What is Arsenic?
Arsenic is a naturally occurring element that can be found in both organic and inorganic compounds. Organic arsenic compounds are harmless, but they can become dangerous for human consumption when paired with inorganic substances.
So, if there’s arsenic in your well water, it’s vital that you remove it.
In this guide, we cover the most effective ways to remove arsenic from well water. We also discuss the costs of doing so, how to test for arsenic in well water, the health effects of drinking water contaminated with arsenic, and more.
The Most Effective Ways to Remove Arsenic From Well Water
The 4 most effective ways to remove arsenic from well water are:
- Reverse osmosis
- Distillation
- Adsorptive media
- Anion exchange
Here’s how they work.
1. Reverse Osmosis
Reverse osmosis (RO) removes arsenic by pushing the water through a semi-permeable 0.0001-micron membrane, which prevents arsenic molecules from passing through. The molecules remain trapped on the membrane while the purified water passes through.
Periodically, the membrane is flushed and regenerated through a process called regeneration so that it can continue to filter out arsenic molecules effectively.
Depending on the make and model, an RO system can remove up to 95% of arsenic molecules from water. Refer to our article on best arsenic water filters for product recommendations.
2. Distillation
When water is distilled, it’s boiled until it turns into gas. In its gas state, the water can no longer hold impurities such as arsenic. Then, the gas is passed through coils to cool it until it returns to its liquid state. Finally, the purified water is collected in a container to be used as drinking water or for other purposes.
Distillation is a highly effective way to remove arsenic from water. However, the process is time-consuming and a distillation cycle doesn’t typically produce a large volume of purified water. So, it’s not the best option if you need enough clean water to supply an entire household.
3. Adsorptive Media
Adsorptive media filters that feature activated alumina or iron-based sorbents are also an effective way to remove arsenic from your water. In addition to arsenic, they also remove other dangerous heavy metals and chemicals such as uranium.
Adsorptive media are most commonly used in industrial-level water processing since they’re ideal for treating large water beds. Yet, despite the big strides made in water filtration technology in recent years, finding an adsorptive media filter suitable for household use can be difficult.
4. Anion Exchange
The anion exchange process is similar to the ion exchange process water softeners employ. It utilizes an ion resin bed to remove ionic contaminants. Unlike ion exchange, which removes minerals like calcium and magnesium (cations), anion exchange can also remove negatively charged ions like arsenic and nitrate (anions).
The ion resin catches and encloses arsenic particles in the water, which are then replaced with sodium ions.
Anion exchange devices are only effective for low TDS water and can’t be used if the arsenic level exceeds 100 ppb.
Cost of Removing Arsenic From Water
Depending on the arsenic removal method, it costs between $100-$3,000 to remove arsenic from water. Here’s a breakdown of the average costs of using the most common methods:
- Distillation: $100-$150
- Reverse osmosis: $250-$1,000
- Point-of-use filter with adsorptive media: $150-$400
- Point-of-entry filter with adsorptive media: $1,500-$3,000
- Anion exchange resin: $300-$500 per one cubic foot
How to Test for Arsenic in Well Water
If you own a private well, you should have your water tested at least twice a year. However, if you suspect that there’s arsenic in your water, you can deviate from your biannual water-testing schedule and test immediately.
Since arsenic is an odorless and tasteless contaminant, it’s impossible to detect its presence through the senses. This means you need to either send a sample to a lab or use water testing kits.
1. Water Testing Kits
A home water testing kit specifically designed to test for arsenic is the easiest way to determine the arsenic levels in your water.
Just fill a glass with water and place a section of the testing strip inside. Leave it inside the water in line with the specifications of the manufacturer. After 10 minutes, the color chart included with the kit will indicate the amount of arsenic in your water.
2. Private Labs
A more reliable way to test well water is to contact your local health department or send a water sample to a certified lab. They will be able to effectively test and determine the arsenic levels in your water. Lab testing is far more accurate than at-home testing. However, it’s also more expensive.
Is Arsenic More Likely to Be Found in Well Water?
A study by Columbia University health researchers shows that arsenic contamination can occur in both well water and municipal water but is more likely in well water. But why is this the case?
Well, if the soil, bedrock, and groundwater in a region naturally contain arsenic, the water in the wells in that area can be contaminated. This is particularly true for wells that are drilled into bedrock in arsenic-rich areas.
Health Effects of Drinking Arsenic Contaminated Water
For drinking water to be safe, the EPA states that it shouldn’t contain more than 10 ppb of arsenic. Exposure to water containing more than this level of arsenic can lead to dire, chronic health problems.
This includes short-term and long-term health issues such as:
Short-term problems:
- Neurological problems (numbness and burning in some regions of the body)
- Nausea and vomiting
- Fatigue
- Cardiovascular problems
- Decreased white and red blood cell production
Long-term problems:
- Thickening of the skin
- Skin discoloration
- Persistent sore throat
- Growths on feet and hands
- Digestive problems
- Prostate and kidney cancer
- Skin darkening
It’s important to note that long-term exposure typically affects the skin first. This includes issues like pigmentation changes, skin lesions, and an increased risk of skin cancer. Also, symptoms can lie dormant before you start experiencing their effects.
