Water Quality Testing

Most Californians receive their drinking water from a State regulated public water system. Regulated water systems must follow many state and federal laws and regulations intended to ensure the water is safe; therefore, if you receive water from a public water, it is unlikely that you need to independently test your water quality.  Click here to find water quality information for public water systems regulated by the State.

The information below is applicable whether:

  1. You receive your drinking water from a private well
  2. You receive your drinking water from another type of unregulated water source (such as a creek, river, cistern, etc.
  3. You receive your drinking water from a regulated water system, but would just like to confirm whether the piping in your home is impacting your drinking water quality
  4. You are just a concerned customer of a regulated water system

Please note that any water quality testing performed should be done by an Environmental Lab Accreditation Program (ELAP) certified laboratory that is accredited to perform drinking water testing.  For information on ELAP and resources related to laboratory accreditation click here.

Water Quality Testing Resources for Private Domestic Well Owners and other Non-regulated Sources

  • To assist well owners, the State Water Board Groundwater Ambient Monitoring and Assessment Program (GAMA) has prepared a webpage with a wide array of  information for private well owners. Click here to go to the GAMA webpage.
  • For owners of private wells or other non-regulated sources, general information about water quality in your area may be able to be found by contacting your local County Environmental Health Department. To find contact information for your local environmental health department, it is recommended that you do an internet search for the name of the county you are located in, then a comma, and then the phrase “environmental health”, for example:  “Shasta County, environmental health”, or call your local Environmental Health Department.

Who should do the testing of my water quality?

You should test your water quality using a laboratory that is accredited to perform specific drinking water testing by the Environmental Lab Accreditation Program (ELAP). For information on ELAP and resources related to laboratory accreditation please click here.

What should I test my water for?

Drinking water, including bottled water, may contain trace amounts of chemical constituents which may or may not be harmful to your health. For more detailed information on what you should be testing for click here to see the Guide for Private Domestic Well Owners, or click here for the information provided on the GAMA webpage. A list of the ELAP accredited fields of testing (FOT) related to drinking water includes FOT 101, 102, 103, 104, 105, and 106. For current information on FOTs please click here.

How much does testing cost and who is responsible for paying for it?

If you are a private well owner, receive water from a unregulated water supply, or are concerned about the water coming from your tap; then the costs of water quality testing will be your responsibility. Basic sampling can cost from $35 to $400. Hiring an outside business to sample your well and interpret the results will likely cost more. Ask an accredited laboratory from the ELAP for a written cost estimate of exact prices before sampling.

How do I interpret the lab results?

Click here for information on what constitutes unsafe levels of specific contaminants in drinking water.

Tests for Common Water Quality Problems

The Table below outlines several common problems in drinking water and substances for which you can test for. Not every problem and possible cause is a health risk. Less-frequently encountered water quality issues are not listed in the table below; if your particular water quality problem is not listed or for a more thorough discussion of the causes of water quality problems, please contact your public water system or local county environmental health department.

Possible Causes of Common Taste, Odor, and Appearance Problems
Problem Possible Cause
Water is orange or reddish brown High levels of iron (Fe)
Porcelain fixtures or laundry are stained brown or black Manganese (Mn) and/or iron (Fe) can cause staining
White spots on the dishes or white encrustation around fixtures High levels of calcium (Ca) and magnesium (Mg) can cause hard water, which leaves spots
Water is blue High levels of copper (Cu)
Water smells like rotten eggs Hydrogen sulfide (H2S)
Water heater is corroding Water can be corrosive. Very corrosive water can damage metal pipes and water heaters
Water appears cloudy, frothy, or colored Suspended particulates, detergents, and sewage can cause water to appear cloudy, frothy, or colored
Your home’s plumbing system has lead pipes, fittings, or solder joints Corrosive water can cause lead (Pb), copper (Cu), cadmium (Cd), and zinc (Zn) to leach from lead pipes, fittings, and solder joints
Water has a turpentine odor Methyl tertiary butyl ether (MTBE) or other organic compounds
Water has a chemical smell or taste Volatile or semi-volatile organic compounds (VOCs) or pesticides

Helpful resources related to Drinking Water Contaminants:


Still have questions?  Please contact us at SB1070Coordinator@waterboards.ca.gov for help.