Interpreting Test Results
Results are posted weekly to the Laurier, Capilano, and Fort Edmonton Footbridge pages on the Swim Guide website and app (you can also follow us on facebook and twitter). The green and red Swim Guide symbols reflect the water quality at the time of sampling and can be interpreted as follows:
This information is intended to serve as a reference point for a wide range of river recreation activities and our test results are equally intended for boaters, anglers, rowers, and others who might not be swimming, but come in contact with the water all the same.
Note that while this data serves as a helpful reference point, it does not provide a comprehensive assessment of all of the risk factors that affect swimming safety. Furthermore, because water quality changes quickly in a river environment, test results only reflect water quality at the time of sampling. To determine the level of risk associated with swimming in the North Saskatchewan River on a given day, recreational users should consider a wide range of risk factors before entering the water.
Rules of thumb: When is the water quality best?
In moving water, the quality can change very quickly and while our test results serve as a helpful reference point, additional judgement is essential.
Delay swimming for 48 hours following a moderate or heavy rainfall.
Much like spring runoff, rainfall causes higher discharges of storm-water, which can lead to poorer water quality and can elevate the risk of contracting an illness and infection through recreational water activities. At certain places downstream of the Rossdale water treatment plant, heavy rainfalls can also lead to discharges of raw sewage directly into the river.
Choose a swimming location away from any stormwater or combined sewer outfalls.
Water quality can also be poorer near the mouths of tributary creeks due to stormwater discharges into these smaller waterways – if swimming near a creek mouth, it is usually best to enter the river on the upstream side of the creek.
Swim when river flow levels are moderate.
High flow levels sometimes lead to poorer water quality and more floating debris (such as large logs), while extremely low levels can make it difficult to swim in shallower parts of the river.
Choose an upstream location for your swimming activities.
Generally, the further upstream you go, the cleaner the water will be. Our test results will help determine the particular levels of risk posed by water quality at upstream and downstream locations within the City of Edmonton and will help us advocate for water management strategies that ensure the river is just as clean when it leaves the city as when it enters.
With the right precautions, swimming in the North Saskatchewan River can make for a safe and enjoyable recreation experience!
The water quality considerations listed here are not exhaustive and recreational water users should ensure suitable conditions and take all safety precautions before entering the water. Click below to learn more about how to mitigate the physical risks inherent in swimming activities.
What are we testing for?
Within city limits, one of the greatest water quality concerns is the discharge of untreated sewage and stormwater directly into the river and its tributaries. With this in mind, our testing targets E. coli as a bacteria indicator of fecal contamination. If E. coli is present, many other contaminants are in the water too and in cases when bacteria levels exceed the federal, acute guideline of 400 units per 100ml, the risk of illness or infection increases above 1-2%, or 10-20 illnesses for every 1,000 swimmers. Note that guidelines in some jurisdictions are much more stringent and are designed to protect more vulnerable demographics including children, who often swallow more water and play in the shallower, more contaminated areas of a beach. Click below to read about our testing methods in detail.
Why is this information important? Water pollution can have adverse effects on aquatic life and human health. Swimming in contaminated water can lead to a variety of illnesses showing symptoms from vomiting and diarrhea to skin, ear, and eye infections. More serious afflictions are also cause for concern due to parasites, bacteria, and viruses that can be introduced by sewage discharges. Read more.