Cincinnati Zoo's mission to be "Greenest" in U.S. continues with stormwater project

Last week the Cincinnati Zoo began work to permanently remove the 17- acre Africa exhibit's stormwater runoff from the ecological nightmare that is Cincinnati's combined sewer system, Zoo facilities director Mark Fisher said.

The partnership between the Zoo and Metropolitan Sewer District will keep an estimated 12 million gallons of combined sewage from entering the Ohio river watershed every year.

The project will replace the asphalt in Africa with ornamental grasses and pervious concrete. An underground storage pipe will re-distribute rainwater from roofs to an irrigation system and decorative pond. One-third of the zoo will be off the sewer grid by the end of 2010, Fisher said.

The project is part of an ongoing, award-winning effort by the Cincinnati Zoo to establish itself as "the greenest zoo in America" and will effectively demolish the old Zoo parking lot: one of many expansive, impervious surfaces lying around Cincinnati that funnel 15 billion gallons of runoff into the Ohio river every year, Fisher said.

During huge storm events, combined sewer lines like Cincinnati's become overwhelmed and raw, untreated human and industrial waste pours into creeks, streams and rivers along with the stormwater runoff.  The EPA says that combined sewer runoff is one of the greatest threats to water quality in the United States.

"Combined sewer overflow is a major problem in Cincinnati, arguably the biggest environmental problem in the city," Fisher said. "The zoo is a huge footprint and we happen to be on one of the worst sewer systems in the city."

In a few years the Zoo will be completely removed from the stormwater sewer grid, except for during the largest rain storms which only occur every fifty years.   It will be another feather-in-the-cap for the Zoo's award-winning green program. Like many green initiatives, the Zoo's efforts were kick started by energy efficiency retrofits that started saving money, and made other ecological initiatives more appealing to the Zoo's decision makers, Fisher said.

"The zoo, like a lot of old organizations, had been stuck in this mentality of 'oh were just a little non-profit and we cannot afford to go green,'" Fisher said. "But our utility bill has been eating us alive, so we spent about a half-million bucks on retrofits four years ago. Our utility bill is down in those four years $1.5 million."

Other green feats at the zoo include a LEED Platinum-certified entrance complex, an elephant-poop-to-fuel project, and a new program that converts restaurant frying oil into biodiesel that will help power the zoo train. 

Writer: Henry Sweets
Photography by Scott Beseler
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