loss reduction

Event on water security co-hosted by FAPESP featured experts in several areas, such as chemical engineering, geoscience, environmental management, economics and agronomy.

By Maria Fernanda Ziegler  |  Agência FAPESP – Water scarcity has become a major issue for all cities in an age of extreme events and rising demand for water. In this context, the water security agenda calls for extending water resource diversification while promoting the use of new technologies to upgrade distribution networks and reduce losses.

This vision was stressed by researchers who took part in an event entitled “The Future of Water” on March 12, 2018, in São Paulo, Brazil. Organized by FAPESP and the São Paulo State Legislative Assembly Institute (ILP), the event was the fourth in the ILP-FAPESP Science & Innovation Cycle. The participants included State Assemblywoman Célia Leão, ILP CEO Vinicius Schurgelies, and FAPESP CEO Carlos Américo Pacheco. “We never remember water – only when it rains heavily or when we turn on the tap and there’s no water. In any case, water is an absolutely necessary topic, and we need to look very hard at the problem,” Leão said. 

Water reuse was highlighted by José Carlos Mierzwa, Technical Director of the International Reference Center for Water Reuse (IRCWR/CIRRA) at the University of São Paulo’s Engineering School (POLI-USP). “When we think about water resource management in metropolitan areas, all supply options must be considered, including reuse,” he said, adding that reuse is an option to minimize demand for water resources, especially in industrial and urban activities, which can use water of sub-potable quality. 

“Metropolitan São Paulo has a natural scarcity problem. The main approach has been to transport water from increasingly far away. This makes water more expensive and pollution more intense. Worse still, many Brazilian cities reuse water without meaning to,” Mierzwa noted, referring to contamination of water sources by untreated sewage. Unintentional or unplanned reuse occurs when a city discharges sewage into a river and obtains water from the same river further downstream.

“Even discharging treated sewage into the environment creates pollution by chemical contaminants that aren’t affected by the treatment system,” Mierzwa said. “The presence of these contaminants in water supply plants is under discussion in several countries.”

Technology is available to make sure reused water is effectively safe. “What we need to change, perhaps, are the parameters for monitoring this water. The standards in place don’t always identify certain contaminants or their combined action. This is a concern when treating both drinking water and reused water,” he said.

Alternating resources

Better use of water resource diversity was also the focus of a presentation by Ricardo Hirata, a researcher affiliated with the Groundwater Research Center (CEPAS) at the University of São Paulo’s Geoscience Institute (IG-USP). 

“For cities to become more resilient, their inhabitants must look for available water resources. We fail to use many resources that could be used simply because we aren’t aware of their existence. This is the case not just for the general public but also for decision makers,” Hirata said.

His presentation focused on the findings of a study showing that metropolitan São Paulo should ideally work out a way to balance the use of surface water, mainly rivers and reservoirs, and groundwater sources such as aquifers during the year. “This would guarantee water the whole year round, even during a drought, avoiding excessive abstraction from aquifers when river and reservoir levels are low,” he said.

Spain’s capital, Madrid, for example, uses this kind of planned alternation of water resources. According to Hirata, surface runoff is injected into the region’s aquifers during the rainy season to ensure sufficient supply months later, in the dry season. “This could be done here in São Paulo as well. Actually, we’re already doing it but on a completely individual basis,” he said.

The presentation highlighted a fact of which most inhabitants of metropolitan São Paulo are unaware. “Our research shows groundwater accounts for not 1% but 20% of the water used in the metro area,” he said.

Given that the water supply company is responsible for 1% and that the other 19% comes from individual initiatives, which are often unauthorized, in his view, this points to lack of regulation in the sector. 

“Such solutions are individual, and they aren’t regulated,” he said. “If you add up all the wells, they account for more than 10,000 liters per second. That makes them the fourth-largest source of water in the basin. It’s an integrated solution, but it isn’t organized or regulated, making it a problematical model.”

Ademar Romeiro, Full Professor in the University of Campinas’s Economics Institute (IE-UNICAMP) and a senior researcher in the same university’s Center for Agricultural & Environmental Economics (NEA-UNICAMP), insisted on the importance of including conservation in the cost of water. “Water bills should include the price of water, meaning the cost of maintaining the availability of the resource in terms of the requisite quantity and quality,” he said.

According to Romeiro, while water bills are currently based on the cost of distributing water and treating sewage, they ought also to be based on the cost of managing the production of high-quality water in nature and the cost of maintaining rainwater infiltration.

He cited a survey by IE-UNICAMP of Serra da Cantareira, which contains the largest water resources for metropolitan São Paulo. The study found that 40% of the area consists of degraded pasture, which does not contribute to aquifer replenishment.

“More adequate management should include what we call opportunity cost,” he said. “In the case of Serra da Cantareira, we found that BRL 150 million [now about USD 45.4 million] per year would be needed to improve these pastures by paying farmers to invest in reforestation. That’s not too costly, not least because it would avoid having to raise water charges. It would also increase water production capacity,” Romeiro explained.

Another major problem relating to water scarcity is that Brazil loses an average of 40% of its drinking water, owing above all to pipe leaks (which account for 60% of all losses).

Water loss is estimated to amount to BRL 8 billion per year (now about USD 2.4 bn). “If losses were cut by 20%, with the difference, we could supply water to all the Brazilians who currently lack access to potable water,” said Marília Lara, executive director of Stattus4, a startup that has developed a smart leak-detection system called Fluid with the support of FAPESP’s Innovative Research in Small Business Program (PIPE).

The system uses artificial intelligence to detect leaks automatically in distribution networks (read more at agencia.fapesp.br/27471). The data collected by a mobile device is analyzed and classified by the AI software.

The purpose of the ILP-FAPESP Science & Innovation Cycle is to disseminate research with a high social and economic impact that is produced by scientists in São Paulo State and can be used as a basis for public policies that benefit society.

“FAPESP has funded some 1,100 water resource-related projects via scholarships and grants in recent years,” FAPESP CEO Carlos Américo Pacheco said in his opening remarks at the event. “In addition, growing numbers of innovative small firms are working on solutions to improve the efficiency of water resource management. PIPE currently supports tens of innovative firms that are developing solutions in this area.”