Water Filters Canada Infomration Centre

5 W's of Water Testing - What's Important to Know

5 Ws of Water Testing

Quality Matters

Scientists have long understood the link between unseen contaminants in water and illnesses. And so back in the 1900s, filtration and disinfection became mainstays for municipal water treatment, and regulations for the quality of public drinking water systems were established.

Why Test Your Water?

If your water is supplied by a municipality, large or small, your water supply is tested routinely, at the source. However, many of the pipes buried underneath our cities have been in place since the introduction of wide-spread water treatment. This aged and, in many cases, crumbling infrastructure now poses its own risk, which is why it’s smart to test the water where you use it – at your tap.

But what if you are on a private water supply? That could be a well, lake water, or even a rainwater tank. In these cases, no one is testing your water unless you are. It’s possible that your water was tested when you moved in or drilled a new well, but bacterial water quality changes over time and can be impacted by extreme weather events, land-use changes, or a nearby failing septic system. Many water contaminants cannot be seen or even tasted in water, so the only way to be sure your water supply is safe is to test. Even if the presence of a particular contaminant is readily apparent, such as the red-coloured stains on fixtures left by iron in the water, getting it tested will quantify the problem, making the best water treatment choice easier.

Private water system users are solely responsible for the quality of their water!

drinking fresh water

When To Test Your Water

Well, the simple answer is, all the time. You never know when your water quality might change. But here are some key events you may want to keep in mind as a red flag to test your water:

  • Change to your water’s colour, taste, or odour
  • If someone in your family has or develops a weak immune system from an illness or medical treatment (i.e.: the elderly or very young, cancer/chemo, on dialysis, etc.)
  • A growing family
  • Unexplained gastro-intestinal illness in anyone drinking your tap water
  • Moving into a new home

For private well owners, basic testing for bacteria and nitrates is recommended at least once a year. Other contaminants you may only need to test for once, such as hardness or iron, or infrequently, like radon. But this will depend on the prevalence of naturally occurring substances in the groundwater in your area.

Where To Test Your Water

Where to test water

Understanding Water Test Results

Different labs may present the information a little differently, but one of the key results to look for is total coliform count.

Coliform bacteria are a group of bacteria that can come from many sources. You’ll find them living in soil and decaying vegetation, as well as in the digestive systems of humans and animals. So while most coliform bacteria are harmless, some are not.

If your test results show that there are coliform bacteria in your water, your well may be contaminated with surface water, manure or sewage.

How serious is this? It depends on how high the number is. Table 1 gives the Environmental Protection Agency’s Safe Drinking Water Standards. If your results are borderline, the lab may suggest retesting.

Environmental Protection Agency

Fecal coliforms or E. coli

As well as a total coliform count, your test results may include a fecal coliform count, or E. coli count. Fecal coliforms are types of coliform bacteria that live in the digestive systems of humans and animals. If your test results show any fecal coliforms, your water is contaminated with human sewage or animal manure. It is not safe to drink unless you boil it.

E. coli is an even more specific type of fecal coliform. If your test results show any E. coli in your water, it is not safe to drink unless you boil it.

My water isn’t safe to drink — now what?

Boil Your Drinking Water

While you’re addressing the source of the problem, boil your well water before you drink it or cook with it. To make sure it’s safe, bring it to a rolling boil for a full minute.

Boil Your Drinking Water

To remove bacteria from your well, one option is to “shock” it with a high dose of chlorine. The amount of chlorine you need depends on the depth of your well, the pH of the water and how much slime or biofilm is present. Keep in mind that chlorine is corrosive and should be handled with care. Leave the chlorine in the well for at least 12 hours and then purge the water. Highly chlorinated water is not safe to drink!

Better yet, call in a water treatment professional. An expert will know exactly how much chlorine is required and how to safely dispose of the chlorinated water once the shock treatment is complete.

Retest Your Well

After you’ve shocked your well, wait 24 hours and then retest the water. Next, wait a week or two and then test it again. Once you get two “bacteria-free” results, your water is safe to drink – for the time being.

If possible, address the source of contamination Even once you’ve received an “all-clear,” don’t kick back and forget about drinking water safety.

If your well has been contaminated once, it may get contaminated again. By tracking down the source of the problem and fixing it, you’ll reduce the risk of your well becoming contaminated in the future.

well water

It’s important to remember that shocking your well doesn’t offer a longterm solution for ongoing contamination issues. It’s a quick fix that needs to be paired with long-term disinfection.