Turbidity in Water: AP Environmental Science - Causes, Effects, and Testing

📚 Quick Study Guide

• 💧 Definition: Turbidity is the measure of relative clarity of a liquid. It's how much suspended material is in the water.
• 🌱 Causes: Erosion, runoff, urban runoff, wastewater, algae growth, and bottom-feeding fish disturbing sediments.
• 🐡 Effects: Decreased light penetration (affects photosynthesis), increased water temperature (darker water absorbs more heat), and clogged fish gills. Can also carry pollutants.
• 🔬 Measurement: Turbidity is measured in Nephelometric Turbidity Units (NTU) using a turbidimeter.
• 🛡️ Safe Drinking Water Act (SDWA): Sets turbidity standards for drinking water.
• ☀️ Photosynthesis Impact: Higher turbidity reduces sunlight available for aquatic plants, leading to decreased oxygen production.
• 🌡️ Temperature Connection: Increased turbidity raises water temperature, reducing dissolved oxygen levels and harming aquatic life.

Practice Quiz

1. Which of the following is the BEST definition of turbidity?
   1. The temperature of the water.
   2. The amount of dissolved oxygen in the water.
   3. The measure of relative clarity of a liquid.
   4. The pH level of the water.
2. Which of the following is NOT a common cause of increased turbidity in water?
   1. Erosion.
   2. Algae growth.
   3. Acid rain.
   4. Wastewater.
3. What is the unit of measurement for turbidity?
   1. ppm (parts per million).
   2. mg/L (milligrams per liter).
   3. NTU (Nephelometric Turbidity Units).
   4. pH units.
4. How does increased turbidity affect the temperature of water?
   1. It decreases the water temperature.
   2. It has no effect on the water temperature.
   3. It increases the water temperature.
   4. It stabilizes the water temperature.
5. Which of the following is a consequence of reduced light penetration due to high turbidity?
   1. Increased photosynthesis.
   2. Decreased photosynthesis.
   3. Increased dissolved oxygen levels.
   4. Decreased water temperature.
6. What U.S. legislation sets standards for turbidity in drinking water?
   1. Clean Water Act (CWA).
   2. Endangered Species Act (ESA).
   3. Safe Drinking Water Act (SDWA).
   4. National Environmental Policy Act (NEPA).
7. How does increased water temperature (due to turbidity) impact aquatic life?
   1. Increases dissolved oxygen levels, benefiting aquatic life.
   2. Reduces dissolved oxygen levels, harming aquatic life.
   3. Has no impact on aquatic life.
   4. Stabilizes the pH levels of the water.