Types of Pollution Sources (College Board AP® Environmental Science) : Study Guide

Point source pollution

• Point-source pollution is easy to identify as there is a clear source of the pollutant, such as smoke from a smokestack of a factory, untreated sewage coming out of a pipe into a river and vehicle exhaust coming out of a car's tailpipe

• A key feature of point source pollution is the plume, which is the area where the pollution is strongest

• This makes it easy to control since the type of pollutant and its location are known

• Easy to fine the polluter if they do not comply with the terms of their permit

• Easy to monitor if the pollutant is above or below allowed limits

Nonpoint source pollution

• Nonpoint-source pollution happens when pollutants come from diffused sources that are hard to pinpoint or from many sources spread out over a large area, such as urban runoff or pesticide spraying

• Nonpoint-source pollution that flows with water or enters water is called 'runoff'

• Car exhausts are called nonpoint-source pollution because the emissions looks like they comes from a wide area, not just one specific car

• Nonpoint-source pollution is hard to monitor and requires many monitoring stations

• It is difficult to find and fine offenders

Policy and regulation of water pollution in the US

• The Clean Water Act (CWA) is a US law designed to protect water quality by controlling pollution in navigable waters and setting water quality standards

• The primary goal of the CWA is to restore and maintain the chemical, physical, and biological integrity of the nation's waters

• The CWA establishes a permit system (National Pollutant Discharge Elimination System or NPDES) to control point source pollution, such as discharges from factories and sewage treatment plants

• It sets water quality standards for specific pollutants and designates water bodies for specific uses (e.g. drinking water, recreation, fishing)

• The primary focus is on point source pollution, but it also addresses non-point sources like agricultural runoff and stormwater through recommending strategies such as riparian buffer zones

• The CWA also plays a role in protecting wetlands, which are important for water quality and flood control

Safe Drinking Water Act (SDWA)

• This is a US federal law that ensures safe drinking water for everyone. It requires the Environmental Protection Agency (EPA) to set quality standards and oversee their enforcement by states and water suppliers

  • The EPA is responsible for setting national drinking water standards, known as Maximum Contaminant Levels (MCLs), and overseeing their enforcement by states and localities

• The SDWA applies to all public water systems in the United States, which are defined as systems that serve at least 25 people or 15 connections

• The SDWA does not cover private wells or bottled water, which are regulated by the Food and Drug Administration (FDA)