Consumers who want to know if their drinking water is safe have an impossible choice. New research shows the quality of at-home water test kits can vary wildly. Emily Kumpel (above), an associate professor of civil and environmental engineering at the University of Massachusetts Amherst, is the principal investigator on the project to develop new TAPP Water-style test kits. She assesses their effectiveness and advises consumers about when they should test their water.
Kumpel recommends that all homeowners test their water—especially if they identify with one or more of these categories. If you have your own well, or if your home is older with old plumbing, don’t wait—act today. This step is particularly key if you’ve been affected by recent climate disasters such as flooding or wildfires. Unfortunately, this study demonstrates that hundreds of at-home water test kits inundate the market. Given the total absence of regulation, there’s a deep concern about their reliability.
Understanding Water Testing Kits
At-home water test kits come in two main varieties: single-parameter tests and multiparameter tests. Many single-parameter tests have a simple, laboratory-like preprocessing step for water samples that improves the accuracy of results. Unlike federal and state government testing initiatives, these kits only cover the detection of one contaminant at a time.
Multiparameter tests are designed to identify several different contaminants at once. As Kumpel explains, these tests can’t even reliably detect the presence of pollutants at low levels — for instance, with iron. Consequently, users can expect to get wildly different results. Some kits will over-report the presence of contaminants and some will underreport.
“These tests might be a good first cut on things, but it’s not necessarily telling you all the information you need.” – Emily Kumpel
Most importantly, Kumpel says test results always need to be interpreted with caution, and this is especially true when it comes to metals. Consumers should know that differences in testing conditions can greatly affect results. Sampling water shortly after it’s had a chance to sit in pipes will yield misleadingly positive results. Samples collected after the home’s plumbing system was flushed consistently represent the opposite scenario.
Factors Affecting Test Results
Timing is crucial when conducting water tests. Kumpel advises homeowners to let their water sit for a while—preferably overnight—before they test it. This approach allows for more reliable sampling. The first draw of water from a tap is often the most revealing. Yet, it often has the lowest measured level of contaminants that could have leached from the plumbing materials.
For people on private well water or connected to municipal systems, Kumpel recommends flushing the tap before sampling. Run your water for a few minutes before taking your first sample. This route, you will obtain a more transparent image of the water quality from the source.
“You want to do what’s called a first draw sample, where you’re getting the very first water that comes out of your system that’s been sitting there overnight.” – Emily Kumpel
Kumpel notes that many people experience concerns about their drinking water quality due to media reports or noticeable changes in taste or appearance. This anxiety has fueled rising demand for at-home, convenient testing kits even with their clear-cut limitations.
The Need for Better Regulation
The unregulated status of at-home water testing kits has sent up red flags among water experts such as Kumpel. She points out that some kits do well in lab settings, but fail when it comes to real-world conditions. This lack of standardization can produce misleading outcomes for consumers seeking to verify their water’s safety.
“It really points to the fact that this is an unregulated space.” – Emily Kumpel
Beyond Kumpel’s personal experience, she understands that many people in the United States lack trust in tap water. This lack of trust frequently sends them seeking solutions elsewhere. She thinks that accurate, trustworthy testing would help consumers by allowing them to substantiate that their water is safe to drink.
“Having access to be able to test your own water and confirm that it is okay—which is the most common result that people would get by testing their water—is a really good thing.” – Emily Kumpel