Nitrates FAQs
The following outlines important information related to nitrate levels in drinking water.
The following outlines important information related to nitrate levels in drinking water.
Yes, the City’s drinking water is safe and meets all Ontario’s Drinking Water Standards. The City of Brantford places the highest priority on the safety and well-being of our community. We are committed to ensuring that all residents have access to safe and reliable drinking water. Brantford’s water supply is rigorously tested multiple times each day to ensure it meets or exceeds all provincial health and safety standards. These testing measures are part of our ongoing responsibility to maintain compliance with strict regulatory requirements and to provide the highest level of confidence in the quality of water delivered to homes and businesses across the city.
Should there be a need to inform the public of any changes that could adversely affect public health, the City is fully committed to public transparency, and in consultation with the Grand Erie Public Health will provide clear communications to ensure the community is informed and any necessary actions to protect public health are taken promptly.
Nitrate is commonly found in diets through vegetables and fruits, cured and processed meats, fish, dairy products, beers, and cereals. Some meats and meat products contain nitrate which is used as a preservative. Manure and some fertilizers are high in nitrate. Drinking water from wells and surface water can also contain nitrate.
The main source of exposure to nitrates for the general population is via food (either naturally occurring or added as a preservative), followed by drinking water. Nitrate taken up by plants (especially leafy vegetables) can account for about 80% of nitrate in a typical diet.
Nitrate occurs naturally in surface water and groundwater at low levels. They are highly soluble in water so any excess amount of fertilizer rich in nitrate and not consumed by plants in the winter months can move quickly through soil and into surface water and groundwater under certain conditions. High levels of nitrate can also occur from non-point sources such as runoff from agricultural fields, livestock operations and point sources including some wastewater treatments plants that convert ammonia to nitrate and discharge effluent to the Grand River or its tributaries.
During colder months, biological processes in the river slow down considerably, reducing the uptake of nitrogen and increasing the potential for elevated nitrate concentrations. Large runoff events may also have the potential to export large quantities of nitrate to receiving streams and rivers.
The Ministry of the Environment, Conservation and Parks (MECP) has set a Maximum Acceptable Concentration (MAC) for nitrate at 10 milligrams per Litre (mg/L) as nitrogen. No harmful health effects have been seen at levels below the drinking water guideline level of 45 mg/L of nitrate in drinking water (equivalent to 10 mg/L expressed as nitrogen-nitrate).
Health Canada warns that the main health threat to the public when nitrate is over 10mg/L is methemoglobinemia, also known as blue baby syndrome. Therefore, the vulnerable populations at risk from ingesting high nitrate in drinking water, are expecting mothers, bottle-fed infants less than six months old, and babies one year old and under. Infants six months old or under do not yet have the enzyme needed to break down nitrate. There is no conclusive evidence that temporary consumption of water measuring 10 mg/L is harmful to anyone outside of the identified vulnerable populations of expecting mothers bottle-fed infants less than six months old, and babies one year of age and under.
For more information, please refer to the Grand Erie Public Health (formerly known as Brant County Health Unit) website and/or call 519-753-4937 ext. 440.
Residents are also encouraged to review the guidelines issued by Health Canada at Guidelines for Canadian Drinking Water Quality: Guideline - Nitrate and Nitrite.
For more information regarding potential public health impacts, please refer to Grand Erie Public Health (formerly known as Brant County Health Unit) website.
The City of Brantford operates and maintains the City’s Water System and is committed to ensuring a high level of trust, commitment and accountability for the public water supply by consistently delivering high quality and safe drinking water to our community. In November 2024, the Grand River Conservation Authority (GRCA) awarded the City of Brantford Wastewater Treatment Plant a Gold Recognition award for their efforts to improve water quality in the Grand River.
The City closely monitors nitrate levels in the water every winter, and to date, this has not been an issue. To further mitigate this risk, the City has successfully installed four new reverse osmosis (RO) units at the Water Treatment Plant as a proactive measure to reduce nitrate levels in the City’s drinking water. While the City’s water has always remained within safe limits and never exceeded the Maximum Acceptable Concentration (MAC) of 10 mg/L for nitrates, seasonal increases, especially during winter and early spring can occur due to upstream agricultural runoff, livestock operations, and wastewater discharges. RO technology uses high pressure to push water through specialized membranes that remove contaminants, including nitrates, ensuring continued delivery of safe, high-quality drinking water.
Reverse osmosis is one of the most effective treatment methods available for nitrate removal. The newly installed units are already showing positive results, significantly reducing nitrate concentrations in the City’s treated water.
To maintain a reliable drinking water supply for the long-term, the City has a three prong multi-barrier approach that includes the following actions:
Low-income families can apply to Ontario Renovates Program to determine eligibility for subsidy to purchase and install an appropriate Reverse Osmosis device at home to reduce the nitrate level in the tap water. For further details of the Program, please visit our Funding for Home Repairs and Home Ownership page here.
Please refer to Grand Erie Public Health (formerly known as Brant County Health Unit) website for instructions on use of tap water by the vulnerable population (pregnant women, bottle fed infants of less than six months old and babies less than 1 year old.)
The City regularly posts the drinking water quality reports on the City’s website. The reports can be found online here.
For more information residents can call the City’s Customer Contact Centre at 519-759-4150.
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City of Brantford
58 Dalhousie Street
Brantford, Ontario N3T 2J2
T. 519-759-4150
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The public is urged to take precautions as the Medical Officer of Health for Grand Erie Public Health has issued a heat warning, effective July 27, 2025. The alert will remain in effect until a cancellation notice is issued. Read the full public notice at Brantford.ca/Newsroom