The negative logarithm of the hydrogen ion concentration or activity of a water solution. Used for expressing both acidity (pH less than 7) and alkalinity (pH greater than 7), with 7 considered neutral.
Explanation of common water properties including temperature, pH, specific conductance, turbidity, dissolved oxygen, hardness and suspended sediment for students and general public.
Educational site for elementary school students on the properties of water with links to a true/false quiz, common water measurements, pH, and water facts.
Maps and explanations of continuous real-time data collection methods and results, including water temperature, turbididty, specific conductance, dissolved oxygen, pH, and stream discharge values.
U.S. Department of the Interior |
U.S. Geological Survey