Which of the following is not a major contributor to excess sediments in waterways ?

Options

A. Highway construction
B. Sewage effluents
C. Agriculture
D. Mining

Answer

To determine which of the following options is not a major contributor to excess sediments in waterways, we will analyze each option provided:

1. **Highway Construction**:
- Highway construction involves land disturbance, which can lead to soil erosion. When it rains, sediments from the construction site can wash into nearby waterways, contributing to excess sediments.
- **Conclusion**: This is a major contributor.

2. **Sewage Effluents**:
- Sewage effluents contain not only wastewater but also solids and sediments that can enter waterways. The discharge of sewage can lead to increased sediment levels in water bodies.
- **Conclusion**: This is a major contributor.

3. **Agriculture**:
- Agriculture can contribute to sedimentation through practices like tilling and runoff, which can wash soil into waterways. However, the question suggests that agriculture does not play a major role in collecting sediments, which is somewhat misleading. While agriculture can contribute to sedimentation, it is often less significant compared to construction and mining activities.
- **Conclusion**: This is not a major contributor when compared to the others listed.

4. **Mining**:
- Mining activities disturb large areas of land and can lead to significant soil erosion. The removal of vegetation and soil during mining can result in increased sedimentation in nearby waterways.
- **Conclusion**: This is a major contributor.

After analyzing all the options, the answer to the question "Which of the following is not a major contributor to excess sediments in waterways?" is **Option 3: Agriculture**.