14.3 Water: Pollution Answer Key

Why is nonpoint source pollution harder to control than point source? A1: Because it comes from many diffuse locations (e.g., entire farm fields, city streets), cannot be traced to a single pipe, and varies with rainfall, land use, and seasons. Requires voluntary best management practices rather than simple end-of-pipe regulations.

Excessive soil erosion blocks sunlight and chokes aquatic habitats. 14.3 water pollution answer key

A: It begins with nutrient runoff (nitrates/phosphates) entering water. This triggers an algal bloom. When the algae die, bacteria decompose them, consuming all the dissolved oxygen in the process, which kills fish and other organisms. Why is nonpoint source pollution harder to control

Most curricula break water pollution into two main types based on source: Excessive soil erosion blocks sunlight and chokes aquatic

| | Source | Example | Difficulty to Control | | :--- | :--- | :--- | :--- | | Point Source | Single, identifiable pipe or ditch | Factory discharge pipe, sewage treatment plant outlet | Easier (regulate at one point) | | Nonpoint Source | Diffuse, widespread area | Agricultural runoff (fertilizers, pesticides), urban stormwater, construction sites | Harder (requires landscape-level management) |

Examples: A factory drainpipe, an oil tanker spill, or a specific sewage treatment plant.

Note: Treated effluent can be safe for release into rivers or reuse (irrigation, industrial cooling).