Nitrates are chemical units that combine with organic and inorganic compounds. They don't evaporate, don't bind to soil, and are very soluble, so they have a tendency to seep into the ground water. Nitrate is a plant nutrient, and remains in the water until plants or animals consume it. It causes eutrophication (enrichment of water with nutrients), thus stimulating the growth of algal blooms and aquatic vegetation.

     Nitrates are used in fertilizer for agriculture and lawns. It is also found in human livestock waste. Run-off from fields or lawns may contribute to high nitrate concentrations in lakes, rivers, or other bodies of water. Large nitrate concentrations eventually cause an increase in biochemical oxygen demand (not enough oxygen for the aquatic life and vegetation).

    Long-term effects of high nitrate concentrations include diuresis, hemorrhaging of the spleen, and increased starchy deposits. Nitrates are regulated by the Safe Drinking Water Act (1974). Maximum Contaminate Level (MCL) of Nitrates, regulated by the EPA, is 10 ppm.

Nitrate Testing Procedures for Cadmium Reaction Method:

For this test, it is recommended that three samples of water be taken.

1. Obtain a cuvette and rinse it with the water to be sampled.

2. Using the same cuvette, fill it to the first ring.

3. Pour the powder from a NitraVer5 Nitrate Reagent Powder Pillar into the cuvette.

4. Put the lid on the cuvette and shake the contents for one minute.

5. Let the contents in the cuvette sit for 5 minutes.

6. After 5 minutes have elapsed, wipe the cuvette with a clean rag to remove any smudges or fingerprints from the glass.

7. Place the cuvette in the colorimeter.

a. Note: If not done already, place a blank cuvette in the colorimeter for calibration. Calibration is done by pressing the small green button on the colorimeter. It should light and then go off. When the light has gone off, the instrument is ready for testing

8. After calibration, place one of the samples in the colorimeter and close the lid. Be sure that the cuvette is free of fingerprints.

9. Set the Explorer to read green absorbance. The Explorer will take all of the light absorbances and transmittance at the same time. The display will help in recording a paper and pencil value of the absorbance

10. Repeat steps 1 to 10 for the second and third samples.

11. The calibration curve constructed in May of 2005 provides an equation of y=.00273x + .0088 with r=.973. y is the green absorbance and x is the concentration of nitrates in parts per million