Louisville Water’s Scientists and Expert Noses Provide a Clue on the City’s “Mystery Smell”

Louisville Water’s Scientists and Expert Noses Provide a Clue on the City’s “Mystery Smell”
March 2, 2015

It’s no secret that Louisville Water is serious when it comes to the taste of the drinking water.  Scientists are meticulous in the recipe for Louisville pure tap®.  So when Louisville’s Air Pollution Control District needed help in solving the mysterious smell in the city, Louisville Water’s scientists were able to provide a clue.  

Two of Louisville Water’s scientists, Dr. Rengao Song and Mark Campbell, were able to offer information into “geosmin,” an organic taste and odor compound.  Your nose is sensitive to geosmin – some humans can detect it as low as five parts per trillion. Dr. Song and Mark suggested the Air Pollution Control District test the soil for geosmin because when it gets wet it can release an odor. 

The Air Pollution Control District researched the issue and now reasonably confident this is, in fact, the source of the smell.  

What the Air Pollution Control District is managing is not a drinking water issue – it’s merely an environmental smell issue. Louisville Water’s Water Quality department conducts 200 tests a day to ensure our water is safe, both in taste and smell, before it ever reaches a customer’s faucet.  

Photo credit: The Louisville Times, archives

Thankfully, advances in science no longer require Louisville Water to keep a Chief Taster on staff.  In the 1940’s employee Chester Tilford served as our Chief Taster.  Chester sniffed and tasted more than 30 different samples of water every day! Legend says he could taste a dead catfish from upriver. Louisville Water nose science! 


Photo credit: The Louisville Times