Epidemiology: Occupational and Environmental

Private Wells: Frequently Asked Questions about Testing

When should a well be tested?

New Wells

All newly constructed private wells in North Carolina must be tested by the North Carolina State Laboratory of Public Health (note: contact your local health department to schedule a test through the State Lab) or a state-certified commercial laboratory prior to establishing the well as a source of drinking water. Tests for bacterial and chemical contaminants should be conducted within 30 days of the well completion.

Existing Wells

See the testing recommendations below. Well owners for existing wells can also contact their local health department or a state-certified commercial laboratory to request well water testing.

• Well owners should check the wellhead once a year to make sure it is working properly and ensure that there are no cracks or openings where contaminants can get into your groundwater.
• Well water should be tested after repairs or replacements to any of the well components and after flooding events, since contaminants may enter your well when it is opened or if the wellhead is underwater.

How/where do you get your water tested?

Generally, private well water can be tested via the North Carolina State Laboratory (through your local health deparment) or a state-certified commerical lab. However, specific procedures, fees and ordinances may vary from county to county. Contact the Environmental Health program at your local health department for information about the specific procedures to have your water tested.

• Find your local health department
• Search for state-certified commercial laboratories for drinking water testing

How often should I test my well water?

• Every Year: Test for total and fecal coliform bacteria.
  • Also check the wellhead once a year to make sure it is working properly and ensure that there are no cracks or openings where contaminants can get into your groundwater.
• Every Two Years: Test for heavy metals, nitrates, nitrites, lead and copper.
• Every Five Years: Test for pesticides and volatile organic compounds (VOCs). If you know of a particular pesticide that is applied in your area, test yearly.

Special situations that may require additional testing:

• If you are pregnant or have an infant at home, you should test your water for nitrates. If you have nitrates in your well water, do not drink the water or use it to prepare baby formula. Use an alternative source of water instead. Boiling water does not remove nitrates.
• If there are known problems with well water in your area,
• If you have experienced problems near your well (i.e., flooding, land disturbances, and nearby waste disposal sites),
• If you replace or repair any part of your well system,
• If you notice a change in water quality (i.e., taste, color, odor).

What activities near my home can contaminate my well?

• flooding;
• surface run-off that carries pollutants through the soil and into underground water supplies (such as rainwater that washes off of parking lots and roadways);
• agricultural activities;
• erosion of mineral deposits;
• decomposing waste;
• construction activities;
• toxic spills;
• leaking storage tanks and landfills;
• industrial discharges into surface waterways;
• underground injection of waste products.

What tests should you do?

Certain minerals or chemicals may be present in your water, depending on the geology and land use in your area. Many wells in North Carolina have too much lead, arsenic, iron, manganese, low pH, and harmful bacteria.

Last Modified: November 18, 2021