How Do I Test My Well Water in a Lab?
Getting your well water tested in a professional lab might seem scary, but it's much easier than you think. It’s extremely helpful and definitively superior to inaccurate home test strips.
How does laboratory well water testing work?
No matter what you're testing for (routine well checkup or known contamination issue) the process of testing in a lab is the same.
- You receive a sampling kit and sample at home.
- You ship your water samples to the lab.
- The lab analyses your samples and prepare your report
What should I test for in my well water?
There are actually thousands of parameters (a.k.a. “analytes” or “contaminants”) to test for. Reach out to your nearest water quality lab to ask which chemicals and microbes they think are appropriate for your situation.
While there are indeed thousands of other natural and synthetically produced chemicals, radionuclides and microbes to consider testing for, most of them won’t apply to you.
Basic Well Water Test Parameters
- General chemistry
- Metals, minerals, other inorganics
- VOCs (Volatile Organic Compounds)
- Coliform bacteria and E. coli
Consider potential contamination sources nearby your well. Dumps, industry and farming can lead to hazardous chemicals leaching into your water. Some do not change the taste, smell or look of your water so testing is the only way to know.
What's in a well water sampling kit?
These are the typical components of any well water sampling kit you’ll encounter. Some tests may also include specialized components such as ice packs to keep the sample cool.
You'll receive detailed instructions with your well water sampling kit. The instructions will tell you how to collect your sample. Read your instructions carefully before and during testing!
Your sampling kit will include one or several sampling containers (glass or plastic). Some may include preservatives to keep the sample stable.
Sample Information Card
A Sample Information Card and/or Chain of Custody Form should accompany every sample. You will use this form to record details about the sampling method, date, time and location of your sample.
Free or Paid Return Shipping Labels
If you ordered your water test kit online, be sure to save the box and check if a shipping label is already included so you can easily drop it off for shipping, and often save a lot of money too.
How to collect your well water sample
The water sampling itself is usually straight-forward, but remember to follow your instructions carefully. The decisions you make during sampling can influence your result!
Choose WHERE to sample
Most water testing kits will be for a single location. While there may be many bottles or vials, never put water from different sources in them, because the different bottles test for different contaminants or serve as important back up samples.
The location you chose to collect your sample will influence what your results mean. Sampling directly from the well head will tell you about your well. Sampling from your kitchen faucet will tell you about the well PLUS your plumbing and any other fixtures.
If you have a water filter you need to decide whether to test the filtered or unfiltered water. Or you can buy two test kits and run a filter performance test, analyzing before and after the water filter.
Choose WHEN to sample
The time of day you collect your water sample can also impact your results.
Certain plumbing-dependent metals like lead will be most likely to show up after water has sat in the pipes overnight. For sampling bottles labelled for metals testing, you may choose to collect them first thing in the morning. This is generally called a first draw sample.
Dissolved gases and other VOCs are more likely to diffuse out of the water if they sit in the plumbing for a long time. To capture whether your water has VOCs (or radon, for example) it’s often better to let the water run for a few minutes first. Then you know you’re grabbing fresh sample water from your well, which has had less time to interact with your plumbing.
Best Practices When Collecting Your Water Sample
- Do not rinse out the inside of the containers.
- Do not touch the inside of test vials or their lids.
- Remove any aerators or other faucet attachments from sample location, if possible.
- Collect all your samples from the same source (e.g. faucet or well-head).
- Use a low flow when drawing water.
- Close lids tightly! You don't want them to spill in transit.
You might receive separate packages from the lab. If you do, then take care to not mix up the contents of the packages.
Return the samples to your lab
Remember to either drive or ship your samples as soon as possible after collecting your samples. If you need to wait before driving or shipping, try to keep your samples refrigerated.
If you’re driving to the nearest certified environmental testing lab, it helps to know their receiving and closing hours. If you're testing with Tap Score you'll find a pre-paid return label included. Give it to your USPS postal service employee or drop it off at your post office.
Being prepared helps you avoid any unforeseen issues.
Don't forget to include your sample information card or chain of custody form with your sample!
How do I interpret the results of my water test?
Once the lab receives your water sample they'll analyze it according to the testing methods you asked for. The results will show you the concentrations of contaminants in your sample.
This General Water Chemistry 101 guide is helpful to have on hand.
How do I know if my water is safe to drink?
The EPA Drinking Water Regulation govern community water systems (water utilities). While these regulations have no impact on private well water, they are a good place to start when interpreting the health risks of your results.
The EPA’s primary drinking water standards set legal limits for over 100 contaminants–these are called Maximum Contaminant Levels (MCLs). They also provide Maximum Contaminant Level Goals (MCLGs)–thresholds based on health-based toxicology research. The difference is that MCLGs are purely health based whereas MCLs also factor in an economic assessment.
Compare these limits to your own water results report to get an idea of how well your water quality stacks up. Most labs will indicate if your sample exceeds an MCL, but you want to evaluate your results against MCLGs to know if there is a health concern. If your concentrations of some analytes exceed the health levels posted by the EPA then you should filter your water quality.
What are other concerns around my well water?
There are also other health standards beyond EPA federal guidelines.
Talk to your lab contact to gain for more information on the other kinds of health and aesthetic thresholds that might matter to your drinking water. A common and highly regarded source is California’s Office of Environmental Health Hazard Assessment’s Public Health Goals.
You or a family member might have health conditions or concerns that require you to treat water quality for contaminants NOT covered by the EPA. Or you might want to bring concentrations of lead and arsenic, for example, to even lower concentrations than the levels required of public water systems. Consult your doctor and health experts to know what levels are safe for your family.
Also consider any pets you might have. Particularly small animals and aquarium fish are vulnerable to contaminants.
With over 80,000 chemicals circulating our economy and environment there are contaminants that are not (yet) regulated by the EPA. Many are increasingly detected in water and might pose a threat to human health. Many are also just harmless or not in the drinking water at all!
Some commonly investigated chemicals, often referred to as 'emerging contaminants', which are not regulated:
How much does it cost to test well water?
The cost of lab testing is based on the contaminants you test for. You'll find tests for as little as $60, but those will not give you a thorough analysis of how safe your water is to drink.
A good overview of your well water quality will run around $200-$300, but it's possible to spend $2,000 for extremely thorough tests. Talk to an expert first to determine if that's necessary and choose the test that fits your budget.
How can I get my well water tested for free?
Your local or state Health and Human Services Department may occasionally refer you to a certified environmental laboratory. Most such testing though is very narrow and might only include testing for coliform bacteria and/or lead. Some communities offer 'Test your well' events where you can get a free well water screening.
In general, we do not recommend "free" tests conducted by filtration companies.
Can I use at-home test kits for my well water?
You will find cheap water test kits at just about any hardware store. While these can work well for quick readings of a few contaminants (like free chlorine, pH, hardness), such at-home testing strips have major flaws you should be aware of before you buy.
- Most DIY strips and kits are notoriously inaccurate.
- DIY tests don’t test for enough contaminants.
- Test strip results might be instant, but can be confusing to interpret.
- Test strips won’t include the same professional support as you’d get from a scientific laboratory.
How often should I test my well water?
The Federal US EPA suggests you test your private well a minimum of once per year. Test more frequently if your well is shallow or if you have a surface water source.
If your well’s water quality results are regularly performing safely, then you can consider cutting back to a biannual test or a test even every 3-5 years. It depends on your risk tolerance, after all private wells are entirely unregulated.Do not wait to test if your water suddenly changes color, taste or odor.
What is the best water test for my well?
Every well is unique; choose a test that is right for your situation. Just as there are no perfect filters there is no perfect test for everyone. The best practice of all is to test annually and be smart about the maintenance of your well to ensure the water you drink is not incurring any damage to your long-term health.
What is the best treatment system for well water?
Always, always, always get a water test done before you spend money on any water filtration or disinfection system.
After you review your home’s water quality report, only then can choose an appropriate filter and treatment system accordingly. If you have questions, your local treatment expert or online resources like WaterFilterGuru.com can help. Tap Score also has experts available for unbiased recommendations. As a bonus, all Tap Score Reports come with personalized treatment suggestions for your results.
For general questions about water treatment, these resources can be helpful: