Iron in water is a vexing issue for homeowners, especially those on well water. Doubts creep in as you pour a glass of water and glimpse its reddish hue. What does it mean to have iron in your water? Is it harmless or a cause for concern?
In this comprehensive guide, we’ll unravel the mysteries surrounding iron found in water. What are the sources of iron in drinking water, the negative effects, and most importantly, how to remove it!
- Iron in water can be either ferric iron which is insoluble, or ferrous iron which is soluble in water. When water contains ferrous iron it becomes oxidized and turns into insoluble ferric iron that leaves reddish-brown stains and corrodes plumbing.
- Iron in water is an “aesthetic” contaminant that has an EPA limit of 0.3 mg/l, however, iron is rarely found at concentrations higher than 10 milligrams mg/L and is typically safe to drink.
- The best method to detect iron in water is to use a certified laboratory test that scans for iron and other common well water contaminants to provide the exact concentration levels.
- The most effective treatment to remove iron from water is a sediment filter, ion exchange, greensand filtration, or ultrafiltration. The best solution will depend on the type and level of iron present.
Types Of Iron In Water
Iron can manifest in different forms, each with its own characteristics and implications in water. Understanding these various types of iron is essential for effectively addressing water quality concerns. Let’s explore the most common forms:
Insoluble Ferric Iron (Fe+3)
Insoluble ferric iron (Fe+3) refers to iron not soluble in water and often appears as reddish-brown particles or sediments. This form of iron is responsible for the staining of fixtures, laundry, and plumbing.
Water containing high levels of insoluble ferric iron can leave unsightly marks on sinks, tubs, and clothing, causing frustration for homeowners.
Soluble Ferrous Iron (Fe+2)
A type of iron that is dissolved in water, making it invisible to the naked eye. This form of iron is responsible for many of the taste and odor issues associated with iron-contaminated water.
When water has a high concentration of Fe+2, it can impart a metallic taste and a reddish or yellowish color to the water.
These are microorganisms that thrive in environments with high levels of iron. They feed on iron and can form slimy biofilms or growths in water systems. These bacteria are not harmful to humans but can contribute to the formation of iron-related problems, such as clogged pipes, stained fixtures, and unpleasant tastes and odors in the water.
Organic Bound Iron and Tannins
Organic bound iron refers to iron that is naturally occurring and complex with organic matter in the water. This type of iron is often associated with high levels of tannins, which are natural organic compounds found in soil and vegetation. Organic bound iron and tannins can cause water discoloration, leading to a yellowish or brownish tint.
How Does Iron Get Into Water?
Iron can find its way into water through various mechanisms, and understanding these sources is essential for identifying the potential causes of iron contamination. Let’s explore the different ways iron can enter the water:
- Naturally-occurring sources: Iron is a naturally abundant element in Earth’s crust. As water percolates through soil and rock formations containing iron minerals, it can dissolve and carry iron particles into groundwater sources. Shallow soils with high iron content can contribute to elevated iron levels in wells and groundwater.
- Corrosion of iron or steel pipes: In cases where water travels through iron or steel pipes, corrosion can occur over time, releasing iron particles into the water supply. Older plumbing systems or lines with poor protective coatings are more susceptible to corrosion, increasing the likelihood of iron contamination.
- Bacterial activity: These are microorganisms that naturally occur in soil and water. These bacteria can metabolize iron, and their growth can contribute to releasing iron particles into the water.
- Industrial and agricultural activities: Certain industrial processes and practices may introduce iron into water sources. Industrial activities involving iron or steel production, mining, or wastewater discharge can result in elevated iron levels in nearby water bodies. Similarly, agricultural activities such as irrigation or using iron-based fertilizers can contribute to iron contamination in water sources.
- Decaying organic matter: Natural organic materials, such as leaves, plants, and organic debris, can release organic acids into the water as they decay. These organic acids can facilitate the dissolution of iron from surrounding soil or sediment, increasing the iron content in the water.
What Are The Effects Of Iron On Drinking Water
Iron in your water source may have various effects on the overall quality and characteristics of the water. The effects are:
- Reddish-brown stains. Iron in tap water can cause unsightly reddish-brown stains on plumbing fixtures, sinks, toilets, and appliances.
- Metallic taste and odor. High levels of soluble ferrous iron (Fe+2) in water can give it a metallic taste and unpleasant smell, making it less enjoyable to drink.
- Discolored water. Iron can cause tap water to have a rusty, red, or yellow color. This discoloration becomes more visible when the water settles or is exposed to air due to reddish-brown ferric iron (Fe+3) formation.
- Clogging and plumbing issues. Excessive iron found in water can lead to pipe and plumbing fixture clogs. Over time, iron deposits accumulate, reducing water flow and pressure. These deposits can break loose, causing intermittent bursts of discolored water.
- A build-up in appliances. The presence of iron found in water can result in the buildup of iron residue in appliances like dishwashers, washing machines, and water heaters. This reduces their efficiency and can potentially cause damage.
- Altered appearance and taste of food. Food-dissolved ferrous iron can impart an undesirable metallic flavor to the water.
- Dry, itchy skin. Iron-laden water used for bathing or showering can dry out the skin. The interaction between soap and iron can leave excess residue, causing dryness and itching.
- Bacterial overgrowth. Iron bacteria can create rust and bacterial slime when combined with iron in your water.
How Much Iron Is Safe In Drinking Water?
The safe level of iron in drinking water is recommended to be below 0.3 milligrams per liter (mg/L), according to the Environmental Protection Agency (EPA) in the United States.
Because iron is considered a secondary contaminant, the current limit is based on the appearance and taste of the water rather than detrimental health effects.
How Do You Test For Iron In Well Water
When it comes to testing for high iron levels in well water, the following methods are commonly considered the best options:
Certified Lab Test
The most reliable and accurate method to test for iron is to collect a water sample and send it to a certified laboratory for analysis.
I recommend Freshnss Labs water test that utilizes sophisticated techniques to precisely measure iron concentrations and other heavy metals. Within 3 business days, you will receive a comprehensive report with any contaminants detected, any health or plumbing alerts, and the best treatment methods based on your data.
Test Strip Kits
Test strip kits are convenient and affordable for detecting iron in your water supply. These kits contain strips coated with a chemical reagent that changes color in the presence of iron. You can estimate the iron concentration by dipping the strip in a water sample and comparing the resulting color to a provided color chart. While test strip kits provide quick results, they may not offer the same level of accuracy as certified lab tests.
Iron Bacteria Test
Specific tests are available if you suspect the presence of iron bacteria, which can contribute to high iron levels and other issues. These tests are designed to detect and identify the existence of this bacteria in water samples. They often involve culturing the sample on specialized media to observe bacterial growth. Confirmatory tests may be required for accurate identification.
How Do You Remove Iron From Well Water?
Iron treatment methods considerations should be considered when choosing a water purification system. Here are different types of iron filters that you can use to remove iron from your drinking water.
Sediment Filter (best for ferric iron)
Sediment filters are best for removing ferric iron, which is insoluble and appears as rust flecks in water. These iron filters physically block iron particles and sediment from entering the water supply.
Ion exchange water softeners or manganese greensand filters effectively remove small amounts of ferrous iron (less than 1 ppm iron). Water softeners use an ion exchange resin to attract and remove iron ions from the water, while manganese greensand oxidizes ferrous iron and filters it out.
Greensand filtration is suitable for higher amounts of ferrous iron. The greensand media oxidizes ferrous iron to ferric iron, which is then trapped and filtered out.
Ultrafiltration systems are recommended for removing tannins and organically bound iron. These systems use a semipermeable membrane with a very small pore size to remove small particles, including organically bound iron.
Shock chlorination is the most effective method for removing iron bacteria, which can cause red or orange sludge and unpleasant odors. This treatment involves introducing a concentrated chlorine solution to the well and plumbing system to eliminate bacteria, followed by filtration or other iron removal methods.
Furthermore, dealing with organic iron and tannins during water treatment poses challenges. Their presence can impede or prevent iron oxidation, making conventional methods like water softeners, aeration systems, and iron filters less effective. Considering chemical oxidation followed by filtration could be a viable solution in such cases.
Frequently Asked Questions
What are the signs of iron in water?
The most common signs of iron in well water are reddish-brown stains on plumbing fixtures and appliances. The water may also have a metallic taste or odor. With iron bacteria, you may experience bacterial overgrowth, including rust, bacterial slime, and bad odors.
Is it safe to drink water with iron in it?
Yes, small amounts of iron in water are not harmful and can be safely consumed. Iron is an essential mineral for the human body and is even required for certain bodily functions.
Should I test my well water for anything besides Iron?
It is advisable to test well water for various contaminants once a year, not just iron. While iron testing is essential, other parameters should also be considered to ensure the safety and quality of your well water.