How to Test and Remove Manganese in Well Water: A Complete Guide

You might have encountered manganese in well water if you rely on a well for your home’s water supply. This naturally occurring mineral is an essential trace mineral commonly found in groundwater and, while essential in small amounts, can cause significant problems when its levels are too high.

High levels of manganese can cause brown or tea-colored stains on fixtures, appliances, and laundry. It can also impart a bitter taste to water and cause odors.

Understanding and managing manganese is crucial for ensuring the health of your family and the quality of your home’s water, from stained laundry and plumbing fixtures to potential health risks.

In this comprehensive guide, we’ll explore why it occurs in well water, what it looks like, the effects it can have, and practical solutions for testing and treating it.

Why is Manganese Found in Well Water?

Manganese is a natural component found in rocks, soil, and sediments. Over time, it leaches into groundwater as rocks and soil break down. While manganese is present in almost all water sources, its concentration in well water depends on several factors.

Natural Sources

Groundwater flows through mineral-rich geological formations, picking up trace amounts of manganese. Regions with organic-rich soils and shallow aquifers, mainly near rivers or wetlands, tend to have higher manganese concentrations. The lack of oxygen in these areas—known as anoxic conditions—facilitates the dissolution of manganese into water. Manganese is also commonly found in surface water.

Human Activities

Human activity can exacerbate the problem. For example, agricultural practices, such as using nitrogen-based fertilizers, can increase groundwater acidity.

This acidic environment promotes the mobilization of manganese, making it more likely to dissolve into well water. Areas with poorly buffered soils, like parts of the northeastern United States, are particularly susceptible to this issue and other potential contaminants.

What Does Manganese in Well Water Look Like?

Detecting manganese in water isn’t always straightforward. While you may notice some signs, lab testing or using a home manganese test kit is the only way to confirm its presence and concentration. Boiling water does not remove manganese and can increase its concentration if boiled too long.

Physical Signs

• Staining: One of the most common indicators of manganese in well water is staining. Manganese can leave black or dark brown stains on laundry, sinks, tubs, and plumbing fixtures. These stains are often mistaken for dirt or mold but are deposits from water.
• Sediment or Discoloration: Water with high manganese levels may appear cloudy or have black particles. These particles are often dissolved metals, including manganese, which can also give the water a slimy texture in severe cases.
• Taste and Odor: Manganese can give water a metallic or bitter taste and may contribute to unpleasant odors.

Testing for Manganese

While physical signs can suggest the presence of manganese, having your water tested is the only way to determine its concentration accurately. While manganese testing kits are available for home use, the best option is to send a sample to a certified lab for precise results. Testing will also reveal other water quality issues, such as pH levels and iron and nitrate concentrations, that may affect treatment options.

Effects of Manganese in Well Water

Aesthetic and Practical Issues

• Laundry and Plumbing: Stains on clothing and fixtures are unsightly and can be difficult or impossible to remove. Over time, manganese deposits can build up inside plumbing systems, reducing water flow and damaging appliances like water heaters. The aesthetic objective for manganese levels is to ensure that water remains visually appealing.
• Clogged Pipes: Manganese particles can accumulate in pipes, causing blockages that reduce water pressure and require costly repairs.

Health Impacts

While manganese is an essential nutrient in small amounts, excessive exposure through drinking water can be harmful, especially for vulnerable populations like infants and children.

• Neurological Effects: Prolonged exposure to high manganese levels has been linked to adverse neurological effects, including memory issues, learning difficulties, and impaired motor skills.
• EPA Guidelines: The U.S. Environmental Protection Agency (EPA) recommends manganese concentrations below 0.05 mg/L for aesthetic concerns and under 0.3 mg/L for health reasons. Approximately 2.6 million Americans consume groundwater with manganese levels exceeding these thresholds.

Step 1: Test Your Water

Before implementing any treatment system, testing your water and manganese levels is essential if the water contains manganese at concentrations over 0.05 mg/L (sometimes expressed in parts per billion or 50 u/L.

Comprehensive testing will provide you with the manganese concentration and reveal any additional water quality issues that must be addressed. Regular testing is recommended every 1-2 years or after environmental events like flooding.

Step 2: Treatment Methods for Manganese in Well Water

• Oxidizing Filters: Oxidizing filters use media, such as Pro-OX manganese dioxide or Greensand filter media, to convert dissolved manganese into solid particles. These particles are then trapped and filtered out. They are best for moderate manganese levels up to 5.0 mg/L. They require periodic backwashing to maintain performance. Additionally, oxidizing filters require frequent regeneration with a potassium permanganate solution to maintain their effectiveness in oxidizing and filtering metals from water.
• Chemical Oxidation Combined with Filtration: This method involves adding an oxidant, such as chlorine, ozone, or potassium permanganate, to the water. The oxidant reacts with manganese, converting it into a solid form that filtration can remove. It is effective for higher manganese concentrations or water containing both iron and manganese and works well when combined with an oxidizing filter.
• Ion Exchange Water Softeners: Water softeners designed to remove hardness minerals can also reduce low levels of manganese up to 0.2 mg/L. However, they are not recommended for water with high manganese concentrations, as excessive manganese can foul the resin.
• Aeration: Aeration systems introduce air into the water, oxidizing manganese to filter it out. They are often used in combination with other filtration systems for more effective removal.

The Role of pH in Manganese Concentration Removal

The pH level of your water plays a critical role in the effectiveness of manganese removal methods. Manganese is more soluble in acidic water, making it harder to filter out in systems with a pH below 6.5.

If the well water pH is less than 6.9, raising the pH through aeration or adding a calcite neutralizer or soda ash feeder before the manganese filtration system is critical. The ideal pH is between 7 and 8.5 for most applications. Sufficient dissolved oxygen levels are crucial for effective manganese removal.

Step 3: Routine Maintenance

Regularly check and maintain your treatment system to ensure it’s functioning correctly. Replace filters and media as needed based on the manufacturer’s recommendations and your water’s manganese levels. Maintaining the softener resin is crucial for effective manganese removal, as oxidized minerals can foul the resin and degrade its performance.

How to Prevent Future Problems

Preventing manganese contamination in well water involves proactive measures to protect your water source and treatment system.

• Proper Well Construction: Ensure your well is constructed and located to minimize contamination risks. Avoid placing wells near agricultural runoff or septic systems.
• Annual Inspections: Schedule regular inspections of your well and treatment system to identify and address potential issues early.
• Water Testing: Regular testing is key to monitoring changes in water quality and ensuring your treatment system is performing as expected.

The Importance of Properly Sizing Your Manganese Removal Filter System

Ensuring your filtration system is appropriately sized is crucial for effective water treatment. Factors such as the number of bathrooms, household water usage, and flow rates determine the optimal filter size.

For instance, the Pro-OX 7500 Iron Filter is available in various sizes to accommodate different needs. Selecting the correct size ensures the system can handle your water demand without compromising performance. Additionally, proper backwash flow rates are essential for maintaining the efficiency of the Pro-OX media.

Each filter size requires a specific backwash flow rate to cleanse the media and prevent clogging effectively. Therefore, understanding your household’s water usage and flow requirements is vital for choosing a filter system that provides reliable manganese removal and long-term performance. Point-of-entry treatment systems are particularly important for effective manganese removal as they address contaminants at the water's entry point, ensuring better overall water quality throughout the home.

Helpful Links

If you want to dive deeper into this topic, the following resources from trusted organizations and government agencies provide valuable information:

• • U.S. Geological Survey (USGS): Manganese in Groundwater – A detailed overview of how it occurs in groundwater and its potential effects on water quality.
  • Centers for Disease Control and Prevention (CDC): Manganese and Your Health – An informative page discussing the health impacts of manganese exposure and safety guidelines.
  • Environmental Protection Agency (EPA): Secondary Drinking Water Standards – Learn about the EPA’s recommendations for manganese levels in drinking water and other secondary water quality standards.
  • National Groundwater Association (NGWA): Understanding Groundwater Contaminants – Provides insights into contamination and its impact on well water systems.