How to Measure for Acidic Deposition

Rainwater is typically a little acidic, because atmospheric carbon dioxide dissolves in the water to form carbonic acid. According to the EPA, a normal pH for rainwater is about ~5.6 or so. In many areas, however, the presence of pollutants like nitrogen dioxide acidifies rainwater so it has a much lower pH -- sometimes as low as 4.3. This phenomenon is called acid deposition or acid rain. You can measure the pH of rainwater in your area by collecting a sample and testing its acidity with a pH meter.

Things You'll Need

• Clean dry plastic bucket
• Calibrated pH meter

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Instructions

1. • 1

     Keep your bucket covered until the rain starts, then take it outside.

   • 2

     Bring the bucket back inside once it's half-full or just before the rain stops -- whichever happens first.

   • 3

     Remove the pH meter from the buffer storage solution and insert the tip into the water sample. Record the pH reading. This will give you a sense of the acidity of your rainwater.