On February 13, Humboldt Baykeeper staff and 20 trained Citizen Scientist volunteers monitored water quality after a storm at 29 sites in the Humboldt Bay area. This monitoring event was held to compare mid-winter water quality with previous results from “First Flush” monitoring (just after the first major rainstorm of the year), when pollutants that have built up over the dry season are suddenly flushed into waterways).
Samples were analyzed for pH, temperature, conductivity, fecal coliform (E. coli), phosphates, heavy metals, nitrates, and dissolved oxygen.
Click HERE to enlarge map.
Since 2005, our water monitoring efforts have found extremely high fecal coliform levels after “First Flush” compared with “Dry Weather” monitoring done in August.
In many streams, the levels are much higher than the recommended limit for recreational waters (waters that people come into contact with while swimming, wading, surfing, boating, etc.). The recommended limit is 400 MPN/100 mL is the limit for recreational waters, while <1 MPN/100mL is the standard for drinking water.
In 2009, 42% of our sites were considered unsafe for contact recreation during dry weather monitoring (>400 MPN/100 mL). During First Flush, 85% of our sites had E. coli levels above 400 MPN/100 mL. In mid-winter, after several months of rain, 64% of the sites exceeded 400 MPN/100 mL (see graph below).
Fecal coliform are bacteria that originate in the feces of warm-blooded animals, including livestock, wildlife, pets, and humans. This form of water pollution can be reduced by protecting native vegetation along streams and wetlands, limiting livestock access to streams, proper maintenance of septic systems, and proper disposal of pet feces.
To protect people from exposure to this type of water pollution from eating shellfish, commercial oyster beds in the bay are required to suspend harvest after rainstorms. On average, local shellfish beds are closed for 30 days each year due to fecal coliform in runoff.
Humboldt Baykeeper is currently seeking funding to more intensively study watersheds with the highest levels of E. coli, with the goal of identifying the sources and ultimately reducing or eliminating this type of water pollution.
Click HERE to enlarge the graph
Citizen Scientist Jon Lee sampling Upper Jolly Giant Creek, 2/13/12
photo by Todd Kraemer