Wednesday, August 29, 2018 - 7:30 PM

Fact Sheet on Manganese

Manganese at Petty Harbour Long Pond: Answering Some Common Questions

“The information on your website contradicts itself -  you are saying if it’s clear its fine to drink, however your website says Manganese can be in water that is colourless and odourless…”

Manganese is a naturally occurring element that is found in our water all the time. It is not harmful to us – in fact it is an important element we need, at the right levels, for good health including strong, healthy bones and blood.

Water that contains manganese may be coloured, but not always. It would not have a distinct smell or taste. Monitoring results from the City of St John’s indicate that when the water is clear, Manganese levels are below Health Canada’s maximum acceptable concentration.  The City will continue to monitor the levels to ensure that this remains unchanged.

Here’s what Health Canada says about manganese in our drinking water:

Manganese has long been considered to only be an aesthetic concern in drinking water, responsible for staining fixtures and laundry. However, new scientific studies are showing health effects related to exposure to high levels of manganese in drinking water. Other studies show that the human body absorbs more manganese from drinking water than from food. This new information was used as the basis for the new guideline for manganese in drinking water, in order to protect the health of Canadians.

The guideline was established to be protective of the most sensitive population, which is formula-fed infants. If the manganese level in your drinking water is above the guideline, you should consider using an alternate source of water to reconstitute infant formula.

For adults and older children, who drink less water based on body weight than bottle-fed infants, short-term exposure to manganese in drinking water slightly above the guideline is not a concern. However, if this is a long-term situation, a permanent solution such as the use of a treatment device or an alternate source of drinking water should be considered.

“Environmental Public Health at Eastern Health would like to assure residents on the Petty Harbour water supply that the manganese levels reported are only a health concern to infants under 1 year of age.  People caring for infants who are being fed mixed formula are specifically advised to use an alternate source.  Infants who are breastfed would not be at risk. Infants fed premixed formula are not at risk but alternate sources of water should be used when these infants are given water to drink.  Older children, adults and seniors would not experience health concerns at the reported levels of Manganese.”   - Chris Nolan, Manager of Environmental Public Health, Eastern Health

 “How high are the levels of Manganese in our water?
Health Canada advises acceptable levels of manganese in water are 0.12 milligrams per litre for maximum acceptable concentration (MAC).

Normally, our water is well below acceptable levels. Since July 26, of 86 samples, 14 per cent of our samples have been over the maximum concentration. The samples ranged from a minimum of 0.009 mg/l to a maximum 0.525 mg/l with an average sample of 0.076 mg/l, which is below the MAC.

“Should I boil my water?”
No. Boiling the water will have no impact; it will still have the colour. Boil orders are only necessary and effective when there is a bacteria in the water. This issue has nothing to do with bacteria. Manganese is an element not a bacteria.

What should I do if my water is discoloured?
Run your taps to see if the water clears. If you do not see an improvement, please use an alternative water supply and notify Access St. John’s by either calling 311 or 754-CITY (2489), emailing, by the online web submission at or via the app 311 St. John’s.

“Is everyone served by Petty Harbour Long Pond impacted? Why is my water brown and my neighbours’ is not?”
No, not everyone is impacted. This is one of the reasons why it has taken us a little while to identify what the actual issue might be. We aren’t exactly sure why this is, but here’s what we suspect: the water itself, in the pond, has a slightly higher level of manganese than normal and as it is flowing through the pipes to some properties, it is “picking up” other manganese deposited on pipes and raising the overall manganese level in the water that comes out some taps. It is important to note that problem is not consistent and your water may be clear one day and discoloured the next.

This is not an uncommon occurrence - in fact, you might know friends and relatives in other places in the province who have experienced this in their towns. We’re working with experts on this matter now to help us identify ways we can address this – first at the neighbourhood or street level and then with our water system overall. Unfortunately, we do not know at this point how long this will take.

How long has the City known about this and how long will this issue continue? What is the City doing to correct this situation?
The City monitors the quality of our water daily over the entire system, and it is important to note that the quality of our water is amongst the best in the country. The City is very serious about protecting the integrity of our water system and does not take any unnecessary risks with public wellbeing.

We commonly get complaints about discoloured water. This can be caused by a number of different factors, but it is most commonly corrected by flushing the system.

Things started to unfold early August, but results were not consistent; an area with high Manganese one day had low levels the next.  Only localized areas were affected, as is the case today.  Based on the number of complaint areas and our analysis, the City decided to err on the side of caution and notify the public yesterday.

This situation is not the same as the “musty odour” issue we communicated on in July.

City staff are actively working to address this situation. In the short term, we have consulted with experts in water quality on measures we can take to reduce the level of Manganese in our water and in our pipe, including new technologies and water main cleaning. Over the long-term we will be investigating additional treatment process at the Petty Harbour Long Pond Water Treatment Facility.