2013 Flagging Program

The beautiful view from the boat

Last week, we officially wrapped up the 2013 flagging season. We completed the last round of water sampling on the Charles River on Wednesday morning. This time, we shared the river with more rowers than usual, who were probably preparing for the Head of the Charles regatta. As we drove the boat down the Charles towards the Longfellow Bridge, I reflected on my experience doing the flagging sampling. If I could summarize my overall experience in two words, they would be: memorable and meaningful. In fact, although I had prior experience conducting water sampling, this was my first time sampling in the middle of a river, rather than on the banks. Moreover, this experience helped me visualize everything I learned about the Charles River in my Water Quality Control class last year. 

 

Ali and I on my first day on the river

Ali taking a water sample at the Longfellow Bridge

CRWA conducts the flagging program every year from early July through mid-October to provide the public with up-to-date water quality information for the Lower Charles River Basin. This is done on a daily basis through the website, phone hotline, and email list. The flagging program was designed to evaluate whether or not bacteria and cyanobacteria levels in the Charles River meet state health standards. Water samples are collected at four locations along the river twice a week and sent out to a lab to be analyzed for Escherichia coli (E. coli). E. coli is a species in the fecal coliform group used to indicate the presence of pathogenic microorganisms that inhabit in the intestinal tract of warm-blooded animals. The presence of E. coli in the water indicates recent contamination from human or animal waste. The US EPA recommends E. coli as a better indicator of health risk for recreational waters (US EPA 1986). In addition to the weekly sampling, a statistical model was developed by CRWA to give a conservative estimate of water quality conditions. For more information about the flagging program, visit the Water Quality page on CRWA website.  

  

Cristina driving the boat

Taking everything into account, the water quality was generally satisfactory this year. Compared to last year’s sampling program, more blue flags were predicted by the model this time around. The highest concentrations of E. coli at all four sampling locations were noted on July 24^th, 2013. In this instance, red flags, indicating potential health risks, were predicted by the model. This may have been the consequence of heavy rainfall, which may have resulted in the introduction of pollutants into the river from storm drains and combined sewer overflows. Besides, a discharge from the MWRA Cottage Farm Pretreatment Facility was noted on that day. 

My first time driving a boat :-)

Although there are many challenges facing the Charles daily, CRWA has come up with a practical means to evaluate its water quality to protect river users from potential health risks: the flagging program. As mentioned previously, it has been a real pleasure to be part of this year’s sampling team. I have enjoyed every moment on the river. It made me purposeful and happy to be part of a team that aims to protect human health and the environment. I am truly going to miss those beautiful sunny days on the river. 

I am going to miss them too :-(

-Awa

References:

US EPA, 1986. Ambient water quality criteria for bacteria. Report Number EPA440/5-84/002. U.S. Environmental Protection Agency, Office of Water, Washington, D.C.