Yellowish water: what does it mean?

July 3rd, 2021

Montrealers are privileged to have access to clean drinking water from our municipal water supplies and we are accustomed to seeing clear water flowing from our taps. Occasionally, however, the water from our taps is cloudy or discoloured. As the plumbing specialists serving Montreal’s West Island communities, we’re often asked:

● Why is my tap water yellowish?
● Is it safe to drink tap water that isn’t clear?
● Can I do laundry when the taps are running yellow?
● Do I need to do anything to fix yellow tap water?

In this article, we’ll look at what causes our drinking water to turn yellow sometimes, how to identify where the problem is, and what, if anything, you need to do about it. As always, if you have any concerns about your drinking water, call 311 to find out if there are any precautions or advisories in effect for your neighbourhood.

Causes of yellow tap water

Discoloured tap water with a yellowish tinge is most commonly caused by rust particles in the water and is not a serious concern. While it is not pleasant to look at, trace amounts of rust in water does not pose a health threat and is safe to consume.

If you are on well-water, other causes of a yellow hue to the water coming from your taps include organic material, decaying vegetation, and/or a build-up of iron and manganese. In these cases, property owners relying on well water instead of municipal water lines should work closely with water specialists. These other sources of yellow discolouration do not typically occur in municipal water supplies.

Finding the source

Rust in the water coming from your taps can generally be traced to one of these three sources:

● the municipal water supply
● your indoor plumbing and fixtures
● your hot water heater tank

If you are concerned about the amount of yellow tinge in your drinking water, the first step is to identify where the rust is coming from through a process of elimination.

Is it a municipal water supply issue?

Municipal water mains are “flushed” every few months to help clear away any rust accumulation in the main lines. It is common for the water to absorb some of the rust particles and turn yellow. The discolouration typically goes away as quickly as it started and is nothing to be concerned about.

To find out if your water has turned yellow due to the municipal water supply, try these steps:

● Ask your neighbours if they are experiencing the same issue.
● Call 311 to find out if there are any current advisories in your area.
● Check for notices from the City of Montreal about maintenance, breakages, defective equipment or water contamination.

If none of these reasons appear to be the cause of your water discolouration, you can turn next to finding out if it is coming from your hot or cold water taps.

Is it from your hot water heater tank?

Rust can accumulate in your hot water tank and could be a sign that it’s time for some maintenance, repairs, or even replacement. If the rusty or yellow water is coming from your tap only when the hot water is turned on, then you know that that is the source of your problem. Having your tank inspected and flushed by a professional plumber is the best way to keep your hot water running clear. And hot!

Is it from your cold water taps only?

If you have eliminated the municipal water supply and your hot water tank as a source of your yellowish water, then the problem most likely lies within your plumbing pipes. A sure sign that you have rusty pipes is when the water comes out as yellow or rust-tinted when you first turn on your cold water tap, and then clears up after a few seconds once the surface rust has been dislodged.

If your water is yellow because of deteriorated plumbing in your home, this cycle of yellow-clear-yellow-clear water will grow worse with time. If you suspect that you have rusty pipes, it is essential to have them inspected by a plumber and replaced before they start to leak and/or burst.

Doing laundry with yellow or rusty water

If you are concerned about doing laundry when your water is running a bit yellow-ish, here are some tips for helping to prevent any permanent discolouration on your fabrics:

1. Run a short cycle of at least 5 minutes with no laundry or detergent to help flush the lines first.
2. Use cold water with phosphate detergent and oxygen bleach
3. Avoid the use of chlorine bleach because it will set stains instead of lifting them
4. Add 1 cup of vinegar to both your wash and rinse cycles; it’s a natural rust remover
5. Spot clean any remaining rust stains with vinegar before putting them in the dryer to avoid setting the stain

We’re here to help

If you have concerns about yellowish tap water, rusty pipes, flushing your hot water tank, or any other residential plumbing concerns, don’t hesitate to contact us. Plomberie Richard et Fils Inc. handles both large and small plumbing issues for our clients on the West Island of Montreal and we offer 24/7 emergency services as well. For all your plumbing needs, trust our experienced team of plumbers – we’re here to help!