Algae in water

When fertilizer and pesticides run off farmland, they can contaminate waterways with nutrient pollution.

Davis: “A classic example is the Mississippi Basin.”

That’s Ryan Davis of Sandia National Laboratories. He says a lot of the nitrogen and phosphorus that’s applied to agriculture in the Great Plains runs off into waterways that drain into the Gulf of Mexico. Those nutrients cause an enormous algae bloom every year.

Davis: “The costs of that algae bloom are tremendous as far as negative impacts to fisheries and tourism.”

But algae can serve a useful purpose.

Davis: “It can be a great fuel source.”

Growing algae commercially for biofuel is expensive, in part because nutrients must be added. So at a pilot site in California, Davis and his team are using the excess nutrients from farmland runoff to grow algae for biofuel.

Davis: “What we’re proposing is to capture those nutrients in an engineered algae cultivation in an efficient way before they get released into the larger environment and can cause harm.”

By coupling the clean-up of nutrient pollution with biofuel production, they hope to make both processes more cost-efficient. And if scaled up, that means more clean water and clean fuel.

Reporting credit: Daisy Simmons/ChavoBart Digital Media.

Bruce Lieberman, a long-time journalist, has covered climate change science, policy, and politics for nearly two decades. A newspaper reporter for 20 years, Bruce worked for The San Diego Union-Tribune...