2.  What determines the safety of a water source and how potable it is?  Potable – safe for humans to drink  Biological, physical, and chemical variables

3.  Bacteria, viruses, and parasites can contaminate water  Come from sewage and animal waste

4.  Temperature  Lower temp = water can hold more O 2  Higher temp = plants grow faster and produce O 2  Water Movement  Faster water flow dilutes pollution faster  short video clip

5.  Turbidity  How cloudy water is  High turbidity can suffocate fish eggs and make it hard for fish to breathe

6.  Dissolved oxygen  microscopic bubbles of gaseous oxygen (O2) that are dissolved in water  Comes from - photosynthesis and the atmosphere

8.  pH  Measure of the acidity of a liquid  Indicated using a 0 -14 scale (0=acid) (14 = base)  Vinegar = 3 seawater = 8.3

9.  Effects of High pH  Water with high pH typically contains large amounts of dissolved minerals, particularly calcium and magnesium. These represent the principal components of "hard" water. The minerals do not pose a direct health threat, but they cause other problems, such as scale buildup inside water pipes, soap scum, and decreased effectiveness of soaps and detergents.  Effects of Low pH  Acid water with a pH less than 6.5 poses no direct health threat. However, acidic water tends to dissolve metals, including lead, copper, zinc, iron, manganese and other metals commonly found in household water-supply pipes. This process also results in corrosion of the pipes.

10.  Salinity  refers to the amount of salt dissolved in water o Takes up space oxygen can’t use  “a salt is a crime in which one person attacks and means to harm another person...”

11.  Salinity  Temperature  Dissolved Oxygen  pH  Light  Nutrients  Substrate (base layer)  Circulation (water movement)

12.  Animals that tell us how healthy an ecosystem is  Provide an early warning of environmental damage  Can’t be too tolerate

13.  Are often insects  3 main types  Pollution Intolerant  Pollution Semitolerant  Pollution Tolerant

14.  I am a dolphin living off the coast of Georgia. I live near a delicious smelling breakfast making factory. One day, the plant workers were throwing a party to celebrate St. Patrick’s day when they left the machines unattended and the large coffee making section of the plant exploded. 250,000 gallons of scalding hot coffee were released into the ocean near my home. This decreased the pH level of the ocean because coffee is acidic. It also increased the water temperature, so the DO levels went down and my family was forced to evacuate from our home. We found out about what happened because my brother likes to play close to the drainage pipe from the factory. The coffee was such a major point pollution source that our home was uninhabitable for weeks and we had to go stay with some cousins who live in Florida. When we got to their house, my mom got sick because she was not used to the bacteria that they have in Florida in the river where my cousins live. Fortunately She did not stay sick for long because the river had a fast current, and would carry the bacteria away as soon as it would grow.

15.  Pre 1970  Worried about microorganisms in water causing disease  After 1970  Worried about pesticides, industrial sludge, and chemicals

16.  Runoff can carry chemicals or oil  This can percolate into groundwater  Humans dump sewage waste into rivers  This is why U. S. standards were first introduced in 1914

17.  1940 – laws were passed to make sure municipal water was safe  1972 – Clean Water Act  For…  1974 – Safe Drinking Act – ensures quality of drinking water

18.  Studies of perchlorate (a chemical found in explosives) show that it can disrupt the thyroid, a master gland essential for growth and development. That means that fetuses are at the highest risk for perchlorate damage  Industries as well as people need water. It  takes, on average, 39,090 gallons of water to  manufacture a new car and its four tires.