Image: Eldrich Press (historic photo) and Scape/Landscape Architecture
By Sheila Walsh Reddy, senior scientist for sustainability science
A few hundred years ago, swamps were downright un-American. Swamps were “not only the antithesis of the pastoral ideal, but a very real obstacle to commercial prosperity,” writes historian Anthony Wilson in the Shadow and Shelter: the Swamp in Southern Culture.
Colonial Americans saw putrid waters teeming with alligators and disease. And they went to great lengths to wipe away these biblical images of sin and impurity to make way for the amber waves of grain.
Thomas Jefferson gave encyclopedic advice to gentlemen farmers in Notes on the State of Virginia, but he never breathed a word about The Great Dismal Swamp or other vast wetlands. Draining and filling of wetland up and down the east coast made Jefferson’s image of America nearly a reality by the mid-1900s.
Fast-forward to the 1990s and wetlands have been re-branded. They are a technocrat’s dream, naturally cleaning water and boosting bird populations at the same time.
Like a movie on rewind, towns and some small businesses flood dry lands to construct wetlands to replace wastewater treatment facilities. Ribbon cutting ceremonies feature proud mayors and wise engineers. There is no mention of swamps because modern scientific classification schemes have relegated the term to a subclass of wetlands. By the end of the 90s, there are over 1,000 constructed wetlands in the USA and over 5,000 in Europe (EPA 2004, Cooper 2007).
Success! A triumph for people and nature!
The updated statistics must show constructed wetlands in the 10s of thousands by now, right? In fact, the statistics and the studies tell another story—a story of stagnation (yes, pun intended). But, this story has a lot to tell about what we need to do next to really launch and sustain investment in natural infrastructure.
Demand for constructed wetlands was outstripping supply in the 1990s. This gap attracted sub-par engineers and contractors. Soon, there were constructed wetlands that were not doing their jobs— and instead were stinking cesspools. A few bad experiences changed the public image of constructed wetlands. Maybe it was the collective conscience recalling the putrid waters of sin and impurity.
In the UK, design engineers, contractors, water utility companies, and researchers responded to this problem by forming the industry association, the Constructed Wetland Association (CWA) (Cooper 2007).
The CWA establishes and maintains standards for constructed wetlands through research, training, and accreditation. Similar efforts occurred in the US, with the EPA issuing design manuals, fact sheets, and compiling a database of constructed wetlands. EPA guidance even focused specifically on the dual goals of water quality and wildlife habitat.
The key lessons from these experiences are that we need information that can demonstrate the promise of natural infrastructure as well as standards that help can avoid empty promises. New information can re-brand wetlands from something that is perceived as harmful to something that is helpful. But, for that branding to stick, it needs to be backed by credible standards that ensure that, in fact, wetlands are consistently helpful.
Standards for natural infrastructure will be especially important when the downside risks are large: pollution spilling into drinking water sources or storm surge harming people and property. It seems that most of us are hardwired to avoid these sorts of risks, which could explain why a few poorly constructed wetlands nearly ruined their public image forever.
The constructed wetland that turned into a cesspool had all the ingredients of an image that was made to stick, according to the six attributes of sticky ideas laid out by authors Dan and Chip Heath. It was simple, unexpected, credible, concrete, emotional, and it was told as a story. In contrast, making a switch away from that image requires planning and repetition, that’s where the standards come in.
Despite the image crisis, constructed wetlands have had notable successes with treating municipal wastewater. But, arguably they have not been as successful as they could have been and they certainly have not been widely adopted by some of the biggest producers of wastewater: large businesses.
However, this all may be starting to change. Just this past summer, The Nature Conservancy worked with The Dow Chemical Company, Shell, Swiss Re, and Unilever to issue a joint-industry white paper on natural infrastructure. The white paper was a critical step in demonstrating the potential promise of natural infrastructure solutions, like constructed wetlands, in a business context. Taking a look back at a 110 acre constructed wetland that Dow installed in 1995 in Seadrift, TX, they found that the capital costs for the wetland were $1.2 to 1.4 million as compared to $40 million for an engineered solution. In addition, the wetland has been doing what it was designed to do— clean water— consistently for 15 years. It has also been providing habitat for deer, bobcat, birds, and, yes, alligators.
This information and a set of standards for large businesses could solidify the brand of constructed wetlands as one of a suite of best available technologies for wastewater treatment, setting off a new wave of investment in natural infrastructure.
But, there is still the question of whether the story of the successful constructed wetland will be stickier than the story of the would-be-gator that crawled out of the wetland and ate a deer during lunch last Tuesday.
Wetlands provide numerous benefits for nature and people. Photo: Ken Miracle
2013. The Case for Green Infrastructure: Joint-Industry White Paper.
Cooper, P. 2007. The Constructed Wetland Association UK database of constructed wetland systems. Water Science & Technology 56:1-6.
EPA. 2004. Constructed Treatment Wetlands. US Environmental Protection Agency.
Heath, C. and D. Heath. 2007. Made to stick: Why some ideas survive and others die. Random House Digital, Inc.
Heath, C. and D. Heath. 2010. Switch: How to change when change is hard. New York: Broadway Books.
Wilson, A. 2005. Shadow and Shelter: The Swamp in Southern Culture. Univ. Press of Mississippi.
Opinions expressed on Cool Green Science and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy.