Testing City Water: If your home receives drinking water from a city or municipal water system, you might assume that there is no reason to test the water yourself. After all, public water utilities are required to monitor drinking water and meet federal and state standards.
That’s an important protection—but it doesn’t necessarily tell you everything about the water coming out of your kitchen faucet.
Public water systems regularly test water at locations throughout their distribution systems, and community water systems must provide customers with an annual Consumer Confidence Report (CCR) describing their water quality. (US EPA)
However, water can change after it leaves the treatment plant. Household plumbing, service lines, faucets, fixtures, and water sitting in pipes can affect the water that ultimately reaches your glass. Lead is one particularly important example because it can enter water through plumbing materials even when the municipal water supply itself meets regulatory requirements. (CDC)
That is why testing city water at the tap can provide information that your city’s annual water report cannot.
This guide explains when to test municipal water, what to test for, how to collect a sample, where to get it tested, and how your results can help you choose an appropriate water filtration system.
Table of Contents: Testing City Water
- What Is City Water?
- Does City Water Need to Be Tested?
- City Water Reports vs. Home Water Testing
- When Should You Test City Water?
- What Should You Test City Water For?
- Testing City Water for Lead
- Testing for Copper
- Testing for Chlorine and Chloramines
- Testing for PFAS
- Testing for Arsenic and Other Contaminants
- Should You Test for Bacteria?
- How to Collect a City Water Sample
- Where to Get City Water Tested
- How Much Does City Water Testing Cost?
- How to Read City Water Test Results
- What If Your City Water Test Shows a Problem?
- Does City Water Need a Filter?
- Is Reverse Osmosis Good for City Water?
- City Water Testing Checklist
- Frequently Asked Questions
- Final Thoughts
What Is City Water?
“City water” generally refers to drinking water supplied by a public water system.
Depending on where you live, your water may be supplied by:
- A city water department
- A municipal water utility
- A county water district
- A regional water agency
- A public water company
- Another community water system
The water may originate from surface-water sources such as reservoirs and rivers or from groundwater sources.
Public water systems treat and monitor drinking water to meet applicable drinking-water standards. The EPA establishes federal drinking-water standards, while states may have additional requirements. (CDC)
For most households receiving municipal water, the first step in understanding water quality is to find the latest water-quality report.
Does City Water Need to Be Tested?
It depends on what you want to know.
Municipal water systems already conduct required monitoring, so homeowners generally don’t need to perform routine testing simply because their water comes from a public utility.
However, there are situations where testing your own tap water can be valuable.
For example, you may want to test if:
- Your home has older plumbing
- You are concerned about lead
- You have an older service line
- Your water has changed in taste or odor
- Your water has changed color
- You recently moved into an older home
- You are installing a filtration system
- You have a specific contaminant concern
- Your water utility has issued an advisory
- You want to verify the performance of a water filter
- You want to establish a baseline for your home’s water
The CDC recommends reviewing your public water system’s annual water-quality report and contacting the water utility or health department if you have concerns. (CDC)
City Water Reports vs. Home Water Testing
One of the most important distinctions is between utility testing and household tap testing.
Your City’s Water Quality Report
A Consumer Confidence Report provides information about the public water system.
It can tell you:
- Where your water comes from
- Which regulated contaminants were detected
- Reported contaminant levels
- Applicable regulatory standards
- Potential health effects
- Whether violations occurred
Community water systems must provide these reports annually. (CDC)
Your Home’s Water Test
A laboratory test of your home’s tap water tells you what was detected in that particular sample from your property.
This distinction is especially important for contaminants associated with plumbing.
For example, a city may provide water that complies with applicable standards at the treatment plant and throughout its distribution system, while lead could still enter water through a home’s plumbing.
The CDC identifies lead pipes, faucets, fixtures, solder, and other plumbing components as potential sources of lead in tap water. (CDC)
The two approaches work together.
Water report: What is happening across the public water system?
Home testing: What is happening at my faucet?
For a complete overview of water-testing methods, see Revosmo’s How to Test Your Drinking Water.
When Should You Test City Water?
There isn’t a universal requirement for every homeowner to test municipal water on a particular schedule.
Instead, consider testing when you have a specific reason to investigate your water.
When You Move Into an Older Home
Older homes can contain plumbing materials that differ significantly from newer construction.
If you’re unsure what materials were used in your home’s plumbing or service line, testing can provide useful information.
When You Are Concerned About Lead
Lead deserves special attention because contamination can originate from plumbing between the municipal supply and your faucet.
The CDC recommends contacting your local water authority about potential lead service lines and asking about water testing. Many public water systems will test drinking water for residents upon request. (CDC)
When Your Water Changes
A noticeable change in:
- Taste
- Odor
- Color
- Cloudiness
is a good reason to investigate.
A change doesn’t necessarily mean your water is unsafe, but it shouldn’t automatically be dismissed either.
After Plumbing Work
Consider testing after significant plumbing work, particularly if pipes, fixtures, service lines, or other components have been replaced.
When Installing a Water Filter
Testing before installing a filtration system can help you understand what you’re actually trying to remove.
The CDC recommends testing water and choosing a treatment system designed to address the specific chemicals or germs of concern. (CDC)
What Should You Test City Water For?
The best testing panel depends on your concerns, your location, your home’s plumbing, and information from your local water utility.
Potential tests include:
- Lead
- Copper
- Chlorine
- Chloramines
- Arsenic
- Nitrate
- Fluoride
- PFAS
- Iron
- Manganese
- Mercury
- Chromium
- VOCs
- Bacteria
- pH
- TDS
- Hardness
You don’t necessarily need to test for every substance on this list.
A better approach is to identify the most relevant potential contaminants and then choose appropriate laboratory testing.
Your city’s annual water report is a useful starting point because it provides information about contaminants detected in the public water system. (US EPA)
Testing City Water for Lead
Lead is one of the most important reasons a homeowner may want to test municipal water.
Lead can enter drinking water through:
- Lead service lines
- Lead pipes
- Faucets
- Brass fixtures
- Plumbing solder
- Pipe fittings
- Other plumbing components
The CDC notes that corrosion of plumbing materials can cause lead to enter drinking water. (CDC)
Your city’s water report may not tell you exactly what is in your faucet.
If you are concerned about lead, contact your water utility and ask:
- Does my property have a lead service line?
- What type of service line connects my home to the water main?
- Does the utility provide residential lead testing?
- Are there known lead issues in my neighborhood?
- What sampling procedure should I use?
You can also have your water tested by a certified laboratory.
The CDC recommends testing when lead exposure is a concern and notes that many public water systems offer testing to residents. (CDC)
Testing for Copper
Copper is another metal that can enter drinking water through plumbing.
Copper pipes are common in residential construction, and water chemistry can influence corrosion.
A copper test may be appropriate if:
- You have older plumbing
- You notice blue-green staining
- You have a metallic taste
- You are experiencing plumbing corrosion
- You have a known water-chemistry problem
Testing for copper alongside lead can provide a more complete picture of potential plumbing-related metal contamination.
Testing for Chlorine and Chloramines
Municipal water systems commonly use disinfectants to control microorganisms.
Two disinfectants you may encounter are:
- Chlorine
- Chloramine
These disinfectants help protect water as it travels through the distribution system.
Some homeowners test chlorine or chloramine because of:
- Taste
- Odor
- Shower-water concerns
- Skin sensitivity
- Aquarium use
- Filtration-system design
If your goal is improving taste and odor rather than addressing a health-based contaminant, a carbon filter may be sufficient.
However, always check the specifications of a particular filter before assuming that it will reduce a specific contaminant.
Testing for PFAS
PFAS, sometimes called “forever chemicals,” are a large family of manufactured chemicals.
PFAS have become an increasingly important drinking-water concern.
Your local water report may contain PFAS information, but homeowners with specific concerns may want additional testing.
Potential reasons include:
- Your utility has reported PFAS
- PFAS have been detected in your region
- You live near a potential PFAS source
- You want independent confirmation
- Your local environmental or health agency recommends testing
The CDC lists PFAS among chemicals that can contaminate tap water. (CDC)
If you test for PFAS, use a laboratory and sampling procedure appropriate for PFAS analysis.
Testing for Arsenic and Other Contaminants
Municipal water systems monitor regulated contaminants according to federal and state requirements.
Depending on the source water and local conditions, your water report may include information about contaminants such as:
- Arsenic
- Nitrate
- Chromium
- Mercury
- Fluoride
- Radium
- Other regulated substances
The annual water report should be your first resource for understanding what has been detected in your public water system. (US EPA)
If you have a particular concern that isn’t adequately addressed by the report, consider additional testing.
Should You Test for Bacteria?
For most homeowners receiving properly treated municipal water, routine household bacteria testing isn’t necessarily required.
Public water systems are required to monitor for microbial contaminants and maintain treatment processes designed to protect public health.
However, additional testing may be appropriate in unusual circumstances.
Consider contacting your water utility or health department if:
- There has been a water-main break
- Your property experienced a plumbing failure
- You received a boil-water advisory
- Water entered your plumbing after an emergency
- Your water has an unusual appearance
- You have a specific microbiological concern
Tap water is not sterile, and disruptions to water systems can create opportunities for germs to enter pipes. (CDC)
Follow any instructions provided by your local water authority during a drinking-water advisory.
How to Collect a City Water Sample
Correct sampling is essential if you want meaningful laboratory results.
Different contaminants may require different sampling procedures, so always follow the laboratory’s instructions.
Step 1: Select the Correct Faucet
For drinking-water testing, the kitchen faucet is often a logical sampling location.
However, your laboratory may specify a particular faucet or sampling procedure.
Step 2: Use the Laboratory’s Container
Never assume an ordinary glass or plastic bottle is appropriate.
Use the sample container provided or approved by the laboratory.
Step 3: Follow the Sampling Instructions
Your instructions may specify:
- Whether to flush the water
- How long to run the faucet
- Whether to collect a first-draw sample
- Whether to remove the faucet aerator
- Whether the faucet needs to be disinfected
These details matter.
First-draw testing can be particularly important for lead.
Water that has been sitting in household plumbing can have a different contaminant concentration from water that has recently flowed through the pipes.
Step 4: Don’t Touch the Sample
Avoid touching the inside of the container or cap.
Step 5: Deliver the Sample Promptly
Some laboratory tests have specific holding-time requirements.
Follow the laboratory’s shipping or drop-off instructions carefully.
Where to Get City Water Tested
If you want independent testing, look for a state-certified drinking-water laboratory.
The EPA provides information about state certification programs and certified drinking-water laboratories. (US EPA)
You can also contact:
- Your city water department
- Your water district
- Your county health department
- Your state environmental agency
- A state-certified laboratory
Your water utility may provide residential testing, particularly for lead.
Before ordering a test, ask the laboratory:
“What contaminants should I test for based on my water source and location?”
You may get a much more useful answer than simply purchasing the largest available test panel.
How Much Does City Water Testing Cost?
Testing costs vary significantly depending on the contaminants being analyzed.
A basic test for a small number of parameters may be relatively inexpensive.
More specialized testing can cost substantially more, particularly for:
- PFAS
- VOCs
- Pesticides
- Radionuclides
- Specialized microbiological analysis
- Multiple heavy metals
The best way to control costs is to test strategically.
Start with your city’s water report and your specific concerns.
Then choose laboratory testing that fills the information gaps.
How to Read City Water Test Results
Once your laboratory results arrive, don’t look at the numbers in isolation.
Check:
1. Contaminant
What substance was detected?
2. Concentration
How much was detected?
3. Unit
Is the result expressed in:
- ppm
- ppb
- mg/L
- µg/L
- pCi/L
- Another unit?
4. Detection Limit
Could the laboratory detect extremely small concentrations?
5. Applicable Standard
Is there an EPA or state drinking-water standard relevant to the contaminant?
6. Sample Type
Was it a first-draw sample, flushed sample, or another sampling type?
7. Sample Date
When was the sample collected?
These details can make a major difference when interpreting results.
For a complete guide to water testing methods and interpreting results, visit Revosmo’s How to Test Your Drinking Water.
What If Your City Water Test Shows a Problem?
Don’t immediately buy a filtration system based on one unexpected number.
Instead:
1. Verify the Result
Contact the laboratory and ask whether a repeat sample is recommended.
2. Contact Your Water Utility
Ask whether the utility has detected the same contaminant.
3. Determine the Source
The contaminant may originate from:
- Municipal source water
- Distribution infrastructure
- Your service line
- Household plumbing
- A faucet or fixture
4. Determine the Appropriate Treatment
Different contaminants require different treatment technologies.
5. Retest After Treatment
If you install a filtration system, testing can help verify whether the system is actually reducing the contaminant.
Does City Water Need a Filter?
Not necessarily.
Public water systems are regulated and treated to meet drinking-water standards, and many households may not need additional filtration.
However, homeowners sometimes choose filtration for specific reasons, such as:
- Improving taste
- Reducing chlorine
- Reducing certain contaminants
- Addressing plumbing-related contamination
- Reducing dissolved solids
- Creating an additional treatment barrier
The CDC recommends testing your water and choosing a treatment system based on the contaminants or germs you actually want to remove. (CDC)
Don’t buy a filter simply because a water filter is advertised as “better.”
First identify the problem.
Then choose technology designed to address it.
Is Reverse Osmosis Good for City Water?
Reverse osmosis can be an effective point-of-use treatment option for many dissolved contaminants, but whether you need RO depends on your water and your goals.
RO systems typically use several stages, which may include:
- Sediment filtration
- Carbon filtration
- Reverse osmosis membrane
- Post-filtration
An RO system can be particularly attractive when a homeowner wants substantial reduction of dissolved substances rather than simply improving taste and odor.
However, not every contaminant is best handled by RO, and system performance varies.
Before purchasing a system, consider:
- Your water test results
- Incoming TDS
- Water pressure
- Water temperature
- Desired filtration performance
- Wastewater ratio
- Filter replacement costs
- Storage capacity
- Installation requirements
For a detailed explanation of RO technology and what to look for when choosing a system, read Revosmo’s The Ultimate Guide to Reverse Osmosis Systems.
City Water Testing Checklist
Use this checklist when evaluating your municipal drinking water.
Start With Your Water Utility
☐ Find your latest Consumer Confidence Report
☐ Identify your water source
☐ Review detected contaminants
☐ Check for violations
☐ Check for lead and copper information
☐ Look for PFAS information
☐ Contact the utility with questions
Consider Home Testing If
☐ You live in an older home
☐ You are concerned about lead
☐ You have older plumbing
☐ Your water’s taste has changed
☐ Your water’s odor has changed
☐ Your water’s appearance has changed
☐ You recently completed plumbing work
☐ You are considering a filtration system
☐ You have a specific contaminant concern
Potential Tests
☐ Lead
☐ Copper
☐ Chlorine
☐ Chloramine
☐ PFAS
☐ Arsenic
☐ Nitrate
☐ Fluoride
☐ Iron
☐ Manganese
☐ VOCs
☐ pH
☐ TDS
☐ Hardness
☐ Bacteria when appropriate
Frequently Asked Questions About Testing City Water
Do I need to test my city water every year?
Not necessarily. Public water systems are already required to monitor their water. For homeowners, additional testing is generally most useful when there is a specific concern, such as older plumbing, potential lead exposure, a noticeable change in water quality, or a need to verify filtration performance.
Is city water safe to drink?
Public water systems in the United States are regulated and required to meet applicable drinking-water standards. Your utility should notify customers if water quality does not meet applicable standards. (CDC)
However, water quality can also be affected by household plumbing.
Should I test my tap water for lead?
If you are concerned about lead, testing your tap water can be worthwhile, particularly if your home has older plumbing or a potentially lead-containing service line. The CDC recommends contacting your water authority about potential lead sources and water testing. (CDC)
Does my city’s water report tell me what is in my faucet?
Not necessarily.
The Consumer Confidence Report describes water-quality information for the public water system. It may not reflect conditions created by your home’s plumbing.
Where can I get my tap water tested?
You can contact your water utility, health department, or a state-certified drinking-water laboratory. The EPA maintains information about state laboratory certification programs. (US EPA)
Should I use a home water test kit?
Home test kits can be useful for preliminary screening of certain water characteristics, but laboratory testing is preferable when you need reliable information about a specific contaminant or need results for an important water-quality decision.
Is a TDS meter enough to test city water?
No.
A TDS meter measures an estimate of total dissolved solids. It does not identify individual contaminants such as lead, PFAS, bacteria, or arsenic.
Should I get an RO system for city water?
Not automatically. The best approach is to determine what you want to improve or remove first, then choose a treatment system designed for that purpose.
Final Thoughts
Testing city water can provide information that your municipal water report cannot.
Your local water utility’s annual Consumer Confidence Report is an excellent place to start. It tells you about the source of your water, regulated contaminants detected by the system, applicable standards, and compliance information. (CDC)
But your home’s water has another variable: the plumbing between the water system and your faucet.
This is particularly important for lead. Plumbing materials such as service lines, faucets, fixtures, solder, and pipes can affect the quality of water at the tap. (CDC)
If you’re concerned about your water, start by reviewing your city’s water report. Then determine whether additional testing makes sense based on your home’s age, plumbing, location, and specific concerns.
For a complete overview of drinking-water testing—including home test kits, laboratory testing, sampling, and interpreting results—visit Revosmo’s How to Test Your Drinking Water.
If your testing indicates that you would benefit from additional filtration, use those results to guide your decision rather than choosing a system based solely on marketing claims. For homeowners considering reverse osmosis, Revosmo’s The Ultimate Guide to Reverse Osmosis Systems explains how RO works and what to consider before purchasing a system.
