This is the first of a 3-part series on “How to Remove Iron, Manganese, And Odor From Well Water.” The second and third parts discuss easy and effective ways to remove iron, manganese, and odors from your well water, without having to spend a lot of money.
Iron and Manganese
The first step to learn how to remove iron, manganese, and odor from well water is to understand a little about where iron comes from and the types of iron found in well water. Iron is one of the earth’s most plentiful resources, making up at least five percent of the earth’s crust. In well water you find iron in a dissolved state so water may appear clear when first drawn from the tap.
Iron, one of the earth’s most plentiful resources, makes up at least five percent of the earth’s crust. In well water, iron is usually found in a dissolved state and may appear clear when first drawn from the tap.
The maximum level of iron recommended in water is 0.3 mg/L. This is same as saying 0.3 Parts Per Million or PPM. When the level of iron in water exceeds the 0.3 mg/l limit, the water may have a red, brown, or yellow color and stain laundry and fixtures.
Manganese is another metal that leaves stains. Instead of rust stains like iron, it leaves a brown, or tea color stains on fixtures, dishes, and laundry. It also has a bitter taste which some describe as asphalt or petroleum taste.
Odor and Taste
The water may also have a metallic taste and an offensive odor. Water system piping and fixtures can become restricted or clogged. Appliances such as water heaters, dishwashers and washing machines, can be plugged with rust and sediment.
Iron and manganese also give well water a disagreeable metallic taste. When the iron combines with tea, coffee, and other beverages, it produces an inky, black appearance and a rusty, bad taste.
Questions to Ask When Choosing an Iron Filter:
- What type of iron do I have in my water system?
- What is my well water chemistry? Do I have manganese, hydrogen sulfide odor, iron bacteria, or tannin in my water..or just iron? What is the pH (acid or alkaline)?
- What is the source of the iron and/or odor? Is it only from the well water or is it also from corroding iron pipes or water heater?
- What is the flow rate I have available in gallons per minute from my well pump or booster pump, to adequately backwash the iron filter I choose?
1. There are four main types of iron or conditions in which iron is found in well water:
- Soluble “Clear Water” Iron
- Insoluble Oxidized “Red Water” Iron
- Organic Iron
- Iron Bacteria
Clear Water Iron
Water may be clear when first drawn from a hose bib or faucet, but then turn rusty later. This is iron that is dissolved in the water but later will turn to rust once it is exposed to air.
The exposure to air can happen anywhere or anytime, such as in the toilet, washing machine, or bath. To determine the type of iron, fill a clean white 5-gallon bucket with water. If the water is clear without a tint or color, you have primarily ferrous iron.
Use an oxidizing iron filter such as Pro-OX or other manganese dioxide iron filters to turn the dissolved iron to rust form, where it is then filtered out by the iron filter. Periodic backwash keeps the Pro-OX filter media clean. Often these iron filters use aeration to enhance the oxidizing ability of the filter media.
Red Water Iron
Also known as ferric iron (rust) this is iron that has already been exposed to some oxidation and is no longer dissolved in the water. Rarely does water contain only ferric iron. Often part or some of the water is oxidized and the rest of the water has clear water iron.
As above, also use an oxidizing iron filter which removes both clear water iron and red water iron. If the water was from a storage tank or lake where 100% of the iron was ferric iron (rust) then a sand filter or filter cartridge would remove it.
Some waters contain high levels of tannins which can enter the well water from the surface. Materials such as organic leaves, grasses and other plant materials cause Tannins. These organic compounds can bind with iron.
Use chlorine bleach, hydrogen peroxide, or ozone gas feed ahead of the iron filter with sufficient contact time by using a retention tank. After filtering with manganese dioxide iron filter, follow with activated carbon filter. In some cases if the iron is colloidal (microscopic particles that cannot be easily settled out or filtered) then alum or polymer coagulant feed may be needed to clump the particles into larger particles that can be filtered.
Iron bacteria is a general term used to describe various species of bacteria that use iron to live and grow. Iron becomes part of their cell walls and the end result is a slimy stringy growth that can be seen in toilet flush tanks. The stringy growths can also line pipes and build up in water tanks, fixtures, and appliances.
Use chlorine bleach feed to disinfect the water and kill the iron bacteria, followed by Pro-OX iron filter. A carbon filter can be used after the iron filter to remove any residual chlorine. Chlorine bleach is much more effective at eliminating iron bacteria than hydrogen peroxide however, ozone is another option that is effective as well.
2. Use Home Tests to Find Out What’s In Your Water
The best way to find out is to do a water test of the water right from the well before it enters the house. If this is not possible, then run the water for 5 to 10 minutes so you know the water is coming right from the well.
A water test is important to know which type of iron filter to use and if your water is acidic or not.
A water test will tell you how much iron you have. This knowledge helps you to choose the type of approach or system you should use to treat it.
Tests should include alkalinity, hardness, hydrogen sulfide, iron, manganese, pH, and total dissolved solids. If the water has a tea color to it or has a yellowish clear color to it, then a tannin test is recommended as well.
You should always include a pH test, which indicates if the water is acidic or alkaline. The ideal pH for iron filters to work properly is between 7.0 and 8.0, which is considered neutral and not acidic.
For health-related concerns include a test for total coliform, e-coli (fecal coliform), lead, and nitrate. A complete mineral, metals and bacteriological tests from a State certified laboratory is recommended; especially if infants and children will be drinking the water.
When the source of your water is a public water system and you experience iron-related problems, it is important to contact your water company to determine whether the red water is from the public system or from the home’s plumbing or piping.
3. Do a Quick Physical Inspection of Your Water and Pipes
If you are experiencing iron or rust staining, it is important to determine the source, whether from the well water or perhaps from corroding pipes or fixtures.
Usually, the source of the iron is from the well water itself, as iron naturally occurs in many ground waters.
In some cases, the staining may be caused by old galvanized iron piping or fixtures which have been corroded, making the water rusty.
Run a hose bib or tap as close to the well as possible and fill a white 5-gallon bucket or other container and check the color of the water, noting if there is any sediment present.
Notice if there are odors. If you smell a “rotten egg” odor, this is hydrogen sulfide gas coming right from your well water.
Manganese can make your water smell like oil or asphalt. In case your water smells like cucumber or sewage, it is usually due to iron and/or sulfur bacteria.
Run the hot water from each tap and notice if there is an odor in the hot water that is not in the cold water. This indicates a problem with the water heater.
Iron and sulfur bacteria could interact with the anode rod in water heaters. This interaction may result in hydrogen sulfide gas only in the hot water. To solve this, change the anode rod to an aluminum rod.
Even if there’s no odor in the cold water but the hot water smells like rotten eggs, then you can also add a pint of store-bought hydrogen peroxide to the water heater and let it sit for 4 – 6 hours. This will often kill the odor for weeks or months. There are special filter strainers that make it easy to add peroxide to the water without having to take apart the piping.
4. Check Your Well Pump Flow Rate
Flow rate is defined as simply how many gallons in one minute can be pumped from the well. This is determined generally by the size of your well pump. It is also affected by the capacity of your well.
For example, if your well pump can fill a 5-gallon bucket in 60 seconds direct from the well, you can consider you have 5 Gallons Per Minute, or 5 GPM.
Most homeowners have a standard single-speed submersible pump with a pressure tank on their private well. This test is for this standard type of pump and pressure tank. If you have a ‘constant pressure’ or variable-speed pump, this test as described below won’t work.
A good flow rate is required in order to be able to backwash the filter systems properly. An adequate flow rate is also required in order to provide good water pressure to the home.
Count the gallons “drawn down” from the pressure tank and the time between the cut-in and cut-off cycle of the well pump. This is known as pressure tank ‘draw down’.
Easy Steps To Take to Find Our Your Well Pump Flow Rate:
- First, allow the well pump to build up to full pressure by running water in the home or from a hose bib or faucet until you hear the well pump kick in or pressure switch points click.
- Close faucet and make sure no water is being used in the home. Well pump will build up pressure for a few minutes and then pressure switch will shut off well pump.
- Next, open a hose bib (also referred to as a ‘spigot’ or ‘faucet’) anywhere near or after the pressure tank.
- Run the water into a 5 gallon bucket, noting how many gallons you collect. If bucket fills up, dump out water and keep measuring and filling.
- Measure the number of gallons drawn down from the pressure tank until the well pump turns on.
- When you hear the pump turn on, immediately close the hose bib.
- Time the period in seconds it takes for the well pump to build back up to pressure that is, between the cut- in and cut- out of the pressure switch. The pressure switch turns on the pump at a lower pressure and turns off the pump when it reaches a higher pressure.
- The formula for determining the flow rate is: gallons drawn down (that were measured above), divided by the seconds required for recovery, then multiplied by 60:
- (Gallons / Seconds) x 60 = Gallons per Minute (GPM) flow rate..
- For example, if 20 gallons are drawn down and it takes 120 seconds to build pressure back up, then: 20 divided by 120 = .166. Then multiply .166 x 60 = 10 gallons per minute flow rate.
- So you have 10 GPM flow rate.
The next 2 posts will explain the step by step procedure on how to remove iron, manganese, and odor from wellwater. You can read the next step here after downloading your iron treatment guide.
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