Ontario Operator-in-Training (OIT) Practice Exam

What does the term 'turbidity' indicate in water quality testing?

1. The presence of color

2. The presence of suspended particles

3. The hardness of the water

4. The temperature of the water

The correct answer is: The presence of suspended particles

Turbidity is an important indicator of water quality that specifically refers to the presence of suspended particles in water. These particles can include sediments, organic material, bacteria, and other pollutants, which can affect the clarity of the water. High turbidity levels can have adverse effects on aquatic life as they can block sunlight, disrupting photosynthesis in plants, and can also indicate higher levels of contamination, making water unsafe for consumption or recreation. In contrast, the other options address different water quality characteristics. The presence of color is indicated by various impurities but does not relate to water clarity like turbidity does. The hardness of water refers to the concentration of calcium and magnesium ions and is distinct from turbidity. Likewise, temperature affects the physical properties of water, such as solubility and chemical reactions, but does not provide information about the presence of suspended particles.