Wastewater treatment ponds
A modern wastewater treatment plant with ponds that recycle sewage water.

When you flush your toilet, the water goes down the drain. But before it can be safely discharged back into rivers, lakes, or other waterways, that water must be treated.

The process takes a lot of energy. In most places, that energy is costly and creates a lot of carbon pollution.

But that’s changing in Santiago, Chile. There, utility group Suez is working to make its wastewater treatment plants generate as much power as they use.

Giros: “By reducing our energy consumption, being more efficient, this is really fighting against the climate change.”

Ana Giros is a senior executive V.P. for Suez, in charge of international activities. She says the company is using sludge – a byproduct of water treatment – to create energy and fertilizer.

She says the concept is to transform the wastewater treatment plants into production centers for green resources.

Giros: “So whatever comes out of these plants, we reuse. We reuse the sludge for agriculture. We reuse the sludge to have energy.”

… so much energy that the company expects the water treatment plants to be energy self-sufficient and carbon neutral within the next three years.

Reporting credit: ChavoBart Digital Media.