Iron

Iron (Fe) is a naturally occurring metal found in rock and soil. It is commonly present in both surface water and groundwater in New Brunswick. Iron is an essential element required in small amounts by all living organisms.

The most common source of iron in drinking water is natural weathering of rocks and soils, which allows iron to dissolve into groundwater. Iron can also enter drinking water through corrosion of pipes, plumbing and well components. In some cases, mining activities, industrial discharges or landfill leachate may contribute to elevated iron levels. Iron concentrations in well water can vary by season and are influenced by well depth, construction and location.

Iron has an Aesthetic Objective (AO) of less than or equal to 0.1 milligrams per litre (mg/L). This objective is based on taste, odour and staining issues rather than health effects.

Drinking water testing is required to determine the presence and concentration of iron. Samples must be analyzed by an accredited laboratory and collected according to the laboratory’s instructions. Laboratory analysis is necessary to confirm whether iron is present at levels that may affect water quality.

For more information on water testing services, please see: Well water testing. Testing costs vary depending on the laboratory and the number of parameters analyzed.

Iron in drinking water is not considered a health concern at levels typically found in New Brunswick drinking water. High concentrations may cause unpleasant taste, odour and staining of plumbing fixtures and laundry.

Iron is not assigned a health-based Maximum Acceptable Concentration (MAC). Exceeding the aesthetic objective may result in clogged pipes, rust flakes and increased growth of iron-related bacteria, but it is not expected to cause adverse health effects.

When iron concentrations exceed 0.1 mg/L, a second test is recommended to confirm the result. If elevated levels are confirmed, the following actions may help reduce iron in drinking water:

• inspect and properly maintain the well
• consider using an alternative water source
• install treatment to reduce iron levels in the existing supply

Treatment systems may be installed at the point where water enters the home (point-of-entry) or at a specific tap (point-of-use). Common treatment methods for reducing iron include:

• cation exchange
• activated carbon filtration
• oxidizing filters, such as greensand filtration
• reverse osmosis
• some pitcher-style filtration units using these methods may also be effective

Treatment systems should be certified to meet current NSF standards for iron reduction and installed and maintained according to the manufacturer’s instructions. Treatment effectiveness depends on the type of iron present, water pH and iron concentration.

After installation, drinking water should be re-tested to confirm the system is working properly. Ongoing maintenance is essential to ensure consistent water quality.

Additional information on water treatment is available through private water treatment companies or the nearest regional Health Protection Branch office.