Naturally Occurring Water Contaminants in North Carolina

Not all drinking water contamination comes from industrial pollution or aging pipes. Some contaminants occur naturally underground as water moves through soil, sediment and rock, and can vary based on your geographic location.

In North Carolina, naturally occurring minerals, metals and radioactive elements can enter groundwater and private wells over time. While public water systems are regulated and tested, private well water is not — making water testing essential for home and business owners on private wells.

These contaminants are not unique to NC, however, regional geology can make them more common in certain areas. No matter where you live, the only way to know what’s in your water is through proper testing.

Which Naturally Occurring Contaminants Are Common in NC?

Many water issues found in North Carolina wells begin underground, where minerals, metals and radioactive elements can dissolve into groundwater naturally over time.

• Radioactive elements from natural mineral deposits, such as uranium and radium
• Metals and minerals dissolved from soil and rock, such as arsenic, iron and manganese
• Naturally occurring gases such as radon, released during groundwater movement

These can be found in both well water and municipal water, though private wells are often more vulnerable due to their source and a lack of treatment and regulation.

Even when contaminant levels fall within the current EPA drinking water standards, many homeowners choose to better safeguard their health through water treatment. Studies suggest that chronic exposure to certain radioactive elements and heavy metals, even at relatively low levels, may still raise health concerns over time.

1. Radon

Radon is a naturally occurring radioactive gas formed from the breakdown of uranium in soil and rock. It can dissolve into groundwater and enter private wells.

When water is used for showering, laundry or dishwashing, radon may be released into the air through aeration. Radon exposure risk is more commonly associated with indoor air, though drinking water may pose minor risks when radon exists at elevated levels.

According to the EPA, long-term radon exposure can increase lung cancer risk. Since radon cannot be seen, smelled or tasted, testing is essential. There is currently no maximum contaminant level (MCL) for radon in drinking water.

2. Arsenic

Arsenic commonly enters groundwater through erosion of surrounding rock and soil, and has no taste, smell or visible appearance.

Public water systems are required to monitor arsenic levels, with a maximum contaminant level (MCL) of 10 parts per billion.

Long-term arsenic exposure has been linked in studies to certain cancers and cardiovascular issues, depending on the concentration and duration.

3. Uranium & Radium

Uranium and radium are both radioactive elements that can make their way into groundwater, often found together. Due to erosion and as water moves through mineral-rich rock formations, trace amounts of uranium and radium can dissolve into the water supply.

Parts of Central and western North Carolina contain naturally occurring uranium-bearing rock formations, which may increase the likelihood of uranium and radium entering groundwater. Central and North Texas, parts of Georgia, the Ozarks, Michigan and Wisconsin also may have higher levels of uranium and radium in groundwater.

The current MCL set by the EPA and legally enforceable, is 5 pCi/L for radium (combined Ra-226 and Ra-228), and 30 µg/L for uranium in public drinking water systems.

Like radon and arsenic, these radioactive contaminants cannot be detected through taste, smell or appearance alone. Long-term exposure to elevated levels of radioactive contaminants in drinking water has been linked to increased cancer risk, while uranium exposure can impact kidney function over time.

4. Iron & Manganese

Manganese and iron are both common minerals found in North Carolina soil and rock, contributing to well water problems for many homeowners.

While typically not considered major health concerns at lower levels, these minerals can create frustrating issues throughout the home, from black or orange staining and metallic taste, to buildup inside plumbing and appliances.

Iron in water can exist in several different forms, including:

• Ferrous iron
• Ferric iron
• Colloidal iron
• Bacterial iron

The type of iron present impacts both how the water looks and the best treatment approach.

The EPA classifies iron and manganese as part of their Secondary Drinking Water Standards, which are not legally enforceable but exist to address water’s taste, odor, staining and aesthetic water quality concerns.

For iron, the secondary maximum contaminant level (SMCL) is 0.3 mg/L, with manganese at 0.05 mg/L. In general, iron in water is considered more of an aesthetic and plumbing issue, while elevated manganese exposure has been associated with potential neurological impacts at higher concentrations long-term.

How Homeowners Can Protect Their Water

Cleaner water starts with professional water testing. Since many naturally occurring contaminants cannot be seen, smelled or tasted, this is the only way to understand what’s in your water and the best solution.

Treatment options will depend on the specific contaminants present, but may include:

• Reverse Osmosis (RO): Purification significantly reduces contaminants such as arsenic, uranium and dissolved solids, as well as forever chemicals and other complex contaminants. Often used at the under-sink, point-of-use level.
• Whole-Home Filtration: Designed to reduce sediment and/or chemical contaminants while improving taste and odor, depending on the filter media. Whole-home filtration protects water used for drinking as well as cooking, bathing, laundry, dishes and other applications throughout your home.
• Water Softeners & Specialty Systems: Water softeners are designed to remove the majority of hardness minerals from water, preventing plumbing and fixture staining and buildup. Specialty systems from Kinetico can treat less common contaminants and water issues, such as radon.

At Kinetico, we’re here to help you enjoy cleaner, better-tasting water without compromise. Get started today with a free, no-obligation water test.