The temperature test gives one insight into the many physical, biological, and chemical characteristics of the river. Temperature affects the amount of oxygen that can be dissolved into the water, the metabolic rates of the aquatic organisms, the sensitivity of the organisms to toxic wastes, parasites, and diseases. It even affects the rate of photosynthesis in plants. The total phosphorus test measures the total amount of organic and inorganic phosphorus in the water. Organic phosphorus comes from dead plant and animal material.
Inorganic phosphorus comes from industrial waste and sewage.
Too much phosphorus in the water may cause cultural eutrophication, the rapid aging of a river. The nitrates test measures the amount of nitrogen, an essential plant nutrient, in the water. A plentiful supply of nitrogen in the water is good, but too much nitrogen may cause algal blooms. The turbidity test measures the amount of suspended solids in the water that may cause light going through the water to be clouded. The total solids test measures the amount of residue in the water.