Total dissolved solids (TDS) refer to the total amount of salts, minerals, metals, and other particles that are dissolved in water. High TDS levels in water can affect its quality and can impact the taste, odor, and appearance of well water. However, it is not considered a health hazard.
What are the effects of TDS in well water?
Taste: Funny or salty taste
Increased corrosivity: High TDS can make the water more corrosive, which may lead to problems like leaching of lead from pipes or fixtures.
Formation of scale: When TDS includes high levels of dissolved minerals such as calcium and magnesium, it can lead to the formation of scale in pipes and appliances, reducing their efficiency and lifespan.
When should I test for total dissolved solids in my well water?
The USEPA has set a secondary contaminant level for TDS at 500 parts per million or milligrams per liter. A water test will provide information on the levels of TDS in your water. To ensure you are protecting your family’s health, we have developed a set of recommendations for testing that are provided in our article, "What do I need to know about sampling my well water?" , that includes total dissolved solids. When testing your well water you will very rarely be testing for only one thing, like TDS, and instead testing for a suite of constituents that are important to identify if in your drinking water.
What treatment should I use if there is TDS in my well water?
How do I remove total dissolved solids from my water?
Once you test and have decided to treat your water to remove TDS, the Minnesota Department of Health has developed the Home Water Treatment Guide that covers treatment for any common constituent in well water. The most important advice we can provide you is if you are going to add treatment to your home water system, be sure the treatment device has been certified to remove TDS by an independent third-party certification organization.
Where can I get local help and information about iron in my well water?
Contact your local health department – They can help you interpret your sample results and may have information on the best treatment options for your situation. If they personally aren’t able to answer your questions, they will know who to contact who will be able to help you, likely at your state health department.
Contact a water treatment professional - we would recommend contacting a water treatment professional who has been certified through the Water Quality Association’s Professional Certification Program.
State or Federal Geologic or Water Resource Agency – they may have completed field studies of your area or collected samples from water wells to map and understand the water quality in your state. In addition, they may house water well logs, including yours, or be able to provide additional information about the aquifer your well is getting water from.
Consult your well driller or drilling contractor – the contractor that drilled your well, and other local contractors, may be aware of the water quality issues nearby including high iron, and might have worked with other well owners in your area to solve this issue .
Research online – you should be inquisitive; it will help you significantly because there may be great information available online. Use search terms like “my state (CA, ME, IL, etc.) water well logs”, “my state groundwater quality”, or “my state well water quality”.
Contact us directly – if these other local sources don’t work out for you, we may be able to help. We may be able to provide direct assistance, and/or direct you to a technical assistance provider in your area who can help answer your questions (free service funded by USEPA).
Additional Resources
Farrell-Poe, K., L. Jones-McLean, and S. McLean, Well Water Testing and Understanding the Results, April 2011, Arizona Cooperative Extension.
TDS and pH. Safe Drinking Water Foundation.
Want to learn more about your private well and how to care for it?
Sign up for the free 10-week email course from PrivateWellClass.org. The class is a project of RCAP and the University of Illinois, with funding from USEPA.
Not finding the answer you need?
Send us a message in the chat or call us at 1-866-945-0699.