How to Identify Contaminants in Your Drinking Water

Written by Craig "The Water Guy" Phillips

To identify contaminants in your drinking water, we can't rely on sight, smell, or taste alone — dangerous substances like arsenic, PFAS, and lead are completely invisible. Start by knowing your source: public utility customers should review their Consumer Confidence Report, while well owners need proactive testing. Collect samples through a certified lab, testing for bacteria annually and chemicals every few years. Stick around, because what we uncover next could change how you think about every glass you pour.

Key Takeaways

• Request your utility's Consumer Confidence Report or assess nearby agriculture, industry, and landfills to identify likely contaminants in your water.
• At-home test strips provide quick screening, but certified labs can detect 200+ contaminants with far greater accuracy and reliability.
• Collect samples correctly: use sterile bottles, follow lab-specific instructions, and label with location, date, time, and recent plumbing changes.
• Many dangerous contaminants—including arsenic, PFAS, and lead—are completely odorless, tasteless, and invisible, making professional lab testing essential.
• Test for bacteria annually and check nitrates, lead, arsenic, and VOCs every three to five years or after flooding.

Public System or Private Well: Where Your Water Comes From

Before we can identify what might be lurking in our water, we've got to know where that water actually comes from. That single distinction — public system or private well — changes everything about how we monitor, test, and protect what we drink.

Before you can protect what you drink, you need to know exactly where it comes from.

Roughly 90% of Americans receive water from a public utility regulated under the Safe Drinking Water Act. That federal oversight matters — it means mandatory testing, reporting, and accountability.

The remaining 23 million-plus households rely on private wells, where none of that federal protection applies. Well owners are entirely responsible for their own water quality.

Knowing which category we fall into shapes every decision that follows. It determines what records we can access, what tests we need, and how proactively we must act.

Choose the Right Drinking Water Test for Your Situation

Once we ascertain whether we're on a public system or a private well, the next step is choosing the right test — and that choice matters more than most people realize. Start by reviewing your utility's Consumer Confidence Report or researching local land use — agriculture, industry, and landfills each signal specific threats like nitrates, pesticides, or industrial solvents.

For quick screening, at-home test strips work fine, but they're imprecise — always confirm positives through a certified lab. For thorough results, certified labs test 200+ contaminants, with individual analytes running $20–$100.

Test for bacteria annually, and tackle nitrates, lead, arsenic, and VOCs every three to five years — or immediately after flooding, plumbing work, or a nearby chemical spill. Targeted testing saves money and delivers answers that actually matter.

How to Collect & Submit a Water Sample Without Errors

Getting the sample right is where accuracy either lives or dies — and the good news is that a certified lab does most of the heavy lifting for us.

Start by contacting a state- or EPA-certified lab through your local health department. They'll supply the right bottles, written instructions, and sometimes a technician.

For bacterial tests, we want a first-draw cold-water sample after 6–12 hours of nonuse, collected in a sterile bottle without touching the cap's interior.

Chemical tests like lead or nitrates may require flushed samples — the lab tells us which.

Label everything: name, address, tap location, date, time, and any recent plumbing work.

Submit within the lab's required window, keep samples cool and dark, and call ahead if anything feels unclear.

Contaminants Most Likely Hiding in Your Tap or Well Water

Knowing what's actually in our water changes how urgently we act — and a few contaminants show up far more often than most people expect.

What we know about our water determines how fast we move — and most people are working with the wrong picture.

Here's what we're most likely dealing with:

• Coliform bacteria and nitrates — common in private wells, especially after flooding, and capable of causing acute illness fast
• Lead — silently leaching from corroding pipes, contributing up to 60% of an infant's total exposure
• Arsenic and radon — naturally occurring, geology-dependent, and completely undetectable without testing
• PFAS and industrial chemicals — odorless, tasteless, and requiring laboratory analysis plus reverse osmosis treatment to address effectively

None of these announce themselves. They don't smell, taste, or look different.

That invisibility is exactly why testing isn't optional — it's the only way we actually know.

Act on Your Water Test Results Before the Problem Spreads

A positive test result is where most people freeze — and that hesitation is exactly what lets the problem grow. We've seen small contamination issues become household crises simply because no one acted fast. Here's your action map:

Contaminant	Immediate Action
Coliform/E. coli	Switch to bottled or boiled water immediately
Lead above 15 ppb	Stop drinking tap; use certified lead-removing filter
Nitrates above 10 mg/L	Protect infants and pregnant household members first
Arsenic above 10 ppb	Install point-of-use certified treatment system
PFAS/VOCs	Follow health-department guidance; consider reverse osmosis

Beyond those steps, we must preserve a sample for confirmatory testing, notify everyone in the household, schedule follow-up tests post-remediation, and report findings to our local health department. Speed protects people.

Frequently Asked Questions

How Do I Tell if My Drinking Water Is Contaminated?

We can't rely on smell, taste, or appearance alone—many contaminants are invisible. Test annually at a certified lab, review your Consumer Confidence Report, and watch for cloudy water, odd odors, or unexplained illness.

What Is the Safest Brand of Bottled Water to Drink?

We recommend brands like Evian or FIJI—they publish full lab reports confirming contaminants stay below EPA limits. Look for NSF/ANSI 53 or 58 certification and verified third-party testing targeting your specific contaminant concern, whether PFAS, arsenic, or microbes.

Can Contaminated Water Make You Dizzy?

Yes, contaminated water can make you dizzy. We're talking microbial infections triggering dehydration, or chemical culprits like lead and nitrates disrupting your nervous system. If dizziness follows tap water consumption, we'd recommend switching to bottled water immediately.

Can Tap Water Cause IBS?

Tap water doesn't directly cause IBS, but contaminated water can trigger IBS-like flares. Pathogens and chemical contaminants irritate your gut, disrupt your microbiome, and mimic IBS symptoms—making it hard to distinguish between the two.