Telling the story of water

Dr. David Sedlak wrote a book — THE book — on the evolution of urban water and wastewater systems, and in the process, he noticed an interesting pattern.

Dr. David Sedlak talks with Angela Godwin during the 2019 BlueTech Forum in London.
Dr. David Sedlak talks with Angela Godwin during the 2019 BlueTech Forum in London.

Telling the story of water

By Angela Godwin

American novelist James Baldwin said, “Know from whence you came. If you know whence you came, there are absolutely no limitations to where you can go.” His sentiment is a poignant one that holds its relevance when applied to our modern water and wastewater systems.

“I’d been studying the issue of water recycling and water reuse for about four or five years, and what I found is that people are really curious about this topic,” said David Sedlak, professor of environmental engineering at UC-Berkeley. He said he was surprised, however, by how little people actually knew not only about the topic of water recycling but where their water came from in the first place. “After giving a few talks explaining it, I realized that the thing they were really interested in is knowing the history of how it came about, the problems it’s facing now, and where it’s going in the future.”

Sedlak sat down and wrote a book — THE book — on the evolution of urban water and wastewater systems, Water 4.0: The Past, Present, and Future of the World’s Most Vital Resource. In the process, he noticed something interesting. “What you see is a repeating pattern in urban water systems. That is, we build them, they serve our needs, and then they reach a point where, for one reason or another, they’re not doing what we want them to do anymore. We bump along for a number of decades, making do with the best we have, and then suddenly a crisis happens.”

When that crisis happens, he noted, things change very quickly. The system undergoes a complete transformation. “And then it’s good; it lasts for a while,” he said. Then another crisis happens and the cycle repeats.

Through his research, Dr. Sedlak has been able to identify three major water “revolutions” in the West: imported water (bringing water from long distances and distributing it around cities); drinking water treatment (disinfecting water that might have made us sick); and municipal wastewater treatment (purifying it to protect rivers and aquatic ecosystems). “And now, we’re going through a fourth revolution,” he suggested, “and that revolution is really the thing that’s happening today and that people are really curious to know about.”

The fourth revolution, Water 4.0 as he calls it, is different depending upon where you live. “If you live in a water-scarce place, that revolution is a water supply revolution — things like desalination, water recycling, stormwater capture, conservation.” If you live in a really wet place, however, “it has to do with managing all the water that comes down the streets and not just putting it in a storm sewer and letting it flood the city,” he said.

In the five years since his book was published, Dr. Sedlak, a scientific researcher by nature, has continued to work with his graduate students on new technologies, studying urban water systems and trying to improve them. But he believes another book is likely in his future.

“When I set out to write [Water 4.0], I realized it’s an incomplete story,” he said. His next book, he believes, will attempt to answer the question of where we’re going in the future. “That’s the story that needs to be told next.” WW

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