Web sites for pH Data Activities:

1. What is the pH of rain in the US? Why might it vary?

2. What are the pH's of Minnesota lakes? How does pH vary with temperature, season, and lake depth?

What questions do these lake data raise? [Click on a lake, Color Mapper , and Surface Trends - then play around from there.] The homepage for this "Water on the Web" (WOW) site is here.

3. What are lake pH's in the northeastern US (Adirondacks)? How does this compare to MN lakes? Use general info from the Adirondacks Lake Survey Corporation, and their chemistry/nutrient/pH data on Lake Willys and Big Moose Lake.

4. What about bog soil/water pH? Check out 2 bogs in Washington state, one with some "urban disturbance". This relates to a bog we'll sample at Long Lake, MN. Explore the site for information and report back what you learn about bogs, their pH, nutrient levels, and general conditions.

5. What is the pH of a calcareous fen and what controls it? This page has pH, conductivity, and ion data for a calcareous fen in Millbrook Marsh in Western Pennslvania. You can also explore data (pH, nutrients, dissolved O₂, etc. ) for water quality at the same calcareous fen.

Some definitions:

• What is pH? It measures the amount of the chemical species H₃O⁺ (often abbreviated as H⁺, the proton).
  • pH = - log₁₀ [H₃O⁺]
• What is alkalinity? Scroll through article to find the definition.
• What is acid neutralizing capacity (ANC)?
• What is carbonate alkalinity?
• What is buffering capacity? Soil or water with a large buffering capacity resists change in pH when either acid or base are added. Notice that this is not quite the same as alkalinity, which only measures the total amount of bases (solute) that can neutralize acids. Watch out for lots of incorrect usage of this term on the web!!

Some simple Acid Rain Experiments:

Acid Rain experiments with SO₂ and NO in a petri dish, modified from the ChemConnections module on acid rain

Other sites of interest:

• A recent (July 8, 2002) MPR news story about how bogs and fens might sequester or release carbon with global warming!
• Links to famous Little Rock Lake in WI, the hourglass lake which is the site of landmark EPA acid rain experiments that started in 1984 (Andy told us about these experiments!). This is where they found sulfur-reducing bacteria that consume acid and convert sulfate to sulfide. These reports are mostly about the recovery of the lakes after acidification.

  • University of Wisconsin News Release, Aug. 11, 2000.
  • Science Daily report on Aug. 23, 2000.
  • Daily University Science News report on June 13, 2001.

• EPA site on acid rain in the US.
• A publication titled "Wisconsin's Sensitivity to Acid Rain: The Role of Geological Materials and Soils", from the Department of Agricultural Journalism, University of Wisconsin- Madison.
• Effect of acid rain on aquatic organisms other than fish.
• EPA on the effect of acid rain on lakes and streams.
• Long Lake Conservation Center web site.
• ChemConnections module on "Soil equilibria: What happens to Acid Rain?" Check out page with external links on acid rain.
• Wisconsin Department of Natural Resources (DNR) site on acid rain.
• Acid rain in Canada.
• Acid rain FAQs from Canada web site.
• A little reading on bogs and calcareous fens from the USDA Forest Service (Northeastern Area).
• Lake Access data for Minnesota and a few other US lakes- lots of data (sister project of WOW, above).

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This page is created and maintained by Tricia A. Ferrett.
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