Monitoring E. coli Levels in Columbia Gorge Recreation Areas


This summer, Riverkeeper is conducting weekly monitoring for bacterial contamination at four popular recreation sites in the Columbia Gorge. Water samples are collected weekly from the Hood River at Tucker Bridge, and from the mainstem Columbia at the Waterfront Park Swim Beach, the Event Site, and the Inner Hook. Results will be posted on our website weekly. E.coli is naturally found in the intestines of warm-blooded animals, but its presence in river indicates fecal contamination. 

View this week's data

Sampling Sites:

  • Tucker Bridge
  • Hood River Event Site
  • Hood River Waterfront Park
  • The Inner Hook

What is E.coli?

E. coli is a naturally occurring bacteria that lives in the lower intestines of warm-blooded mammals. E. coli belongs to a group of bacteria, some of which are harmful, known as fecal coliform. E. coli is necessary for the digestion of food but its presence in rivers indicates fecal contamination. Common sources of E.coli include overflowing septic fields and sewage systems, and fecal matter from wildlife and pets. In the photo, glowing cells indicate E. coli contamination.

At what levels does E. coli become a concern?

The Oregon state water quality standard says that a single sample shall not exceed 406 colonies/100 mL. The Environmental Protection Agency had designated a federal standard that no single samples shall exceed 235 colonies/100 mL. This number is obtained using laboratory testing of E. coli water samples.

Why test for E. coli?

We conduct weekly E. coli testing on the Hood River at Tucker Bridge, and along the Columbia River at the Hood River Event Site, Hood River Waterfront Park, and the Inner Hook to ensure the health and safety for river-goers and a rapid response to E. coli contamination,if it should occur.

Check back weekly for updated results.

For more information, contact

Check out the article published July 7th, 2011 in the Hood River News: Riverkeeper Starts Monitoring E.Coli on the Rivers