The conventional wisdom is that you should test your water once a year. This is simple enough as a general rule, but it doesn’t cover all kinds of situations that should prompt you to test your water more often! In this post, let’s explore the basics of water testing and what should encourage you to test your water more often.

Public Water System Testing

Let’s get this out of the way first—if you don’t have a well, and you’re purchasing water from the municipal water district, you’ll get a report of testing each year with your bill. This is the Consumer Confidence Report, and you can expect to see it once a year in the summer. It’ll tell you about the quality of water over the last year.

Private Water System Testing

There are different types of tests that you can run on your well. Some home test kits will show you a few different kinds of possible problems at the same time, but more rigorous tests should be left to lab professionals. Sometimes you can get a trained technician to collect samples, improving the quality.

Test for hardness if you find a residue with the well, and if your plumbing contains lead you should be testing for that. Common bacterial contaminants include coliforms and E. coli (which is a coliform). These bacteria can cause digestion problems. Other contaminants that you should test for include nitrates and volatile organic compounds (VOCs). VOCs can be related to fuel and industrial waste.

When to Test Well Water

Once Annually

Even if nothing materially changes in your situation, you should still have your water tested once a year. Slow decay and breakdown of well components can subtly shift the composition of water without bringing about changes in color or taste.

Whenever You Notice a Change

It should go without saying, but if your water suddenly takes on a new color, taste, or smell, you should immediately test it. Many people think that this is a foolproof system. But you should never rely on your senses, for a couple of reasons.

First of all, there are plenty of harmful chemicals and bacteria which won’t change the color or taste. Second of all, we tend to get used to slow changes in our water without noticing that they’re happening. If the color slowly changes over time you’ll probably get used to it before noticing there’s a major difference.

After Changing or Repairing Parts on the Well

If you replace pipes or install a new pump or casing, it’s a good idea to test the water. Any change to the system of your well can introduce new contaminants that you weren’t aware of.

If There is a Damaging Event

In the case of a storm, chemical spill, or fuel leak you should get your well tested right away. Damage can occur to the well and allow additional contaminants into the system.

Pregnancy and Bringing a New Baby Home

Nitrate is one of the more common contaminants of groundwater, especially in rural areas. You should always test for this if someone pregnant is drinking the water or if you’ve brought a new baby home. Nitrate in water cannot be seen or tasted, but it can be really damaging in high doses. While there usually isn’t enough to harm an adult, lower levels are enough to harm babies. Nitrate changes the way that the blood carries oxygen, and can contribute to blue baby syndrome.

Pay special attention to testing for nitrates during or after a lot of rain. Rain can introduce higher levels of nitrate into your water system.


So testing your water once a year is the minimum. But if anything changes in your water system or the environment, you can use a targeted test to ensure your water is still safe.