Amundson, Susannah

Critzer, Faith

McCarty, Grant

Wszelaki, Annette

English

University of Tennessee, Knoxville: Trace

University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Commercial Horticulture UT Extension Publications 7-31-2012 SP740-A Good Agricultural Practices Series: Testing Water for Fruit and Vegetable Production Susannah Amundson Grant McCarty Faith Critzer Annette Wszelaki Follow this and additional works at: https://trace.tennessee.edu/utk_agexcomhort  Part of the Agricultural Economics Commons, Agricultural Education Commons, and the Water Resource Management Commons Recommended Citation "SP740-A Good Agricultural Practices Series: Testing Water for Fruit and Vegetable Production," Susannah Amundson, Grant McCarty, Faith Critzer, and Annette Wszelaki, SP740-A , https://trace.tennessee.edu/utk_agexcomhort/52 The publications in this collection represent the historical publishing record of the UT Agricultural Experiment Station and do not necessarily reflect current scientific knowledge or recommendations. Current information about UT Ag Research can be found at the UT Ag Research website. This Production and Management is brought to you for free and open access by the UT Extension Publications at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Commercial Horticulture by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact trace@utk.edu. 1SP 740-AWhy should I test my water?Water is used throughout fruit and vegetable production for frost protection, irrigation, fertigation and protective sprays. Water can harbor harmful bacteria called pathogens, like Salmonella and pathogenic E. coli, which can cause foodborne illnesses. When contaminated water is used in crop production, there is a risk that these pathogens may contaminate produce. Microbial risk is affected by the type and level of pathogens present, type of crop (aboveground crops are at a greater risk than belowground crops), water source (streams and lakes are at greater risk than wells), irrigation method (overhead is at greater risk than drip irrigation), and timing of application and harvest (the longer the interval between the two, the better). Testing and keeping water test records improves on-farm risk assessment and provides assistance for understanding when mitigation strategies should be adopted. What water sources do I test?Any water source used for irrigation, frost protection or pesticide/fertilizer application should be tested. These sources include wells and surface water like ponds, lakes, rivers and streams. If using municipal water, the local municipality or health department tests the water and a copy of test results can be requested from them. Note: Potable or drinkable water should be used for all applications on produce after harvest.  When do I test?Well water should be tested at least twice a year: 1) at the start of the season and 2) at peak use. Microbial pathogen levels in surface water vary and are affected by many factors including time of year, flow rates, climatic events and upstream activity. For this reason, it is recommended that multiple tests be taken throughout the season to get an average microbial analysis. Testing should be done at least three times a year: 1) at the start of the season, 2) at peak use, and 3) at harvest. If using municipal water, a copy of test results can be requested from the local municipality or health department. You should have the current year test results on file.What do I test?A typical food safety agricultural water test should screen for quantified generic coliforms of E. coli bacteria. Other parameters that can be useful for both general production and food safety include conductivity, turbidity and pH. 1. Coliforms: Testing should include analysis for    quantified generic coliforms of E. coli. Results should   be reported as a number (colony count or MPN — Most   Probable Number per milliliter) and not just as the    presence or absence (P/A) of bacteria.2. Conductivity: Conductivity is the measurement of the   ability of water to conduct an electric current and an    indicator of the salinity or mineral content of water.    Great changes in conductivity readings also can be an    indicator of pollution. Good Agricultural Practices Series Testing Water for  Fruit and Vegetable Production Susannah Amundson, Extension Assistant, Department of Plant SciencesGrant McCarty, Graduate Research Assistant, Department of Plant SciencesFaith Critzer, Assistant Professor, Department of Food Science and TechnologyAnnette Wszelaki, Assistant Professor, Department of Plant Sciences23. Turbidity: Turbidity is a measurement of the     suspended particulate matter in the water that interferes   with the passage of a beam of light through the water.    Materials that contribute to turbidity are silt, clay,    organic material or microorganisms. The higher the    turbidity of water, the greater the surface area of    particles for potential bacterial growth. 4. pH: Testing pH gives a measurement of the hydrogen    ion concentration in water and indicates the relative    acidity or alkalinity of your water. Test results will    range from 0.0 to 14.0, where pH 7.0 is neutral, less    than 7.0 is considered acidic and greater than 7.0 is    considered alkaline, or basic. The purpose of testing    water pH for food safety is to provide a broad     monitoring of the source.  How do I take a sample?  These are general guidelines. If the testing lab you plan to use has a specific protocol make sure to follow it.  1. Contact the testing laboratory and have them send you a  water sampling kit. Contact information can be found    below. 2. Supplies to have on hand (Figure 1):  • Marker for labeling bottles.  • Sampling bottles — two for each source being tested.     (One for coliforms and one for other water parameters.     These will be part of the sampling kit received from      lab.)  • Cooler.  • Ice or ice packs.  • Shipping labels, if mailing to lab.  • Tape, for securing any labels.  • Zip-close bags.  • Sampling pole (optional, helpful for surface water      sources). 3. Locate the best sampling area. 4. Samples should be taken as close to point of use as    possible. This sample location can be directly from    irrigation equipment in the field or from the water    source itself. If taking a sample from the water source,   make sure it is a representative sample by choosing an   area that is: 1) near where the pump draws the water, 2)   clear of debris and vegetation, and 3) undisturbed.  5. Write farm name, water source, date and time of sample   on the bottle or the bottle cap (Figure 2). 6. Remove bottle lid. Do not touch inside the bottle or cap   to avoid contamination. If the source is surface water    (stream, pond, river, etc.), it is best to submerge the    bottle before removing the lid to prevent contamination   from debris on the water surface. 7. Fill bottle with water.  • If taking a sample from irrigation equipment, make      sure to 1) let the water run at least one minute before     collecting your sample and 2) not allow the lip of the     bottle come in contact with the equipment.  • If sampling surface water, take a sample near the      middle of the source or several feet from the side of      the river, stream or pond. Also, take the sample well   Figure 1. Water sampling supplies: cooler, ice or ice packs, sampling bottles, marker, zip-close bag and tape.Figure 2. Sampling bottle properly labeled with name, date, time and type of water source.3   below the water surface, as deep as possible without      scraping the bottom of the source. Take care to NOT      collect floating debris or scrape the sides or bottom of     the source while sampling — all of which may      contaminate the sample. 8.   Replace lid. 9.   As a precaution, double check the bottle label to          ensure accuracy. 10. Place bottle in zip-close bag. 11. Immediately place in cooler on ice or ice packs.      Sample placement in the cooler must be done within      15 minutes of collection. 12. Deliver samples to the lab within six hours of      collection. Notify the lab a day prior to delivery, so      they can be prepared to receive your sample. If      sending your sample to the lab instead of delivering it     in person, be sure to ship the sample overnight.  Examples of laboratories in Tennessee that can run all the tests listed above: East:Microbac Labratories505 East Broadway Ave. Maryville, TN 37804-5744 865-977-1200 Middle:Dan Dodson Lab Manager TTU Center for the Management, Utilization and Protection of Water Resources Box 5033 Cookeville, TN 38505-0001 931-372-3061 ddodson@tntech.eduWest:A&L Analytical Laboratories Inc. 2790 Whitten Road Memphis, TN 38133 800-264-4522/ 901-213-2400 support@allabs.comPlease contact the lab for their current fee schedule and sampling protocol.For information on interpreting water test results, please review UT Extension publication SP 740-B Interpreting Water Quality Test Results for Fruit and Vegetable Production. For more information and additional food safety resources, visit:  http://vegetables.tennessee.edu/food_safety.html.4Programs in agriculture and natural resources, 4-H youth development, family and consumer sciences, and resource development.University of Tennessee Institute of Agriculture, U.S. Department of Agriculture and county governments cooperating.UT Extension provides equal opportunities in programs and employment.SP 740-A    R12-5110-084-011-12    12-0172    1.5M    06/12

SP740-A Good Agricultural Practices Series: Testing Water for Fruit and Vegetable Production

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SP740-A Good Agricultural Practices Series: Testing Water for Fruit and Vegetable Production

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