Secondary Disinfection FAQs
Letters from Fraser Health Authority to the City of White Rock approving monochloramine and chlorine as secondary disinfection methods for the City of White Rock's water system.
About Secondary Disinfection
Why are we adding anything to our water?
- The Fraser Health Authority mandated that a secondary disinfection be added to the City’s water system. The Fraser Health Authority has been closely monitoring the City to ensure that the drinking water is being treated by an acceptable secondary disinfection as a condition of our operating permit. This was as a result of the 2010 Boil Water Notice Report when the water utility was under private ownership.
Does the City have primary water disinfection?
- Neighbouring jurisdictions’ water systems are different than White Rock’s as they require both primary and secondary disinfection and therefore different treatment processes are more appropriate. As White Rock has a groundwater source (confined aquifer/deep wells) it only requires secondary disinfection. The deep wells provide a natural first layer of protection against microbial contamination.
What is secondary disinfectant?
- Secondary disinfection provides long-lasting water treatment as the water moves through pipes to consumers. It also maintains water quality by killing potentially harmful organisms. Both monochloramine and chlorine are secondary disinfectants.
Secondary Disinfection Change
Why is the City switching from chlorine to monochloramine?
- We have tried chlorine as a secondary disinfectant option at the Oxford reservoir but the chlorine is reacting with the naturally occurring manganese causing taste, turbidity (cloudiness), colour, and odour issues. While the water is safe, to control these aesthetic issues, it is necessary to switch to monochloramine as the secondary disinfection option.
- Treating the Oxford reservoir with monochloramine will align it with the treatment process of the Merklin reservoir allowing for a uniform secondary disinfection process common in most jurisdictions.
Why did the City initially decide to use chlorine?
- While experts recommended the use of monochloramine, a group of concerned citizens advocated for the use of chlorine. Council listened to the group’s concerns and directed staff to develop a plan to use chlorine as the secondary disinfection option. The water is still safe but the chlorine is reacting with the naturally occurring manganese in our pipes and is causing taste, turbidity (cloudiness), colour, and odour issues.
Why was monochloramine not used from the outset?
- Both chlorine and monochloramine are effective treatment options and approved by the Fraser Health Authority. While experts recommended the use of monochloramine, a group of concerned citizens advocated for the use of chlorine. Council listened to the group’s concerns and directed staff to develop a plan to use chlorine as the secondary disinfection option.
Has Fraser Health Authority mandated and/or approved the use of monochloramine over chlorine?
- Fraser Health Authority has approved both chlorine and monochloramine as a secondary disinfectant.
Why doesn't the City connect to Metro Vancouver?
One of the reasons is because Metro Vancouver’s water system uses chlorine as a secondary disinfectant. Unfortunately, chlorine will react with the manganese that has built up in our water distribution system for decades as the previous water utility providers did not address the naturally occurring manganese from the source (aquifer), which has built up in the 80km of piping in the system.
When chlorine reacts with manganese, the result is discoloured water. We have found the level of discoloration is simply unacceptable
- More information on the reasons why the City is not joining GVRD can be found under the general Water FAQ page.
Facts About Monochloramine
Is monochloramine safe?
Yes, monochloramine has been used safely in Canada and the United States.
- It has also been used in the Merklin reservoir since 2010 after the E.coli incident occurred when the water utility was privately owned. As a result, since 2010 White Rock residents who get their water from the Merklin reservoir have been enjoying drinking water treated by monochloramine.
Monochloramine approved by the US Environmental Protection Agency, Health Canada, and the World Health Organization among others. Since the 1930s nearly 100 million North Americans have been enjoying drinking water treated with monochloramine including Maui, Boston, San Francisco, Portland, Toronto, Ottawa, Washington DC, Tampa Bay, Pasco, Fort Lauderdale, Waterloo, Edmonton, Saskatoon, Victoria, Abbotsford and Mission, BC. (Click image to enlarge.)
It also lasts longer in the distribution system, so it does a better job killing bacteria in areas of the water distribution system that are near the end of the pipes, or areas that do not have as high of flow as other areas
Monochloramine-treated water does not have as strong of a taste as chlorine-treated water
What will the impact of monochloramine be?
- Monochloramine does not react to manganese the way that chlorine does. As the water moves through our distribution system, you will see an improvement to the aesthetic issues that the community has experienced such as issues around colour, turbidity (cloudiness), taste and odour.
What are the long-term health effects of monochloramine?
- According to the United States Centre for Disease Control:
“Current studies indicate that using or drinking water with small amounts of monochloramine does not cause harmful health effects and provides protection against waterborne disease outbreaks.”
- It is approved by Health Canada, the US Environmental Protection Agency (EPA), and the World Health Organization amongst others.
- Since the 1930s nearly 100 million North Americans have been enjoying drinking water treated with monochloramine including: Maui, Boston, San Francisco, Portland, Toronto, Ottawa, Washington DC, Tampa Bay, Pasco, Fort Lauderdale, Waterloo, Edmonton, Saskatoon, Victoria, Abbotsford and Mission, BC.
- These studies looked at monochloramine levels of less than 50 mg/L in drinking water.
- The Canadian standards for monochloramine levels are up to 3 mg/L in drinking water and White Rock levels will be around 1 mg/L.
What is the amount of ammonia that will be added and will there be an impact on my health?
- The amount of ammonia added until now is 0.05 mg/L. Health Canada's Guideline for Canadian Drinking Water for chloramine is not to exceed 3 mg/ L, therefore, the amount the City is using is low. Furthermore, once ammonia is introduced into the system it will react with chlorine and form monochloramine. There are no health implications for monochloramine under the 3 mg/L concentration level set by Health Canada.
Does using monochloramine increase the cost of water?
- There will be minimal budget implications due to the fact that the City already has the pumps for the ammonia application. The cost of the addition of approximately 0.1 mg/L would be a very small addition to the operation cost. In addition, there should be cost savings when the staff time flushing in areas of complaint are reduced and the eliminating the additional flushing of the entire system.
Do home water softeners remove monochloramine?
- Most water softeners are not designed to remove monochloramine.
Does bottle water have monochloramine?
- Normally it does not. Bottled water could contain monochloramine if the company uses water supplied with monochloramine in its water source.
What does chloraminated water taste like?
- Monochloramine itself is colourless, tasteless and odourless. In comparison to chlorinated water, chloraminated water does not have a strong chlorine taste.
If monochloramine is such an effective disinfectant, why is it not used in every community?
- While the public often considers all drinking water to be the same, the local raw water and water distribution conditions determine the best option for each particular community.
- Both chlorine and monochloramine have their own advantages and disadvantages. Given sufficient contact time, monochloramine is as effective as chlorine in destroying bacteria. While chlorine works more quickly, it does not last as long in the water as monochloramine.
- The City is utilizing chloramination as the water from the aquifer does not require primary treatment. The disinfectant is added to ensure the quality of the water is maintained throughout the distribution system.
- Since the 1930s nearly 100 million North Americans have been enjoying drinking water treated with monochloramine including Maui, Boston, San Francisco, Portland, Toronto, Ottawa, Washington DC, Tampa Bay, Pasco, Fort Lauderdale, Waterloo, Edmonton, Saskatoon, Victoria, Abbotsford and Mission, BC.
Is monochloramine safe for swimming pools?
- Yes. Your pool still requires a free-chlorine residual to delay algae and bacterial growth. Test kits measure free-chlorine residuals and can be used with confidence. Contact your local pool supply store for details.
Will monochloramine make my water clear?
- As the water moves through our distribution system, the aesthetic impacts from the chlorine reacting with the naturally occurring manganese will be reduced.
- Fraser Health Authority has approved both chlorine and monochloramine as a secondary disinfectant.
Previously it was said that monochloramine is harmful to fish. Is this true?
- Chloraminated water that gets into our storm drains and streams through lawn watering or other release is diluted enough that it will not harm fish. Monochloramine is already entering our storm drains and streams as the Merklin reservoir has been treated with monochloramine since 2010.
- Fish do absorb monochloramine directly into their bloodstream through their gills which, at higher levels of concentration, can damage the gill tissue and enter the red blood cells causing a sudden and severe blood disorder. For fish owners, monochloramines can be removed from the water by using a water conditioner. Your pet supplier should be able to provide any further guidance you may need on these products.
What precautions will the City take?
- The City recognizes that there are potential impacts to the environment with the use of monochloramine. Water Utility staff will carry chemical pucks and bags to neutralize the monochloramine in the unlikely event of a water main break. This type of response is common and is required for any treated water that is released to the environment, including water treated with chlorine.
- Since 2010 there have been no issues.