Antimicrobials, perfumes, drugs pose challenges for sewage treatment

CHAMPAIGN, lll. -- Think of it like sourdough. Or beer. Or yogurt. These popular products are all created through a process that involves using bacteria to systematically break down organic matter. Even though the process relies on living microorganisms, it can be mechanized or industrialized for large-scale production.

In his first book, University of Illinois professor Daniel Schneider tackles a similar topic, albeit one not generally discussed at cocktail parties. Schneider’s “Hybrid Nature: Sewage Treatment and the Contradictions of the Industrial Ecosystem” was published last month by the MIT Press.

“Yeah, it’s usually a conversation-ender,” Schneider said. “I mean, nobody grows up saying ‘I want to work on sewage.’ The profession has struggled with an image problem.”

Schneider, a professor of urban and regional planning, became interested in the science of sewage treatment after several years of shepherding watershed planning students on a series of field trips that included the northeast plant of the Urbana & Champaign Sanitary District - a site Schneider described as “a roiling tank of bubbling sewage.” There, chief operator Mike Guthrie (now retired) would give the students a tour and answer Schneider’s questions.

“He would say, ‘Well, you know, if it smells a little funky we do this, and if it looks a little foamy, we do that,’ ” said Schneider, who is also affiliated with the Illinois Natural History Survey , a unit of the Prairie Research Institute. “And as an ecologist, what I saw was that they were managing an ecosystem. Ecosystem management has been a vague but important topic in ecology for quite a while.”

The term “ecosystem management” normally applies to natural environments such as forests, rivers and watersheds. But sewage treatment plants are probably the first and largest example of a different type of complex and ever-growing ecosystem - the industrial ecosystem.

In his book, Schneider traces the history of sewage treatment from the era of honey buckets and cisterns through ash closets and night-soil men to septic tanks and the modern system of activated sludge - a muddy substance imbued with a mixture of bacteria that transforms effluent into water clean enough to discharge into rivers. Along the way, engineers fought over the notion of whether microorganisms and their natural processes could be patented. Legal rulings rendered in those cases established precedents that factor in contemporary biotechnology cases such as salmon farming litigation and Diamond v. Chakrabarty, in which the U.S. Supreme Court ruled that living organisms (in that case, bacteria used to aid in the decomposition of oil spills) could be patented.

Farmers around the world rely on another product derived from sewage treatment: the gene that endows cash crops with resistance to the widely used herbicide glyphosate (marketed under the name Roundup) was developed from bacteria found in the sewage treatment facility used by a Monsanto Roundup production plant. That gene has proved impossible to contain, showing up in wild mustard as well as bentgrass, a prized putting-green turf variety that escaped its trial cultivation plot.
           
“These are indications of how this technology has hybridized with the natural world,” Schneider said. “In a sense, the entire world is becoming an industrial ecosystem.”

Sewage treatment plants are becoming more sophisticated, and the demands society is placing on them are becoming more complex. Household waste now carries pharmaceuticals, antimicrobials and artificial musks used to perfume shampoos and soaps.

“They’re biologically active and disrupt animal endocrine systems, so they’re toxic,” Schneider said.

And then there are other substances that are assumed harmless and not removed.

“You can go out to San Francisco Bay and easily measure the caffeine concentration in the water, just from people peeing coffee,” Schneider said.