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Understanding a Drinking Water Test Result
Understanding a Drinking Water Test Result
It's important to learn about the contaminant tested for and what your results mean for your health.
Compare Your Water Test Results
Compare your water test results with established federal or state agency drinking water standards for contaminants in drinking water. Drinking water standards for public water supplies are created by agencies such as the United States Environmental Protection Agency (EPA) or Michigan Department of Environment, Great Lakes, and Energy (EGLE). The Michigan Safe Drinking Water Act provides EGLE the authority to oversee these drinking water standards..
When you compare your results with drinking water standards and health-based values, be sure you understand what these mean and what they were created for, some standards and values are:
- Based on people's health.
- Established not because of health concerns, but to help manage taste, smell, and color of water.
- Based on technology available to treat water for the contaminant.
Each water supply type has different requirements for applying these standards and values:
- Type 1 community public water supplies are required or encouraged to comply with standards.
- Type 3 public water supplies are required or encouraged to comply with some of these standards.
- Private residential wells are not required to follow these standards and values, but are encouraged to use them as guidelines.
Not all labs report test results use the same measurements as the established drinking water values. When you compare your results, it is important to know that these are all equal:
0.1 miligrams per liter (mg/L)
0.1 parts per million (ppm)
100 micrograms per liter (µg/L)
100 parts per billion (ppb)
100,000 nanograms per liter (ng/L)
100,000 parts per trillion (ppt)
Resources Available to Help You!
Be well informed: EGLE's Be Well Informed online water test interpretation tool. The online tool provides some established federal or state agency drinking water values to compare your results with.
Contaminant fact sheets: MDHHS has a series of contaminant fact sheets that can help you understand what results mean for that contaminant and what health risks are associated with each.
To stay up to date with current resources and opportunities being offered through the program, subscribe to the Drinking Water and Health newsletter https://bit.ly/Drinking-Water-Health-Newsletter
To stay up to date with current resources and opportunities being offered through the program, subscribe to the Drinking Water and Health newsletter.
If you have questions, please contact the MDHHS Drinking Water Hotline at 844-934-1315.