Red, Orange, or Brown

Rusty-orange or black staining on sinks, bathtubs, toilet bowls, laundry, and plumbing fixtures are an indication that your water contains excessive iron or manganese. Drinking water may even have a yellow or orange tinge and taste metallic. Iron is typically present in water in two forms: ferrous and ferric

Ferrous iron is soluble, meaning it will dissolve into the water. Water containing ferrous iron will be completely clear since the iron is totally dissolved. When water containing ferrous iron is exposed to air in the pressure tank or atmosphere, it causes the iron to oxidize. The water will become cloudy and a reddish brown substance will begin to form. This sediment caused by the oxidation process is the insoluble ferric iron.

Excess iron or manganese in your water is generally a nuisance but should produce no adverse health effects. However, some harmful bacteria require iron to grow, making their removal more difficult while iron is present. The types of bacteria that use iron to survive are known as iron bacteria. Iron bacteria can leave behind a reddish brown or yellow slime that can clog plumbing and cause unpleasant odors. This slime is particularly noticeable in the toilet tank if the lid is removed.

The first step in tackling a water problem is determining the source. A common way for iron to enter the water is via the corrosion of iron or steel pipes due to low pH water. A water test should be performed to discover the extent of the iron problem and detect iron bacteria as well as identify the pH level, alkalinity, and hardness levels – all of which should be taken into consideration when selecting treatment. Water samples for testing should be collected as close to the well as possible. If your water is from a municipal source, you should contact a utility official to determine whether the red water is from the public system or the home’s own plumbing.

Before developing an iron removal plan, make sure to check for tannins in the water. The presence of tannins in water will complicate the iron oxidation and filtration processes. Iron binds to tannin to create an “organic iron” that prevents oxidation and can pass through filters. Remove any tannins from the water before treating for iron by using activated carbon filters, anion exchange, or chlorination and filtration. Most iron and manganese problems can be treated with a water softener or sediment filter, depending on the type of iron and quantity.

 

Treatment

Before choosing a water treatment method, make sure you consider the following:

  • Type of iron in water system
  • Ability of water treatment unit to remove the total iron concentration indicated by water test results
  • Capability of treatment equipment to treat water at the required flow rate for your water system
  • Other water factors that may affect various treatments such as pH level or temperature
  • Cost of construction of new well or reconstruction of well vs. cost of long term iron removal treatments.

Next, we will look at how to determine what type of iron is in your system and treatment options for each type.

Ferrous Iron

Symptoms
Tap water is clear and odorless when first poured from the faucet. After the water has been standing for a few minutes, reddish brown particles begin to appear and settle at the bottom of the glass.

Treatment Method

Considerations

Aeration/Filtration

Temperature dependent

Water Softener

Hardness should be calculated and increased sodium concentration should be checked if user is on a sodium-restricted diet. System must be airtight

Chlorination/Filtration

Requires frequent monitoring and proper water pressure. May require lengthy contact time.

Manganese Greensand/Filtration

Adequate pressure

Catalytic Filtration

Dissolved oxygen, alkalinity, organic matter, chlorination, polyphosphate, and temperature limitations

Ozonation

Cost

Sequestering (adding chemical agents to water to keep iron in an insoluble, filterable form)

May not prevent staining and may require removal of sequestering agents and iron. Test for agents before choosing another treatment device.

 

Ferric Iron

Symptoms
Tap water appears rusty or has a red or yellow color when poured from the faucet. After the water has been standing for a few minutes, the particles begin to settle at the bottom of the glass.

Treatment Method

Considerations

Chlorination/Filtration

Requires frequent monitoring and proper water pressure. May require lengthy contact time.

Manganese Greensand/Filtration

Adequate pressure

Catalytic Filtration

Dissolved oxygen, alkalinity, organic matter, chlorination, polyphosphate, and temperature limitations

 

Iron Bacteria

Symptoms
Iron bacteria can be detected by the presence of rusty colored or yellow gelatinous slime or sludge in water tank, toilet tank, and plumbing. This may also be accompanied by a foul odor.

Treatment Method

Considerations

Shock Chlorination – consider following with continuous chlorination

Chlorine products must be suitable for drinking water. Method requires extended periods of contact time for adequate treatment.

 

Organic Iron and Tannins

Symptoms
Water containing organic iron ranges from yellow to brownish color, but may also appear colorless. Tannins stain water with a tea-like color.

Treatment Method

Considerations

Water Softener

Must treat water for organics. Check for corrosive properties. System must be airtight

Manganese Greensand/Filtration

Treat for organics first. Adequate pressure

Ozonation

Cost

Turbidity can be removed by installing a water softener.