How to Filter Arsenic from Water

Arsenic is a toxic element that can be found in groundwater, posing a threat to human health when present in drinking water. In this article, we will discuss the most effective methods for filtering arsenic out of water and help you choose the best solution for your needs.

Why Remove Arsenic?

Arsenic in drinking water can cause several problems, including:

  • Health risks: Long-term exposure to arsenic can lead to various health issues, such as skin, lung, bladder, and kidney cancers, as well as cardiovascular disease.
  • Regulatory standards: The EPA sets a maximum contaminant level (MCL) of 10 parts per billion (ppb) for arsenic in drinking water to protect public health.

Identifying Arsenic in Your Water


Arsenic is tasteless, odorless, and colorless, making it difficult to detect without proper testing.


To accurately determine the presence and concentration of arsenic in your water, consider the following testing methods:

  • At-home test kits: Affordable and easy-to-use kits that provide results for arsenic levels, but may not be as accurate as laboratory testing.
  • Professional laboratory testing: For the most accurate results, send a water sample to a certified laboratory for a comprehensive analysis.

Maintenance and Replacement


Regular maintenance and filter replacement are essential for maintaining the effectiveness of any water filtration system. Neglecting these tasks can result in decreased performance and reduced water quality.


Choosing the Right System for Your Needs

Factors to consider

When selecting the best arsenic filtration system, consider factors such as:

  • Budget
  • Space constraints
  • Ease of installation
  • Maintenance requirements
  • Specific water quality issues


A side-by-side comparison of different arsenic filtration methods, highlighting their pros and cons, can help you make an informed decision. Consider factors such as effectiveness, cost, and maintenance requirements when comparing options.

MethodTimeCostEffectivenessInstallation & MaintenanceAdditional Benefits
Activated AluminaImmediateModerateUp to 95%ModerateCan also treat other contaminants like fluoride
Reverse OsmosisImmediateModerate to HighUp to 99%ModerateRemoves a wide range of contaminants, including heavy metals and minerals
Ion ExchangeImmediateModerate to HighUp to 90%ModerateRemoves hardness-causing minerals like calcium and magnesium
Adsorptive MediaImmediateModerateUp to 95%ModerateCan also remove other contaminants like lead and chromium

This table compares the various methods for removing arsenic from water, taking into account factors such as time, cost, effectiveness, installation and maintenance requirements, and additional benefits. Note that the values provided are general estimates and may vary depending on specific products or situations.

Activated Alumina

Activated alumina is a popular method for removing arsenic from water.

  • Function: This process involves adsorption, wherein arsenic molecules adhere to the surface of activated alumina granules.
  • Types: Available as point-of-use or point-of-entry systems.
  • Effectiveness: Can remove up to 95% of arsenic.

Reverse Osmosis Systems

Reverse osmosis (RO) systems are highly effective for filtering arsenic from water.

  • Function: RO systems force water through a semi-permeable membrane, trapping contaminants like arsenic.
  • Types: Primarily available as under-sink systems.
  • Effectiveness: Can remove up to 99% of arsenic.

Ion Exchange

Ion exchange systems, also known as water softeners, can effectively remove arsenic.

  • Function: These systems replace arsenic ions with sodium ions, eliminating arsenic from the water.
  • Types: Available as whole-house systems.
  • Effectiveness: Can remove up to 90% of arsenic.
  • Additional benefits: Can also remove hardness-causing minerals like calcium and magnesium.

Adsorptive Media

Adsorptive media filters can also filter arsenic out of water.

  • Function: These filters use a specialized media that attracts and binds arsenic molecules, removing them from the water.
  • Types: Available as cartridge filters or backwashing systems.
  • Effectiveness: Can remove up to 95% of arsenic.

DIY Solutions


While DIY solutions may not be as effective as professionally installed systems, some options can still provide noticeable improvements in water quality:

  • Pitcher with built-in filter: Some water filter pitchers are designed to remove arsenic and other contaminants. However, their effectiveness may be limited compared to other methods.
  • Homemade adsorptive filter: Create a simple adsorptive filter using a container, iron-based adsorptive media, and a porous cloth or mesh material. Keep in mind that this method may not be as effective as a professionally designed filter, and the media will need to be replaced periodically.

Always keep in mind that DIY solutions are not as reliable as professional filtration systems and may not provide the same level of protection against arsenic exposure.


Several methods can effectively filter arsenic out of water, including activated alumina, reverse osmosis systems, ion exchange systems, and adsorptive media filters. The best method for you will depend on your specific needs, budget, and preferences. By choosing the right solution, you can protect your health and ensure your drinking water meets regulatory standards.

Frequently Asked Questions (FAQ)

Q1: How does arsenic get into drinking water?

Arsenic can enter drinking water through natural sources, such as the erosion of rocks and minerals in the ground, or through human activities, including industrial processes, agricultural runoff, and improper waste disposal.

Q2: What are the health effects of arsenic exposure?

Long-term exposure to arsenic in drinking water can lead to a variety of health issues, including skin, lung, bladder, and kidney cancers, as well as cardiovascular disease, diabetes, and neurological effects.

Q3: What is the EPA’s maximum contaminant level (MCL) for arsenic in drinking water?

The EPA has set a maximum contaminant level (MCL) of 10 parts per billion (ppb) for arsenic in drinking water to protect public health.

Q4: Can boiling water remove arsenic?

No, boiling water is not an effective method for removing arsenic, as it does not change the solubility or concentration of the contaminant. Filtration methods such as activated alumina, reverse osmosis, ion exchange, or adsorptive media are recommended for arsenic removal.

Q5: Are at-home test kits accurate for detecting arsenic in water?

At-home test kits can provide a general indication of arsenic levels in water, but they may not be as accurate as professional laboratory testing. For the most reliable results, consider sending a water sample to a certified laboratory for analysis.

Q6: How often should I replace filters in my arsenic filtration system?

The frequency of filter replacement depends on the type of filtration system, the concentration of arsenic in the water, and the overall water quality. Generally, filters should be replaced every 6 to 12 months, but always refer to the manufacturer’s guidelines for specific recommendations.