With more than 30 years’ experience in the residential and commercial water treatment space, Mark Nelson is a Class 1 Drinking-Water Operator and a CBWA (Canadian Bottled Water Association) Certified Plant Operator. As founder and president of Nelson Water in Ottawa, Mark focuses on dealing with challenging water treatment system designs for problem water. He also heads the largest water bottling plant in the city of Ottawa with a delivery network throughout the Valley.
If you’ve ever needed to lift the lid on your toilet tank and discovered that the water is black or seen black stains, it can be a real shock. If you’ve ever seen dark or black stains inside your shower stall or dishwasher, it can be equally surprising. In both cases, the root cause is probably the same; the source of these issues usually indicates the presence of elevated levels of manganese. These types of stains are unsightly, they can be hard to remove, and they usually return quickly. In this article, we will take a closer look at manganese, examine how it affects your home, and offer a solution to get rid of it for good.
What is Manganese?
Manganese is a naturally occurring mineral that is an essential nutrient for our health when it’s present in food. When manganese is present in your water in high concentrations, it can create dark or black stains. This can alter the color of your drinking water, stain your plumbing fixtures and even cause stains on your laundry. Drinking water that contains too much manganese will not be a threat to your health in the short term, but exposure over long periods may be a risk to the nervous system. Although more research is needed on the health risks of manganese Health Canada has offered guidelines in the values that should be consumed. In the U.S., the EPA has warned that consumption of high levels of manganese is a long-term health risk. Manganese is often found in hard water; the mineral content can create scale, which narrows pipes and damages plumbing systems.
Why is Manganese in the Water Supply?
Manganese is one of the most common metals found in soil and water. As we mentioned earlier, it’s an essential nutrient found in many foods, such as beans, nuts, and oatmeal. When eaten in smaller quantities, manganese is good for us, and it supports our bodies as part of a healthy diet. The manganese found in water is less suitable as a nutrient source because it isn’t taken up by the body in the same way.
So, most locations have a certain level of manganese that occurs naturally in their water. But, certain areas have elevated levels of manganese due to a number of geographic factors. Areas with soil rich in manganese add the mineral to the water during storms and runoff. Many people are unaware that water is a solvent, it can dissolve many materials, and it adds them to its makeup. Water treatment plants do not remove manganese from public water, and this is how it reaches our homes. Aside from the staining, you may notice that your water has an unpleasant metallic or earthy taste.
How Does Manganese Affect My Home?
It’s important to repeat that ingesting manganese over a short period of time isn’t likely to cause a health problem. But, research is ongoing, and it’s advisable to avoid drinking or cooking with it at all. That being said, most people would not be able to drink water that contains high concentrations of manganese. The waster tastes, looks, and smells bad, and it’s doubtful that anyone would enjoy drinking it. We’ve already mentioned the unsightly black stains in the toilet and on other plumbing fixtures. But, high levels of manganese can cause damage in areas that you cannot see. Your water using appliances, such as your water heater, dishwasher, washer, and water softener, are all at risk. The damage caused by manganese can lead to more frequent repairs and even shorten the expected lifespan. This is equally true with your plumbing pipes, which will accumulate a layer of scale on the inner surface. This will lower the water pressure and eventually break the pipe leading to an expensive repair bill. If you have high levels of manganese, it can be expensive in the medium to long term.
Can Manganese be Removed from My Water Supply?
Yes, but it can be a challenge because the manganese removal is dependent on the oxidation state, other minerals, and the pH level of the water. When manganese is present in high concentrations, it’s often accompanied by hydrogen sulfide and iron. So, it can be hard to remove manganese, but it’s important to consult a local water treatment specialist. Many homeowners believe that a standard water softener can remove manganese and even iron. But, this isn’t the case; manganese can damage a water softener leading to an expensive repair bill.
How Does Manganese Damage a Water Softener?
The most effective type of water softener on the market is an ion-exchange system. This uses a resin bed where the ion-exchange process takes place. The minerals that cause hard water, including calcium and magnesium, are exchanged with benign sodium (salt) ions to make the water softer. The hard water mineral ions are left on the surface of the resin media until a regeneration cycle when they are rinsed clean. But, if you have high concentrations of contaminants, it can foul the resin media and even cause damage to the resin bed. The resin media will require more frequent backwashing to get clean, and this will place additional strain on the unit. Whenever equipment is operated under stress, it tends to fail, and the expected lifespan may be reduced.
What is the Solution?
It’s essential to get a water test, and based on those results, an iron filter may be the best treatment option. This is because manganese and iron are pretty similar chemically; this can be an effective treatment method. Another solution may be a zeolite filtration media that can remove manganese, iron and restore pH balance to your water supply. For your drinking water, you may be considering a reverse osmosis (RO) system, and this is effective. But, a RO system relies on a semi-permeable membrane which will be clogged up with manganese quickly.
If you want to remove manganese from your water, contact your local water treatment specialist today.