Calculate Chlorine Demand for Safe Drinking Water: A Step-by-Step Guide

One way that diseases such as typhoid, hepatitis and cholera become so prevalent in certain communities is through drinking water. The micro-organisms that make up these diseases multiply and travel in water, and can sometimes get into the public water supply. To improve the quality of the water and kill these micro-organisms, chlorine is often added to water. You can test the chlorine loading in your drinking water using a diethyl para-phenylene diamine (dpd) indicator test.

Things You'll Need

• Diethyl para-phenylene diamine indicator test

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Instructions

• 1

  Place the tablet that came with the dpd indicator test in the test chamber, usually indicated "a."

• 2

  Fill the test chamber with drinking water.

• 3

  Fill the control chamber of the dpd indicator test with drinking water. This chamber is usually labeled "b." Do not add a tablet to this chamber.

• 4

  Wait a couple of minutes for the test to work.

• 5

  Look at the color of the water in the test chamber and compare it with colors on the side of the dpd indicator test. Ideally, the chlorine loading should be at 0.3 to 0.5 milligrams per liter.