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How do you know if your land is contributing to downstream water quality problems or if the management practices you are using are effective? This section provides information on techniques you can use to assess your water quality.
Installing or using a water quality protection practice does not guarantee that water quality is actually protected. One of the reasons for this is that not all practices are equally effective in every location. Variation in topography, rainfall, management, soils, and other site-specific factors can have a significant effect on the effectiveness of installed practices. It becomes even more important to know how effective a practice is if your property drains into a waterbody that is listed as "impaired" on the State Water Resources Control Board's 303(d) list of impaired waterbodies.
Before you can begin to assess the effectiveness of your installed practice you should first list the pollutants that you are addressing with the practice. For example, in the case of a sediment basin being installed to capture sediment and keep it from being carried off the farm, the basin's effectiveness can be obtained by estimating total potential soil loss and then comparing that value to the sediment trapped by the basin. If the pollutant of concern were an old-generation, persistent pesticide such as DDT, then we would expect that the sediment basin would not be as effective. This is because sediment basins are designed to settle out sand and some silt sized particles but rarely settle out significant amounts of clays sized particles. It is the clay-sized particles that would be associated with the DDT and since the basin does not effectively retain them, most of the DDT would be released downstream.
Below is a list of water quality threats and links to some of the techniques for assessing the conditions in and around your property. This is only a partial list and a more comprehensive list can be obtained from Terry Hall, Water Quality Specialist with the NRCS (see Who You Can Work With section).
Water Quality Tests and What They Measure
| TEST | WHY MEASURE IT? | HOW TO MEASURE IT |
| Ammonia | Toxic levels of ammonia can kill fish and other aquatic organisms. Water temperature and pH strongly influences the toxicity of ammonia. |
Use Ammonia Test Kit or Ammonia Meter |
Low levels of dissolved oxygen affect the growth and development of aquatic plants and animals. |
Use Dissolved Oxygen Test Kit or Meter |
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| Nitrate | If there is enough phosphorous available, then high concentrations of nitrates will result in an increase in algae growth. |
Use Nitrate Test Kit, Meter, or Test Strips |
pH affects many chemical and biological processes in the water. |
Use Meter or Litmus Test Strips |
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| Phosphorus | If there is too much phosphate present, algae blooms may develop which later could lead to the depletion of dissolved oxygen. |
Use Phosphate Test Kit, Meter, or Test Strips |
| Salinity/ Conductivity | The level of salinity in water is often critical to the survival of many aquatic plants and animals. |
Use Alkalinity (chloride) Test Kit or TDS/Conductivity Meter. |
Aquatic organisms have upper and lower temperature limits. Temperatures outside these limits will affect the health of those organism. |
Use alcohol-filled thermometer if possible |
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| Turbidity/ Sediment | Sediment can carry pollutants that bind to soil particles. It can also negatively affect fish health and spawning habitat. |
Use Imhoff Cone or Turbidity Meter |
To find out what the results of your measurements mean and whether the water quality is acceptable see What the Numbers Mean.
To learn where to buy and how much to pay for monitoring test kits see Purchasing Test Kits and Other Equipment.
Some other fact sheets are available below:
- UCCE Short Course Fact Sheets: http://waterquality.ucanr.org/links.htm
Water Quality Tests
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| Test for salinity at the wellhead or any area where water collects (tailwater ditch) or leaves your property. You may also want to test your runoff or a stream section above and below an installed conservation practice.Test your water at least twice per year (6-month intervals). If testing runoff from a field wait until field becomes saturated before taking a sample from runoff. You can measure conductivity using one of the following techniques: |
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| Rapid decomposition of organic matter, high ammonia concentrations, high air temperatures and lack of turbulence all contribute to lowered dissolved oxygen levels. Conduct your test in mid-stream, making sure to sample in the middle of the water column. Remember to routinely take your samples at the same time of day. You can measure dissolved oxygen concentrations using one of the following techniques: |
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| Collect your sample “Above and Below” a potential source. For example, take your samples from a stream above an area where water leaves your farm, and again below the runoff area. If a stream does not flow through your property you can sample anywhere water leaves your farm (e.g. sample the irrigation water at the wellhead and again as it leaves your property as runoff). You can measure nitrate concentrations using one of the following techniques: |
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| An additional technique for assessing nutrients in general is by performing a nutrient budget. This technique is were you essentially take into account all nutrient inputs and subtract from that sum, the sum of all nutrients removed from the field. The goal is to put on only as much as the crop needs. This would leave fewer nutrients available in the field that would be susceptible to losses such as leaching and runoff. |
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| There are mainly two methods for assessing pesticide loss. One method is to collect runoff samples and send them to the laboratory for analysis and the other method is to assess the risk of loss based on usage information and other site specific farm information. If collecting samples, Collect your sample "Above and Below" a potential source as you would for Nitrates. |
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| You should also test above and below any point where water leaves your property and enters a waterbody. Measure pH once per month if livestock present. Since aquatic organisms are sensitive to pH, especially during reproduction, you may wish to measure pH once per week during the spring and summer months. Note that waterbodies with higher temperatures have slightly lower pH values. You can measure pH using one of the following techniques: |
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| Since phosphorous enters surface water usually associated with organic matter (dead plants, animals and animal waste), attached to soil particles or through detergents and fertilizers, you will want to test above and below any waterbody where there is a livestock confinement area, fertilized field or installed management practice. If this is not applicable, conduct your test anywhere water leaves your property. Test for phosphate during your scheduled irrigation activities andduring the first rain event following the application of fertilizers. You can measure phosphorus concentrations using one of the following techniques: |
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| Soil erosion is the process by which the land surface is worn away by the action of wind, water, ice and gravity. The process of soil erosion involves detachment of sediments from the soil mass, transportation, primarily by flowing water or wind, and eventually deposition of sediment. There are four main ways to obtain information about erosion. |
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| You should test for change in stream temperature anywhere ‘above and below’ an area where runoff occurs. If you have a stream running through property you may want to take a temperature reading one-half mile above and below your property line and compare those readings with that on your property. Remember that warmer water holds less oxygen so if you also test for dissolved oxygen, you should see a correlation. Also, keep in mind that ammonia levels increase with increasing temperature. You can measure temperature using one of the following insturments: | ||||||
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