Monday, August 29, 2011

Wascana Creek Polluted and at Risk?

Pelicans in foamy Wascana Creek - photo by Shelley Banks
Pelicans in weird June foam,
Wascana Creek, 2011 c SB
Regina, Saskatchewan: A creek running through the centre of the city sounds idyllic — until you realize that the creek in your city may be an effluent-dominated ecosystem, and in winter, treated sewage effluent may make up almost 100% of its stream flow. 

From peaceful to perturbing in one easy headline. And the headlines have been flowing all afternoon.
To be fair — if that's the right word in this context — the major pollution starts at our local sewage treatment plant, west of Regina, and flows from there downstream, away from the city. So the part of the creek that's in the city itself is not sewage-laden.

But whether it's what many of us would call clean is an entirely different matter.

The pictures above and below show a group of pelicans, just west of the Albert Street weir earlier this year. It was the first day of summer and the City had just opened the weir under the Albert Street Bridge to release high flood water from Wascana Lake.The result? The water quickly churned into huge curds and billows of foam that engulfed the feeding pelicans.

Pelicans in foamy Wascana Creek - photo by Shelley Banks
A cluster of six pelicans swim through foam -- I've highlighted two.  
At that time, I wondered what created this foam, and whether this foam — and the water it thrashed from — was safe.

Today, I asked Peter Leavitt, a biologist at the University of Regina who studies water quality, those questions.

Here's what he had to say about the water, the foam and the studies:
The foam is not likely to be directly toxic to the birds.  It arises because there are very very high levels of phosphorus and dissolved organic matter in the water.  Think of this as a grass stain on clothes and the detergent.  When you mix the two together (in a washer, or in the lake as water passes under Albert St), you produce foam. 
Today's study is not directly related to the foam or the birds - the authors studied the water quality upstream of the City (which would be similar to the site where the birds are located), and downsteam of the wastewater plant outfall (processed sewage), which is North and West of the City. 
They found potentially toxic levels of nitrogen in many seasons (which might harm the birds) at that second location, as well as antibiotics and other personal health care products which are released into the creek from wastewater.  Birds would also be at risk from toxic cyanobacterial blooms which occur in downstream lakes (for example Pasqua) as a result of the City pollution.  
Thus, the water flowing through the city of Regina is cleaner than the water that flows downstream away from us, where the levels of various elements including nitrogen were extremely high. And one problem with high nitrogen, as Leavitt told the LeaderPost, is that with increasing levels,  "Not only do we get more algae, the algae we get are more toxic."

But nitrogen, ammonia, and phosphates aren't the only things Regina is washing downstream.

The studies also found that pharmaceuticals and personal care products were always present in the water, and this mixture included antibiotics, analgesics, antiinflammatories, a lipid regulator, metabolites of caffeine, cocaine and nicotine, and an insect repellent, as well as "ibuprofen, naproxen, gemfibrozil, triclosan, erythromycin, trimethoprim, and sulfamethoxazole at concentrations that may present a risk to aquatic organisms."

So the pelicans were likely safe when I saw them submerged in foam back in June — as long as they stayed east of the sewage treatment plant. Good news, I guess, although somehow, it's difficult to feel particularly happy about any of this...


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