Bonvehi Rosich, Denizen release “Thinking Through Soil”

Assistant Professor Seth Denizen and Visiting Assistant Professor Montserrat Bonvehi Rosich’s book, “Thinking Through Soil: Wastewater Agriculture in the Mezquital Valley,” will be published this spring. The volume deeply explores the soil — which they describe as one of the globe’s most understated and under-researched resources — in the Mexico City and Mezquital Valley region through scientific, historic, and urbanist lenses. Both Denizen and Bonvehi Rosich teach in the Sam Fox School’s landscape architecture and architecture programs.

Today, a 30-foot pipe carries combined sewage of 22 million people 60 kilometers from Mexico City to irrigate the agricultural Mezquital Valley. This system results in soil contaminated by industrial waste, pharmaceuticals, parasites, and more, which poses significant implications for public health outcomes.

At the same time, reusing wastewater increases the area’s climate resilience. Denizen and Bonvehi Rosich write that “over the next few decades, wastewater reuse will become a necessary and unavoidable part of addressing water scarcity in a warming world.”

With this case study, the authors ask not only what Mexico City would look like if sustainable, high-quality wastewater was sent to the Mezquital Valley, but also what a better environmental future could look like for all of us — and if soil, with its capacity for growing food and storing carbon — holds the answer.

“Thinking Through Soil: Wastewater Agriculture in the Mezquital Valley,” will be available through Harvard Design Press in April 2025.