What Contaminants Are in Drinking Water? Top 10 Risks & the Best Ways to Remove Them
- 19 hours ago
- 3 min read
What Contaminants Are in Drinking Water?
Common drinking water contaminants include lead, chlorine, PFAS, arsenic, nitrates, bacteria, heavy metals, pesticides, pharmaceuticals, and microplastics.
Some affect taste and odor. Others may create health risks depending on concentration, long-term exposure, age, and overall water quality.
Water can appear clean while still containing dissolved contaminants, which is why testing and proper filtration matter.
Quick Answer: What Are the Most Common Water Contaminants?
The most common contaminants found in tap water or well water are:
Chlorine / Chloramine
Lead
PFAS
Arsenic
Nitrates
Bacteria / Viruses
Heavy Metals
Pesticides
Pharmaceuticals
Microplastics
Top 10 Drinking Water Contaminants Explained
1. Chlorine & Chloramine
Used to disinfect municipal water systems.
Common Issues:
Chemical taste
Odor
Dry skin
Irritation for sensitive users
Best Filter:
2. Lead
Usually enters water through aging pipes, solder, and plumbing fixtures.
Why It Matters:
Lead exposure may be especially concerning for children and pregnant women.
Best Filter:
Reverse osmosis
NSF-certified lead filters
3. PFAS “Forever Chemicals”
PFAS are synthetic chemicals linked to industrial products, coatings, and firefighting foam.
Why They Matter:
PFAS persist in the environment and may accumulate over time.
Best Filter:
Reverse osmosis
4. Arsenic
Arsenic may occur naturally in groundwater and private wells in some regions.
Best Filter:
Reverse osmosis
5. Nitrates
Often linked to fertilizer runoff and agricultural groundwater contamination.
Higher Concern For:
Infants and private well users.
Best Filter:
Reverse osmosis
Ion exchange
6. Bacteria & Viruses
Can occur from well contamination, flooding, sewage intrusion, or treatment failures.
Best Filter:
UV disinfection
Certified microbiological filtration
7. Heavy Metals
Examples include chromium, mercury, cadmium, copper.
Sources:
Industrial discharge, corrosion, natural geology.
Best Filter:
Reverse osmosis
8. Pesticides & Herbicides
Can enter water from agricultural runoff.
Best Filter:
Reverse osmosis
9. Pharmaceuticals
Trace residues from medications and household chemicals may enter wastewater streams.
Best Filter:
Carbon filtration
Reverse osmosis
10. Microplastics
Small plastic particles found in many water sources, including bottled water.
Best Filter:
Reverse osmosis
Ultrafiltration
Is Tap Water Safe?
Often yes, but safety depends on:
Local treatment quality
Pipe infrastructure
Source water conditions
Home plumbing age
Private well maintenance
Specific contaminants present
Municipal water may meet legal standards while still containing taste, odor, or trace contaminants many households choose to filter.
Is Bottled Water Safer Than Tap Water?
Not automatically. Bottled water quality varies and may still contain microplastics. Many brands source from municipal supplies and then add additional treatment.
Filtered tap water is often more cost-effective and environmentally sustainable.
How to Know What Is in Your Water
Recommended Steps
Read your annual water quality report
Test private wells yearly
Test older homes for lead risk
Match filtration to actual contaminants
Retest after installation
Frequently Asked Questions
What is the most dangerous contaminant in drinking water?
It depends on concentration and exposure. Common concerns include lead, PFAS, arsenic, nitrates, and bacteria.
Does boiling water remove lead or PFAS?
No. Boiling kills microbes but usually does not remove metals or chemical contaminants.
What is the best filter for tap water?
It depends on the contaminant. Carbon is excellent for chlorine; RO is stronger for dissolved contaminants.
Are private wells safer than city water?
Not automatically. Wells require regular testing and treatment.
Expert Summary
If you do not know what is in your water, start with testing.
If contaminants are present:
RO = dissolved contaminants
UV = microbes
The best water filter is the one designed for your specific water profile.
Everfilt® designs industrial, agricultural, municipal, and commercial water treatment systems for many contaminants, like iron, arsenic, manganese, PFAS, chlorine, nitrates, and much more. Request a Quote for a Customized Filtration Solution.