Is the tap water in Calgary stinky? Yes. Is it safe to drink? Also yes

The funny taste or smell in the water is caused by geosmin, a bacteria found in both of Calgary's rivers, and its Glenmore Reservoir.   (Scott Dippel/CBC - image credit)
The funny taste or smell in the water is caused by geosmin, a bacteria found in both of Calgary's rivers, and its Glenmore Reservoir. (Scott Dippel/CBC - image credit)

If your tap water tastes or smells a little off — don't panic.

Some Calgarians are experiencing a funny taste or smell in their water, particularly those in the north part of the city.

Mark Crowdis, manager of water quality with the city, said it's because of geosmin, a harmless compound which can be found in the late summer and early fall.

It can produce an earthy or musty taste and smell, but it's temporary. Crowdis was on CBC's The Homestretch to discuss.

The following interview has been edited for clarity and length.

Question: What is happening with drinking water in the city of Calgary right now?

Answer: We are seeing increased levels of what we refer to as geosmin and that is a naturally occurring bacteria that is in both rivers: Elbow River — in our Glenmore Reservoir — the Bow River — in what we refer to as the Bow River reservoir — and it comes to our water treatment plants into our drinking system.

Q: I'm assuming you're saying it's safe as well? 

A: It's safe, we call it harmless for a reason. There's no impact to our actual drinking water quality from a health perspective.

It is actually in our water year-round. However, we see typically in August going into September, the levels start to increase.

Now, this year's a little bit interesting. Because of our low flows in the river, we actually saw our geosmin levels increase sooner than we have in recent years. So we started seeing geosmin increase earlier in August, and that has led to hopefully, what we are predicting, kind of where we've spiked or we're seeing our worst levels now.

And typically October we come down off that trend and we return to more normal levels, where people with sensitive noses or taste buds don't sense it at all.

Q: So what tends to dictate how much geosmin is in the water each year?

A: That's kind of a very interesting question and it's kind of the key component of a lot of the research we're doing. We know that it is a harmless bacteria that occurs or builds in the river sediment and some of the river plant life. We're trying to figure out and research and learn more about what actually triggers increased levels.

There are many different factors that come into play, like I mentioned river flow. We know that dilution isn't always a solution to knocking down some of those geosmin levels, but other environmental conditions like temperature, different river conditions throughout the year can also kind of play with that geosmin level.

Q: Could you describe what geosmin smells and tastes like?

A: If it's been dry, or if there's rainfall overnight, and you first walk outside and you smell that kind of that earthy smell from your grass or from your soils — that's kind of what we're getting in our water.

Q: Is there anything folks can do at home to eliminate that taste and smell?

A: We have been recommending taking lemon slices and cutting them up and putting them in a jug in your fridge.

Sometimes the lemon breaks down that earthy smell, or the cartridge in your Brita filter can also sometimes bring down that earthy smell, musty smell. But if not, just want to remind everyone that there is a harmless taste and odour issue and our drinking water is perfectly safe to drink.