Sunday, July 31, 2011

Cracked sewers bleed fecal germs

Over at Science News, Janet Raloff writes about an issue that wins the ew! gross! award for the day, and probably the week. This story raises the question of how pervasive this issue might be, especially since infrastructure in the US is chronically neglected: New studies in California and Wisconsin reveal a dirty little secret: Out of sight, many urban sewer pipes are failing and germ-ridden filth is bleeding out.

The studies tracked material hemorrhaging into storm drains. These pipes, which channel their contents into streams and coastal waters, are designed to collect fairly clean rainwater and runoff from watered lawns. Yet raw sewage at times constituted nearly 20 percent of one local storm drain’s flow, reports Patricia Ann Holden of the University of California, Santa Barbara and her colleagues.

“We found the same thing,” says Sandra McLellan of the University of Wisconsin–Milwaukee. In the August Water Research, her group reports finding a bacterial indicator of human feces — Bacteroides — in samples from all 45 storm water outflows in the Milwaukee area that it monitored over four years. The data show that sewage contamination “is nearly ubiquitous in the urban environment,” McLellan says....

A splendid example of a cast iron sewer vent pipe in Curzon Park North (in the UK). An arrow topped by a "divers helmet" topped by a crown, orb and a pickelhaupt. Shot by Sue Adair, Wikimedia Commons via Geograph UK, under the Creative Commons Attribution-Share Alike 2.0 Generic license

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