I've been working with well water systems for a long time now, and the importance of well water testing never changes. Clean water matters so much more than most people realize. It directly impacts the health of your family and the peace of mind you get every time you pour a glass. Even the little “everyday” things most folks take for granted, like rinsing vegetables or letting your grandkids splash around in the sink, demand pristine water.
Frequent well water testing is how to stay ahead of invisible problems that could lead to serious health issues. From bacterial contamination to long-term exposure to metals, some of the most common issues you can find are also the ones people least expect. Here’s what to look out for:
- Coliform bacteria and E. coli
- Nitrates and nitrites
- Arsenic
- Lead
- Iron and manganese
- Sulfur (hydrogen sulfide)
- Pesticides and herbicides
- Volatile organic compounds (VOCs)
Contaminants are sneaky, but knowledge is power. You deserve to know what you might be up against, and what you can do to protect the people you care about, so keep reading.
Coliform Bacteria and E. coli
Bacteria are the biggest red flag to look for when running well water tests. Coliforms, especially E. coli, don’t belong in your water under any circumstances. And unfortunately, they show up more often than people think.
Most of the time, it’s a result of surface water runoff getting into the well. Heavy rains, failing septic systems, animal waste, or a cracked well cap can all open the door. Once they're in, they don't just go away. If you’ve ever had a stomach bug and didn’t know why, you’d be surprised how often the water source is to blame.
What do I recommend when bacteria pop up? Shock chlorination is a good short-term fix, but it’s not enough by itself. I’ve learned that regular testing is valuable, especially after storms or seasonal flooding. And for long-term protection, it’s a great idea to install a UV disinfection system. It’s safe and effective.
Nitrates and Nitrites
I have clients who live near farmland, and I know just how quickly fertilizers can seep into the groundwater. Nitrates and nitrites often come from lawn treatments, septic tanks, or animal waste runoff. If your well is downhill from any of that, testing is absolutely essential.
What makes these contaminants so dangerous is how fast they impact vulnerable people, especially infants. High nitrate levels in drinking water can cause “blue baby syndrome,” a condition where oxygen can’t circulate properly in a newborn’s body. It’s serious. It’s also entirely preventable.
From my experience, reverse osmosis systems and distillation units are the most effective ways to remove these compounds. It’s also important to keep runoff from pooling near the well in the first place. A bit of landscaping or redirection can take care of that.
Arsenic
People are always shocked when they hear “arsenic,” but the truth is, it’s naturally occurring in many parts of the country. It’s in the soil, and over time, it makes its way into groundwater.
Unlike bacteria, arsenic won’t make you sick overnight. But over time, it’s been linked to cancer, skin damage, and internal organ issues. That’s not a risk I’m willing to take with my own family.
The good news is, it’s manageable. Many homeowners install point-of-use reverse osmosis systems under their sinks, and they work exceptionally well. For those with higher levels, whole-house filtration might be necessary. Either way, monitoring and well water testing is non-negotiable. This isn’t a once-and-done type of problem.
Lead
Old homes have charm, but they also have old plumbing. I’ve lost count of how many tests I’ve run that come back with lead contamination. It usually comes from deteriorating pipes or solder, especially in systems installed before 1986.
The scariest part? You can’t see it. You can’t taste it. And yet, lead is devastating, especially for kids. It’s been linked to developmental delays, learning issues, and long-term neurological damage.
If there’s even a hint of lead in your plumbing, the advice stays the same: replace those pipes if you can. In the meantime, install a filter certified to remove lead, and make sure you’re using it consistently. It’s one of the most important steps you can take for your family’s health.
Iron and Manganese
These two compounds go hand in hand. Plenty of tests that show both iron and manganese at elevated levels, and while they’re not usually dangerous to your health, they’re a serious nuisance.
We’re talking about rust-colored stains on laundry, metallic-tasting water, clogged pipes, and even broken appliances. I’ve had clients ask if their washer was broken, only to find out it was the iron in their water causing buildup.
A water softener is always recommended, or for higher concentrations, oxidation and filtration systems. The fix is straightforward, and the results are immediate. Your laundry and your faucets will thank you.
Sulfur (Hydrogen Sulfide)
Have you noticed that awful rotten egg smell? You’ll never forget it once you’ve smelled it. Hydrogen sulfide is a naturally occurring gas that can show up in groundwater. In some cases, it’s caused by bacteria in the well. It’s not usually a health risk, but it corrodes pipes, wears down plumbing fixtures, and makes your water incredibly unpleasant. Guests notice. So does your dishwasher.
For most households, aeration systems or oxidizing filters can clear it up fast. It’s also best to invest in activated carbon filters for people who want an added layer of odor removal. It’s a fixable problem, but only if you test for it.
Pesticides and Herbicides
Agricultural chemicals seep into groundwater more easily than people realize, especially when it rains. These contaminants are incredibly dangerous. Pesticides and herbicides have been linked to liver and kidney damage, hormone disruption, and even cancer. Once they’re in your well, they’re not going anywhere without help.
Here’s what works best: testing frequently and using an activated carbon filtration system. Also, avoid applying any chemical treatments anywhere near the wellhead. Prevention is just as important as treatment.
Volatile Organic Compounds (VOCs)
Out of all the things I test for, VOCs are the most misunderstood. They’re not just a problem near gas stations or industrial sites. They can be found in suburban and rural wells, usually from solvents, fuels, or old household products that were improperly stored or discarded.
These compounds are extremely dangerous, and they build up over time. Long-term exposure has been linked to cancer, liver failure, and kidney disease. And because VOCs evaporate, they can contaminate both your water and the air in your home.
The best way to handle VOCs is granular activated carbon filtration. It’s proven. And just as importantly, I always recommend tightening up storage habits around the home. Don’t store gas, oil, or cleaners anywhere near your well. Better yet, store them in sealed secondary containers. VOCs are one of those issues where you won’t know you have a problem until it’s serious, and that’s exactly why regular testing is so important.
Conclusion
If you have a well, testing is your responsibility. Whether it’s bacteria, nitrates, lead, or VOCs, each contaminant tells a story about your environment and your habits. They affect your long-term health, and every one of them is manageable if you catch it early. I’ve seen firsthand how the right well water testing and treatment plan can transform a household’s water quality. When your family’s and your visitors’ health is on the line, that peace of mind is priceless.
