A pH test measures the alkalinity or acidity concentration in water. A pH of 7 is neutral, below 7 is acidic, and above 7 is basic or alkaline. Acid rain, from auto exhaust or coal-fired power plants, causes a drop in the pH of water. Pollution from accidental spills, agricultural runoff and sewer overflows can also change the pH. Buffering capacity is water's ability to resist changes in pH, and is critical to the survival of aquatic life. The limestone soils of Central Texas act to neutralize these acids and often result in a more basic pH. While young fish and insect larvae are sensitive to a low pH (acid), extreme values on either end of the scale can be lethal to most organisms. Expected levels: 6.5 to 9.0
The levels of pH:
0-4.0 aquatic life is severely stressed
4-4.5 few fish and invertebrates can survive
4.5-6.5 acid-tolerant invertebrates and fish can survive
5.0-9.0 suitable for human consumption
6.5-8.5 suitable for most aquatic animals
6.5-13 suitable for most aquatic plants


Chicago River

6.1+/- 0.2 (6.0-6.5) –ph strips
7.5 +/- 0.4 (7.0-8.5)
7.8 +/- 0.2 (7.4-8.5)- meter

Clear Creek(Chamber Creek)

(Clear Creek) strips
Mean: 7
Standard: 1.5
Range: 3-9

(Chamber Creek) strips
Mean: 7.8
Standard: 1.4
Range: 4-9

(Clear Creek) meter
Mean: 7.5
Standard: 0.4
Range: 7-8.5

(Chamber Creek) meter
Mean: 7.6
Range: 4-9

Sava River

Mean of pH results for trial 1: 8.2                       Mean of pH results for trial 2: 7.6                      Mean of pH results for trial 3: 7.8

Ohio River

The pH of the Ohio River is 6