Concrete Progress: The Night-Heron Solution

Concrete Progress is an ongoing series of columns by Peter Brewitt devoted to exploring America’s infrastructure. It is part of Orion’s Reimagining Infrastructure project. Top photograph courtesy of Ellen Land-Weber.

The herons glared at me, and I suppose that I deserved it. When I arrived at the wastewater treatment plant in Arcata, California, I had guessed that it would be interesting but I was sure it would be gross. When you visit a sewage plant, you expect to smell it, and while I’d been promised that Arcata’s marsh was a clean and nifty place, I was prepared for a little stink. But no: What I found was a dense and verdant wetland—far more plant than sewage.

I was glad that I’d brought binoculars for the occasion (you can find birds at wastewater facilities the world over), because after a couple of standard ducks I spied a black-crowned night heron, still puffed up against the early morning mist. He gazed skeptically down at me over his feather ruff, the way that one of the nastier kings of Middle Earth might regard a hobbit. And he wasn’t alone. As I hiked on, I found another night heron, and then another, and another—one perched in every bush, each as smug and disapproving as the last. No doubt they were blaming me for making assumptions about their marsh.

But how could I have known? Where other cities build sludge digesters, Arcata has a wildlife sanctuary.

In the bad old days before the Clean Water Act, many communities didn’t bother much with sewage treatment, spewing their lightly processed waste wherever seemed convenient. Eventually America realized that this was disgusting, and a series of environmental laws demanded that communities put their sewage through secondary treatment before releasing it (I wrote a bit about this in December). In 1975, Arcata began to move forward with plans for a new regional plant of the traditional kind. This plant would be ugly, unpleasant, and, even with government help, expensive. But what could a small town do?

Bob Gearhart, a young environmental engineering professor at Humboldt State University, found another solution. He and George Allen, a fisheries professor, saw value in sewage. The two men reasoned that wastewater’s nutrients could sustain plants and animals—much like manure on crops. Why not create a new wetland, and purify effluent at the same time? They sold the idea to the city, which eventually let them try a small pilot project, to see how plants would suck up Arcatans’ recently flushed nitrogen and phosphorus. It worked well. They ramped the project up, and it worked again. By 1986, the whole marsh was up and purifying.

Photograph by Gary Stone, with thanks to Friends of the Arcata Marsh.

The combination of wastewater treatment plant and wetland sanctuary has been a brilliant success. In 2013, Arcata’s marsh covers 307 acres in a series of ponds that transforms sewage (with minimal human treatment) into clean, healthy water far more cheaply than a regional plant. Salmon and steelhead trout thrive, and by the time the effluent reaches Humboldt Bay, it’s pure enough to support a thriving oyster fishery. Many thousands of tourists bring their binoculars to the marsh each year. For years, the city threw an annual “Flush with Pride” party to celebrate its magical wetland.

All right, you might think—this works for Arcata, a progressive town of 17,000 people in the mists of Northern California. But can it work for, say, Phoenix?

Yes, indeed. Phoenix has just finished up its own wastewater marsh on the banks of the Salt and Gila Rivers. The Tres Rios Wetlands Project creates restored river habitat (it too has night herons) to help digest the flood of sewage produced by the sixth-largest city in the United States, as well as provide flood control. It covers 480 acres and houses 179 bird species.

Will you get your own herons? You might. 1972 was a long time ago (consider our society’s progress in shirt lapels and collar width alone) and the Clean Water Act’s wastewater plants, built by less creative cities than Arcata, are getting old. Every year, America’s creaky treatment works spit up 900 billion gallons of untreated sewage—eight gallons, every day, for every person in the United States. In 2013, the American Society of Civil Engineers, in their annual report card, assigned America’s wastewater infrastructure the grade of D. And the pressure on that infrastructure is increasing. As we become an ever more urban nation, cities that once held 582,000 people (Phoenix in 1970) might have to be creative with the effluent of 1.45 million (Phoenix in 2010).

Much has been done—there are over a thousand wastewater wetlands in America already, and Phoenix attacks its water use on many different fronts—but problems remain. Upgrades for conventional wastewater plants will cost hundreds of billions of dollars. Cities scrambling for another way would do well to look to Arcata and its cheap, natural, clean-smelling marshes.

Peter Brewitt has wondered about infrastructure ever since a flood kept him away from three days of kindergarten. He wrote his doctoral dissertation on dam removal politics at the University of California, Santa Cruz, and will begin an Environmental Studies professorship at Wofford College this fall. In his academic work, he researches the ways people decide to restore and remake their environments.


  1. Yessir, the best places to go bird watching in cities as far apart and dissimilar as Austin and Cairo are the water treatment lagoons.

  2. I have read quite a few articles about the Arcata Marsh. This one is excellent! Thank you for covering all the bases. One thing you didn’t put in, probably for space reasons, is that the project was very controversial at the start. George Allen, Bob Gearhart and their team had many hurdles at every governmental level to go over before it was eventually approved.

  3. What happens to heavy metals and other industrial contaminants? I understand these marshes would do very well if our sewers contained only human waste…but they don’t.

  4. John: It’s true – water treatment lagoons are often little islands of habitat in big cities.
    Ellen: Indeed…such things are usually controversial. The focus was more on the environmental impacts, but a longer treatment would definitely have gone into the political challenges.
    Helena: There isn’t much industry in and around Arcata, so as far as I know those other contaminants aren’t a big issue. Someplace downstream of a chemical plant or a military firing range would have to take steps to make sure all this was dealt with.

  5. An old friend of mine owns a house essentially across the street from a sewage treatment plant. It’s a tiny little town, so not much to smell there, but it’s in Maine. All the examples I’m seeing here are from fairly frost free zones. Are you aware of any success stories from chillier climes?

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