Lake Braddock Post-lab

Sonia Lee APES pd. 5 Lab Analysis Questions Chemical analysis of water quality 1. Why does cold water hold more oxygen than warm? When the water gets warm less gas dissolve faster. Therefore, the warm water holds fewer amounts of oxygen then cold water. 2. At what time of day would you expect to have more DO? Explain. During the day is when photosynthesis occur the most because of the sunlight they get. The more sunlight the plants get the more photosynthesis the plants make. Photosynthesis is what makes the oxygen. So the more photosynthesis, the more oxygen will be produced. 3. What problems are associated with eutrophication? Eutrophication is caused when run-offs, such as nitrate and phosphate, gets added into the water. The water then gets a sudden algae bloom causing less sunlight to enter the water. This decreases photosynthesis and so many organisms to die because of the decrease in oxygen. 4. In which season would you expect the surface water turbidity levels to be higher, summer or winter? Why? Summer would have a higher level of turbidity.

5. What effect does turbidity have on plant and animal life in aquatic ecosystems?

A high Turbidity is when the water gets cloudy and covered. This makes the waters become warmer and so it reduces the oxygen in the water. Some organisms and animals under water can’t survive in warmer water. The high turbidity also affects the plants, since much sunlight can not get through it decreases the photosynthesis. The decrease of photosynthesis lowers the oxygen more. 6. What is the WQI for Lake Braddock and what rating does this correspond with? The WQI was 60.5 and that falls under the WQI value 51-70 which is an average water quality rating. 7. What are specific possible pollution sources for the lake? What are possible control methods for these sources? Non-point runoff is one way the lakes get polluted and a control method for that is to reduce the use of pesticides and use an exact amount of fertilizers. Fertilizers and pesticides applied near a body of water should be reduced as well. Another possible pollution source is the sewage that consists of many chemicals and toxics that leak into groundwater. One control method is to work with nature to treat sewage by the use of artificial wetlands to treat sewage as a low-tech and low cost alternative to expensive waste treatment plants. When the four R’s (refuse, reduce, recycle, reuse) are not used it causes pollution. A possible control method is by using the four R’s by reducing the amount of fertilizers and pesticides, recycling papers and metals, and reusing the recycled materials. Also, Thermo pollution in waters could be reduced in all power plants. 8-9

Dissolved Oxygen (DO)

pH

Temperature Change

Fecal Coliform BOD Nitrate

Phosphate

Total suspended solids (turbidity)

8. Humans impact on the levels When the humans use more fertilizers then they need to, they impact the DO level because of the excess fertilizers that become run-offs. Humans burning coal, which the smoke has sulfur, get up into the atmosphere. When it starts to rain the sulfuric acid falls into the water which drops the pH levels. The humans can impact the temperature with power plants causing thermo pollution.

9. Adverse affect of unhealthy levels Run-offs like fertilizers that get into the water cause the DO to decrease.

The human excess use of fertilizers and pesticides that goes in the water creates eutrophication. The human excess use of fertilizers and pesticides that goes in the water creates eutrophication.

Run offs causes nitrate to be added into the water causing an algae bloom.

When it rains the rain may be acidic and thus makes the water acidic. Acid rain could result in loss of specific species.

Run offs causes phosphate to be added into the water causing an algae bloom. Erosions cause the water to become cloudy which means it has a high turbidity.