Water Quality

By Siddharth Samal

Indicators of Water Quality

To understand the quality of water, people look for certain properties in water and monitor if that property level is okay or if it is a problem. These properties are called indicators. Such indicators are the pH of water, turbidity of water, temperature, nitrates, dissolved oxygen, and bio-indicators in water. These indicators have are allowed to have a certain level or amount in water.


PH is the concentration hydrogen (H+) ions water has. High pH of a certain substance in water can be harmful to aquatic and human life. An example would be ammonia. Ammonia can be very toxic to aquatic life at high pH. Low pH of a substance in water is usually not a problem but can it be.

Dissolved Oxygen

Dissolved oxygen is very essential for life, especially aquatic life. It is a product of photosynthesis and diffusion. Summer is often a time of oxygen stress for aquatic organisms because water gets warmer in the summer. The warmer water is, the less amount of dissolved oxygen it contains which is necessary for aquatic organisms to breathe and live, but that doesn't mean water should always be really cold. Most aquatic organisms can live in water as cold as 32 degrees Fahrenheit. Sometimes dissolved oxygen gets reduced because of suspended sediment rocks blocking sunlight to plants. When algae die and decay in water, the high bacterial load rapidly consumes dissolved oxygen killing aquatic life.


Turbidity is the clarity of water. Suspended sediments in water increases its turbidity because they collect any harmful objects which makes water more efficient to drink or use for other purposes. Some bacteria decrease the turbidity of water so, certain chemicals are added to water to increase the turbidity of water. As turbidity of water increases, it gets cleaner and is better to use.


Temperature greatly affects water. Most aquatic organisms can live with a temperature range of 32 degrees Fahrenheit to 90 degrees Fahrenheit. Temperature can also affect the amount of dissolved oxygen in water. As said earlier, the warmer water is, the less amount of dissolved oxygen it contains which is necessary for aquatic organisms to breathe and live. Some organisms can't live very long in cold or hot temperatures so water is maintained at a moderate temperature.


Nitrate is a plant nutrient that is converted from ammonia by bacteria. There is a restriction level for the amount nitrate in water. Too much nitrate is bad for our body. Excess nitrate also causes algal blooms that reduce water quality. Little nitrate is necessary for our body and other organisms. Nitrate is soluble and moves easily from surface to groundwater.


Bio-indicators are species and a sort of water indicator that can be used monitor the health of an environment or ecosystem as well as water quality. There are many biological species or group of species whose function, population, or status can reveal what degree of environmental integrity is present. This means that these properties or characteristics of water can let us know the health of water. There is not really a bad effect of bio-indicators on water. They don't harm water much.
This is the website used to get some information. Click

Most of my information was from my notes.