1. Monitoring Water Quality

2. Water quality is determined by its use. Governments set the guidelines for water quality based on the following 5 categories: 1. Human drinking water (potable) 2. Recreation (swimming etc.) 3. Livestock drinking water 4. Irrigation 5. Protection of Aquatic Life

3. Biological Indicators The number and type of organisms found in water can indicate the health of an aquatic ecosystem Microbiological Indicators Presence of bacteria / protozoans in large numbers may cause illness / death in people who use the water

4. Aquatic Invertebrates The type and number of invertebrates indicates the level of pollution in water A pond with few insects and many worms has little oxygen Below pH 5 = no fish Invertebrates are animals without backbones

5. The diversity of all organisms decreases as acidity increases and dissolved oxygen decreases.

6. Chemical Indicators The concentration of organic and inorganic compounds Has an impact on the water quality Indicators of Water Quality - dissolved Oxygen - acidity - plant nutrients such as nitrogen and phosphorus - pesticides - heavy metals - salts such as sodium chloride and magnesium sulfate

7. Measuring Chemicals in the Environment Parts Per Million Measuring the concentration of chemicals in the environment  (ppm) or milligrams per litre (mg/L)  One part per million means that one unit of an element or chemical can be found in one million units of solution

8. Monitoring Water Quality Parts per million One drop of food coloring in a half-full bathtub 32 seconds in a year! Parts per billion One drop of food coloring in a swimming pool One hamburger in a chain of hamburgers circling the Earth 2.5 times (on their side!) Parts per trillion One second in _________ years One 20cm jump on a trip to the sun 100,000