Imagine turning the drinking water tap on and having a pink-coloured liquid pouring out instead of clear water. That's what happened to thousands of residents of Canadian town Onoway in central Alberta on Monday (6 March).

The residents of the town took to social media to post pictures of their disturbing finding. They raised a complaint with their mayor, who has issued an apology.

However, the pink water posed no public health risk, Mayor Dale Krasnow said in a statement. He said he wished the residents "could have done a better job communicating what was going on", he added.

He pointed out that the town uses potassium permanganate to treat its well water, but due to some issue with the equipment at the water treatment plant the chemical got into the main water supply.

The chemical is thought to be commonly used to remove iron and hydrogen sulphide from water, according to the BBC.

Upon realising what had happened, Krasnow said, civic authorities immediately drained the reservoir and flushed out all the water in the distribution system.

"The reservoir was drained, however some of the chemical still made it into the distribution system. While it is alarming to see pink water coming from your taps, potassium permanganate is used in normal treatment processes to help remove iron and manganese and residents were never at risk," the statement from the mayor read.

According to the World Health Organization, while the chemical does not cause any adverse effects, it can cause skin irritation.

Local media reports suggest that the town did not immediately issue a public comment over the issue, leaving several residents puzzled and shocked over the bizarre incident. The public were reportedly kept in the dark for a day, until Tuesday morning (7 March).

"This is a situation we can certainly learn from and develop a strategy for better response and communication should we ever face the same or similar situation in the future," Krasnow said.