For the last six years, a power plant in San Luis Potosi, Mexico has bought water from a nearby wastewater treatment plant to use in its cooling towers (instead of using freshwater). This operation, Project Tenorio, a public-private partnership, continues today and has already resulted in the reduction of groundwater extraction of at least 48 million cubic meters (equivalent to 19,000 Olympic size pools) and increased aquifer sustainability.
This is a good example of the water and energy nexus in practice: the wastewater treatment plant covers almost all of its operating costs from this additional revenue stream and the power plant gets a more reliable water source that is also 33% cheaper than groundwater in that area.
Treated wastewater has been used to reduce the water requirements of power plants in several other countries as well, as water supply becomes more variable or disappears. In the US, for example, around 50 power plants are using treated wastewater for cooling in order to adapt to water shortages. However, innovative integrated approaches like these are still more of an exception than the norm.
After an intense and exciting week in Stockholm for World Water Week, it is time to look back at some conclusions of the conference and the way forward for next year. I was in Stockholm as a “Lead Rapporteur” and reported in the closing plenary session on “Cooperation to achieve equity by balancing competing demands”; other teams reported on “Managing waters across borders,” “Responding to Global Change,” and “Closing the science-policy-practice loop” (see closing plenary here). This is my attempt to summarize over 100 sessions, you can find all the sessions in the WWW website.
Next week as thousands of practitioners gather at annual World Water Week in Sweden the focus is on cooperation, echoing the UN’s declaration of 2013 as the International Year of Water Cooperation.