Watershed-Based Plans for Industrial Reuse of Effluents from Public Wastewater Treatment Plants (WWTPs)
By Ricardo Borsari (São Paulo State Minister, Sanitation and Water Resources), on behalf of the Brazil multi-stakeholder partners
In some metropolitan areas under water stress in the State of São Paulo, domestic supply and economic activities compete for limited natural water stocks and for drinking water from the public systems. In the face of increasing water scarcity, Brazilian law requires that domestic supply be prioritized; companies can thus become more vulnerable to risks and losses. Such challenges need to be dealt with through integrated actions by public and private sectors and civil society.
Water reuse is a strategy to help reduce the competitive pressure on water availability and the risk of exposure to water crises in water-stressed river basins. Some urban and industrial activities do not require high-quality water, and they could reuse effluents from municipal WWTPs instead of taking water from surface and ground sources or using drinking water from the public supply. In the State of São Paulo, state and city authorities, public and private sanitation concessionaires, representatives of the industrial sector, and NGOs have shown increasing interest in promoting investments in reuse projects for such non-potable purposes. However, watershed-based discussions, studies, and plans are necessary since the industrial reuse of domestic effluents is not applicable or feasible in all situations. Effluent quality standards, logistical costs, legal compliance, workers’ health risks, and new business and financing models are all important aspects to be assessed by reuse studies and plans.
Progress to Date
The 2030 WRG succeeded in building common ground with the São Paulo State Department of Water Resources and Sanitation (SSRH), São Paulo State Environmental Agency (CETESB), and Committee and Agency for the Piracicaba, Capivari, and Jundiaí Rivers Basins (PCJ Committee and Agency) on the necessity of watershed-based reuse plans, inclusion of water reuse guidelines into the river basin plans, regional economic-ecological zonings, and local sanitation plans under elaboration or revision. The 2030 WRG helped stakeholders such as the SSRH, PCJ Committee and Agency, United Nations (UN) Global Compact and ArqFuturo NGOs, National Association of Sanitation Engineers, and other water management-focused institutions organize seminars and workshops with strong participation of public authorities and sector representatives, aimed at debating the opportunities and hurdles for water reuse projects for urban and industrial purposes. The international seminar “Water shortage and reuse as part of the solution” represented a cultural change milestone at the high-level (staff of the State government). The Rio Water Week 2018 event brought together global experts and enterprises to discuss water management-related issues under the UN Sustainable Development Goals framework.
The 2030 WRG worked together with the PCJ Agency and Committee, especially with the Technical Chamber for Water Conservation in Industry, in the preparation of a detailed Terms of Reference for a regional study on industrial reuse, which is currently under procurement process. This attracted the interest of the State Sanitation Company (Sabesp), which is prospecting water reuse clients and intends to support new investments in the Alto Tietê river basin.
- It is crucial to work in close contact with existing water management institutions and their representatives in a bottom-up process. By listening to our local and regional stakeholders, we can better understand their challenges and needs, and engage with them to build consistent and consensual solutions.
- It is important to identify opportunities for public and private investments and partnerships at the watershed-based level, that align with the water reuse guidelines set by regional and local plans.
- Building common ground for innovative projects, such as the industrial reuse of domestic effluents from WWTPs, takes time because it involves negotiating demands and adjusting expectations of stakeholders from different sectors.
- Fruitful cross-sector collaboration and coordination could be replicated for other river basins with similar conditions and opportunities, but the effectiveness of the institutional arrangements should be tested locally.