Manganese is a commonly occurring natural mineral in the earth or soil. It’s essential for human health, but consuming excess manganese can present a number of problems, both health-related and aesthetics-wise.
While manganese can be found in city water, it’s most commonly found in wells. If manganese occurs in higher levels than 0.05 mg/L, it may cause residential water to take on an orange, black or brown appearance and a bitter taste. This mineral may be a nuisance, leaving deposits in your water-based appliances and on your laundry, and may create a film on top of stagnant toilet water. It may also have a metallic smell in cases of elevated levels.
Luckily, there are numerous simple and effective means of removing manganese from your water today. In this guide, I’ll be sharing everything you need to know about this metal – what it is, why it’s required to remove it, and the best ways to filter it out of your water.
Table of Contents
💡 What is Manganese?
Manganese is a mineral that occurs in rocks, soil and sediment. This beneficial metal is present in a number of fruits, vegetables and grains. While it’s an important nutrient in the human diet, it’s considered unhealthy when consumed in high levels in water.
Manganese is often found in deep water wells, with some wells with up to 3 PPM of the mineral. It doesn’t take much manganese – usually approximately 0.05 PPM – to cause staining and damage appliances around your home. It’s common to find manganese and iron together, and these metals often combine to form deep brown staining and other negative effects in your home.
You’ll usually see evidence of this metal predominantly in your dishwasher, as many detergents raise water’s pH, which allows manganese to take on a solid form. In addition, you may be able to see the metal floating on the surface of your toilet water, giving it a brown-ish tinge.
There are two common forms of this metal – manganous manganese (the most common form) and manganic manganese. Manganous manganese is manganese in a completely dissolved form. This type of manganese requires precipitation – i.e. conversion into solid form – before it can be filtered out of water.
Solid manganese that has been allowed to precipitate is known as manganic manganese. This precipitate metal can be removed by a water filter, but water softeners are best at removing manganous manganese.
🩺 Health Risks Associated with Manganese
There’s insufficient evidence to suggest that drinking a low concentration of manganese in water will have an effect on your health. But if you have enough of the metal in your water to leave stains (0.05 PPM or more), you may experience some health problems.
Drinking a high concentration of manganese for an extended period of time may cause neurological problems such as issues with memory, motor skills and attention. Children and babies are especially at risk, and may develop related problems with learning and behavior due to drinking water with a high concentration of manganese.
🤔 How Does Manganese Get Into Well Water?
Because manganese is naturally occurring in surface water, it’ll usually get into wells through surface runoff and rainwater sources. When water seeps through soils containing this metal, it picks it up, which may result in it entering the well through the aquifer.
Iron and manganese often occur in water together. These metals are more common in deeper wells, as water usually has a longer contact with rocks containing iron and manganese. Iron and manganese can both be found in groundwater, but often, there will be less manganese than iron. For that reason, if your water supply contains iron, it’s highly likely that it’ll also contain manganese.
Human activity may also play a part in manganese in drinking water sources. It’s thought that emissions from traffic may be linked to a higher concentration of the metal in the air and ground. If you live in a coal-mining region, you may also have more iron and manganese occurring in your soils from both surface mining and deep mining activities.
What is a Safe Level of Manganese in Drinking Water?
Manganese in its dissolved state is a healthy and normal part of the human diet in small amounts, being found in a number of foods as well as our water supplies. But if residential or well water contains so much manganese that it takes on a metallic taste or a black or brown color, it may pose some potential concerns to health.
While levels of manganese over 0.05 PPM may affect tap water quality, resulting in stains and other damage to your home’s fixtures, the safe level of this metal in drinking water is nearly ten times this.
The US Environmental Protection Agency (EPA) has set standards advising that a person must not be exposed to more than 0.3 mg/L manganese in drinking water throughout their lifetime. According to the standards, this level of manganese should prevent neurological damage throughout a person’s life. It’s especially important that little children under the age of three must not drink tap water with manganese quantities that exceed 0.3 mg/L of manganese, particularly if they’re formula-fed.
Drinking from a water supply with a bitter metallic taste indicates high manganese levels present, and you must not consume water with more than 0.3 mg/L of manganese – although you can shower and bathe in this water without risking your health.
How Can I Prevent Manganese Getting Into My Well Water?
Because manganese largely comes from natural sources, it’s difficult to stop it from getting into your well water supply. Remember that iron and manganese are often present together, and may occur naturally in higher quantities in some states than in others. In addition, coal mining regions are particularly prone to high iron and manganese levels, as are areas with heavy traffic on the roads.
It’s probably not practical to move to an entirely new state to say goodbye to your iron and manganese-related problems. But if you’re noticing that unusually high quantities of iron & manganese are entering into your raw water, the design of your well may be an issue. Check to make sure your well is structurally sound, with no cracks or gaps in the seals, pump or aquifer. Remember also that a deep well is more likely to collect more manganese from water, so if you’re planning to build a new well, it may be better to build a shallow one.
Ultimately, preventing manganese from getting into your drinking water is often more fuss than it’s worth – perhaps even impossible. Using water treatment options to remove iron & manganese tends to be a much more practical solution.
🧪 How to Test for Manganese in Well Water
The best testing method for a manganese-related problem is to arrange to get your water tested by an accredited laboratory. In this situation, you’ll usually have to collect a sample of well water from your home’s point of entry and send it off to a laboratory, where extensive tests will determine your water quality.
The advantages of laboratory testing are obvious – you can learn exactly what’s in your water, and to what level, so you can say for certain whether you’re at risk from your water’s contamination levels or not. It’s advised to get your well professionally tested for chloride, sulfur, iron, manganese and corrosion once every three years.
Remember, there are two forms of manganese, each requiring different treatment systems for removal. A laboratory can indicate which forms of manganese are most predominant in your water, helping you to select the best water softening or filtration methods for manganese removal.
You can also test your raw water at home for manganese. While this isn’t the most thorough option, and will only indicate a presence of manganese rather than tell you exactly how much your water contains, it’s a useful test to carry out between laboratory testing.
If you want to make sure your water’s manganese levels don’t randomly spike, or you just want to check that one of your water treatment systems is removing manganese to the expected effectiveness, using a DIY kit is a great option.
Again, the same as if you were to get your water tested by a lab, for this DIY method, you’d be required to take a recent sample of water at your home’s point of entry. You’d then dip one of the test’s strips into the water and leave it submerged for several seconds, before removing it and waiting for it to change color. The color of the strip would indicate whether your water contains manganese.
✅ How to Remove Manganese in Water
How to remove manganese from water? Manganese is generally a fairly difficult mineral to remove from water because there are several things that have effects on manganese’s state, including water’s pH and the presence of other minerals. However, some of the various methods of manganese removal from well water include the following:
You probably don’t immediately think of water softening systems when you imagine manganese removal from water, but whole-home water softeners can be effective in removing iron and manganese as well as hardness minerals. This type of water treatment is largely used to filter out calcium and magnesium hard water minerals using ion exchange. During this process, calcium and magnesium are attracted to a resin bed, which releases sodium ions into the water to take their place.
A water softener can use the same process for iron and manganese removal. When sodium is released into the water, manganese and iron stick to the media bed. The water softener will backwash its tanks periodically when the media is at capacity, which flushes the media and replaces the sodium ions, thus allowing the process to take place over and over again.
Water softeners, installed to effectively provide hardness reduction in your whole home, are efficient in removing small amounts of manganese if water hardness is between 3 and 20 GPG (grains per gallon).
For a water softener to be worth your money, certain conditions need to be in place:
- Your water needs to have a pH of greater than 6.7
- Your water source needs to contain a low amount of dissolved oxygen
- And preferably, your iron concentrations should be less than 5 mg/L
In different circumstances, a water softener may be ineffective at removing manganese, and it won’t be worth investing in you’re purely looking for manganese removal.
If conditions are right, a water softener can be highly effective in tackling a manganese problem, although you should keep in mind that an increase in manganese and iron in their oxidized states may do more damage than good to a water softener resin.
It’s important that your raw water is unable to come into contact with a strong oxidizing agent (such as chlorine or the air) before it passes into the water softener. This could damage the softener resin bed during the ion exchange process, and it’s significant to know that much more frequent backwashing per week is necessary, as the resin reaches capacity more often. Thus, if oxidized iron and/or manganese that have undergone precipitation are present within the raw water, filtration should be used for removal.
Air Injection Oxidation
Air injection, otherwise known as aeration, is another recommended water treatment method for removing manganese, iron and hydrogen sulfide issues. In this form of treatment, a filtering resin isn’t necessary; instead, it treats water with an injected pocket of air to ensure a high concentration of manganese is removed.
In this type of filtration system, water will feed into a tank, which has a pocket of air at the top. While water is in this aeration tank, the dissolved metals will change state, becoming oxidized. They then stick to the media bed, and can be removed from the tank with backwashing. The tank is replenished with a fresh air pocket during regeneration. Maintenance such as regeneration will increase due to an increase of metals in the water – the more manganese, the more frequent maintenance you’ll require.
An air injection filtration system is an effective option for a high concentration of dissolved metals, being capable of filtering iron, sulfur and manganese. It comes at a relatively low cost, too, so it’s ideal if you have a reduced budget.
Oxidation media makes it possible to oxidize and filter manganese at the same time. Manganese greensand is a popular material used in the design of this filter media, but birm may also be used for treating water in the same way.
In manganese greensand filters, the filter media is treated with a coating of something called potassium permanganate, which is used to oxidize iron and manganese, trapping them in the filter media before flushing them out of the system. Ozone and hydrogen peroxide may also be used.
Looking after a manganese greensand filter takes some effort. You’ll need to carry out maintenance in the form of regenerating the oxidation filtration media with potassium permanganate or ozone, and backwashing the system to remove manganese from the media and freeing it up for the next use.
Manganese greensand filters are a fantastic drinking water treatment option for water with moderate amounts of manganese in both states. If you have manganese or iron concentrations of around 2.5 to 10 mg/ L, this oxidation filtration solution will work well for you. Just keep in mind that the higher the concentration of metals in your drinking water, the more frequently you’ll have to backwash this system.
A birm filter works similarly to remove manganese, but has an advantage: it requires no regeneration. This is because the type of media in a birm system uses oxygen from the water itself to oxidize the impurities. Because of this, water needs to have a relatively high amount of dissolved oxygen, and you need a high pH of at least 7.5. You’ll still have to backwash a birm filter to remove the solid particles of metal.
Finally, reverse osmosis is one of the most popular drinking water treatment options for the removal of a whole host of impurities, and is usually thorough enough to be capable of removing just about anything.
There are several filter stages in a reverse osmosis purification system that ensure water is treated effectively. These filter stages include sediment filter cartridge membranes, activated carbon filter cartridge membranes, and post-filter membranes. But the main star of the show, which you’ll find in all reverse osmosis systems, is the semi-permeable membrane. RO membranes contain small pores that act as a sieve – when water is pushed against the membrane, only very small water particles can pass through, leaving the lingering contaminants in the chamber, where they’re flushed away with wastewater.
Reverse osmosis filtration systems are an overall effective water treatment option for a high concentration of both dissolved iron removal and dissolved manganese removal, especially if you like the idea of a system that can also offer reduction and purification of a whole host of additional contaminants, like lead, hydrogen sulfide, aesthetic impurities, chemicals, bacteria, arsenic and VOCs. You don’t need to backwash RO water systems, but in this case, the filter membranes must be changed once every six months to one year, and the semi-permeable membranes must be replaced after every 2 years or so. Membranes and filters are widely available to buy online.
You can install an RO unit at your home’s point of entry. This system requires a relatively high pressure to be efficient, so it’s recommended to purchase a pressure pump if your water pressure is currently lower than advised. It can cost a lot of money, but many people think it’s worth it for removing manganese from water in the long run.
❔ Frequently Asked Questions
Does Boiling Water Remove Manganese?
No, and actually, boiling water for too long will just evaporate some of the water and cause manganese molecules and other metals and elements to become more concentrated. The best way to get these contaminants removed is to use one of the filters or softeners mentioned above.
Can Chemical Treatment Remove Manganese?
Yes. You can use a chemical such as chlorine to treat water with a high manganese content. Chlorine is a strong, effective oxidizer, so this chemical works in a similar way to an air injection tank that uses oxygen from the air. Chlorine oxidizing systems typically use a feed pump to send measured concentrations of chlorine into water in a tank. Usually, a contact time of around 20 minutes is required for water to be effectively oxidized by the added chlorine. This treatment solution, using added chemicals, doesn’t require backwashing.
Can Catalytic Carbon Remove Manganese?
Yes, catalytic carbon is one of the most, effective methods of removing manganese, but it’s advised that you use it after an oxidizing process, such as aeration, for efficiency. Catalytic carbon can also reduce or remove aesthetic contaminants like chlorine.