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Agricultural Testing Services: Water Testing

Water Testing for Human Consumption

For information on testing water for human consumption in Oklahoma, contact the Oklahoma Department of Environmental Quality. Individuals living in Texas can contact the Texas Commission of Environmental Quality. Most Cooperative Extension Offices can provide information and supplies needed for this type of testing.

Reasons for Water Testing

Water analysis indicates:

  • Suitability of water for use in irrigation systems.
  • Suitability of water for livestock, poultry, fish, aquatic plants and other aquatic organisms.
  • Suitability of water for pond fertilization or treatment with alum.
  • Suitability of media for container-grown plants through pour-through leachate.

Collecting Samples

Take a sample of water to be used for agricultural purposes under the conditions in which the water will be used. You may want to take samples at several processing stages or time periods.

Sample containers should be clean and made of plastic. For complete analysis, a minimum of half a pint (8 ounces) of solution is required. Before filling the container, rinse it thoroughly with the solution being collected. Fill the container completely and screw the cap on tightly. Label the container with your name and the sample identifier.

  • Wells – Before sampling water from new wells or from wells recently treated with chemicals, run water for one to two hours. Running the water five to 10 minutes before sampling is usually sufficient for established wells. Longer times may be necessary if wells have not been used recently.
  • Rivers or streams – Sample from the middle of the stream at mid-depth. Avoid collecting surface or bottom residues.
  • Lakes or ponds – Take a sample where the water is at least 3 feet deep. Use a boat, tube, life vest, dock or a stick to collect the sample. Avoid stirring up the silt. After rinsing with pond or lake water, turn the container upside down and go down about 1 foot (up to your elbow) and then turn it over underwater to fill it. Bring the container up to the surface and cap it tightly with a plastic lid. Information about water quality in ponds is available at:
    Let's Clear the Waters
  • Hydroponic systems – Flush lines sufficiently to ensure that the sample is representative of a thoroughly mixed supply solution.
  • Nutrient solutions – Sample after diluting the nutrient concentrate for application and making any other necessary adjustments. The sample should have the same concentration as the solution being fed to the plants.

Packaging and Mailing Information

Water Sample Entry Form

Complete all appropriate blanks on the information sheet(s) and write legibly. Be consistent from year to year in listing name, farm name and/or address. Also, check to make sure the sample ID on the form corresponds to the one on the water sample. Testing takes about seven to 10 working days to complete from the time we receive your shipment.

Place information sheets inside the shipping container with the samples and keep a copy for your records. It is a good idea to place information sheets inside a sealed plastic bag to keep them clean and legible in case your sample bottle leaks.

Do not send cash or check. When you receive your test results, you will receive an invoice from our contract laboratory for testing analysis. Servi-Tech Lab testing cost information is located in the Test Analysis Pricing Sheet.

Water Quality Interpretation

For assistance in interpreting water quality results, please refer to the Noble Research Institute Livestock Water Guidelines, Irrigation Water Guidelines, Noble Research Institute consultant or a county Cooperative Extension agent.

Some parameters such as pH and dissolved oxygen in surface waters (ponds, lakes, rivers and streams) should be measured on site because diffusion and biological activity in water cause these parameters to change after a water sample is collected.

For more assistance, please contact the Noble Research Institute Agriculture Helpline at 580-224-6500.