Answer:
Step-by-step explanation:
Dissolved oxygen (DO)
The DO test measures the amount of oxygen dissolved in the water. Oxygen is essential for both plants and animals, but high levels in water can be harmful to fish and other aquatic organisms.
Water temperature
Aquatic organisms are dependent on certain temperature ranges for optimal health. Temperature affects many other parameters in water, including dissolved oxygen, types of plants and animals present and the susceptibility of organisms to parasites, pollution and disease.
pH
A pH test measures the alkalinity or acidity of water. A pH of 7 is neutral, below 7 is acidic and above 7 is basic or alkaline. Acid rain, from auto exhaust or other pollutants, causes a drop in the pH. Pollution from accidental spills, agricultural runoff and sewer overflows can also change the pH.
Escherichia coli (E. coli)
E. coli is a fecal coliform bacteria that comes from human and animal waste. The Environmental Protection Agency uses E. coli measurements to determine whether fresh water is safe for recreation. Disease-causing bacteria, viruses and protozoans may be present in water that has elevated levels of E. coli. Levels of E. coli can increase during flooding. E. coli is measured in number of colony forming units. The EPA water quality standard for E. coli bacteria is 394 colony forming units per 100 mL.