Acid rain test results

Acid rain test results

August 21, 2010 - After unsuccessfully attempting to attain information from government agencies about the possibility of acid rain in the Gulf region (caused by evaporation of volatile organic compounds from the millions of gallons of oil and dispersant on and in the water column, as well as from the burning of oil and methane on the surface), we set out on a mission to document precipitation in the area ourselves.

Our first samples come from six locations, two from each state: Florida, Alabama, and Mississippi. The samples were taken over a wide area (approximately 300 miles of coast) to provide variety in our testing. Rainwater pH varied from 5.6 in the panhandle of Florida to 4.8 in more heavily affected Mississippi and Alabama. The pH scale is logarithmic, meaning every degree is the equivalent of 10 times more acidity. So, according to our results, the rain in Gulfport, MS is 10 times more acidic than that in Destin, FL, for example.

We are also working to create a citizens group that will run these tests frequently over a larger area to provide independent data and analysis to compare with any future government findings (EPA releases one report per year per region and has not yet compiled data for the Gulf region). We will also occasionally submit random samples to an independent lab for increased accuracy. If you are interested in getting involved in a citizens’ acid rain monitoring group for the Gulf region, please send an email to judson@sosfla.org.

Background information on acid rain:

What is acid rain?

Acid rain occurs when emissions of sulfur dioxide (SO₂), oxides of nitrogen (NO_X), and evaporation of volatile organic compounds (VOCs) react in the atmosphere with water and oxygen to form acidic compounds. These compounds are then deposited on the earth’s surface in the form of rain, snow, or fog. Prevailing winds can transport acid rain and precipitation over hundreds of miles, even across state and national borders, before they are deposited on the surface.

What is pH?

The pH scale measures how acidic or basic a substance is. It ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic, and a pH greater than 7 is basic. Each whole pH value below 7 is ten times more acidic than the next higher value. For example, a pH of 4 is ten times more acidic than a pH of 5 and 100 times (10 times 10) more acidic than a pH of 6. 

Distilled water has a pH of around 7. Rain water is usually around 5.6. This is because carbon dioxide (CO₂) dissolves into water in the atmosphere to form carbonic acid. Rainwater having a pH of less than 5.6 is considered to be acid rain.

What environmental effects does acid rain have?

Acid rain can cause acidification of lakes, streams and other bodies of water. In fact, many lakes have become so acidic (4.8 pH and lower) that fish cannot live in them anymore.

Degradation of soil minerals from acid rain produces metal ions that are then washed away in the runoff. For example, toxic aluminum ions can wash off into the water supply, and the leeching of calcium from soil can kill trees and damage crops.

In addition, acid rain can accelerate the decay of paints and building materials, including buildings, statues, and sculptures that are part of our cultural heritage.

Image Credit: The Weather Channel