Safe Drinking Water Act Case Studies: AP Environmental Science Examples

💧 Quick Study Guide: Safe Drinking Water Act (SDWA)

• 📜 Purpose & History: The Safe Drinking Water Act (SDWA) was passed by the U.S. Congress in 1974 to protect public health by regulating the nation's public drinking water supply. It was significantly amended in 1986 and 1996 to strengthen its provisions.
• 🏛️ EPA's Role: The Environmental Protection Agency (EPA) is responsible for setting national standards for drinking water quality. These standards include Maximum Contaminant Levels (MCLs) for various pollutants.
• 🔬 Regulated Contaminants: The SDWA mandates the regulation of numerous contaminants across several categories, including:
  • 🦠 Microbial Contaminants (e.g., *Cryptosporidium*, *Giardia*, viruses)
  • 🧪 Disinfectants and Disinfection Byproducts (e.g., chlorine, trihalomethanes)
  • 🪨 Inorganic Chemicals (e.g., lead, arsenic, nitrates)
  • 🌿 Organic Chemicals (e.g., pesticides, industrial solvents)
  • ☢️ Radionuclides (e.g., radon, uranium)
• ⚙️ Public Water Systems (PWS): The SDWA applies to all public water systems that provide water to at least 25 people or have 15 service connections for at least 60 days a year. These systems must treat water to meet MCLs, monitor for contaminants, and notify the public of any violations.
• 📣 Key Amendments (1996): The 1996 amendments emphasized source water protection, enhanced public right-to-know provisions (e.g., Consumer Confidence Reports), and risk-based standard setting.
• 📉 Compliance & Enforcement: States are primarily responsible for implementing and enforcing SDWA, though the EPA can take direct action if states fail to do so.
• 🔎 Relevant Case Studies & APES Examples:
  • 🏙️ Flint Water Crisis (Michigan): A stark example of regulatory failure and environmental injustice. The city switched its water source without adequate corrosion control, leading to lead leaching from pipes into the drinking water. This highlighted infrastructure issues and the vulnerability of public health.
  • 🧪 Hinkley, California (Chromium-6): Famous for the legal case against Pacific Gas & Electric (PG&E) due to groundwater contamination by hexavalent chromium, a known carcinogen. This case underscored the challenges of industrial pollution and the need for stringent contaminant monitoring.
  • 🚜 Agricultural Runoff: Widespread issue where nitrates, pesticides, and other pollutants from farms enter surface and groundwater, posing challenges for drinking water treatment, especially in agricultural regions.
  • 🛢️ Fracking & Groundwater: Concerns about hydraulic fracturing (fracking) potentially contaminating groundwater sources with chemicals and methane, impacting local drinking water supplies.

🧠 Practice Quiz

1. Which of the following is the primary federal agency responsible for setting national standards for drinking water quality under the Safe Drinking Water Act (SDWA)?
   A. U.S. Department of Agriculture (USDA)
   B. Environmental Protection Agency (EPA)
   C. Food and Drug Administration (FDA)
   D. Centers for Disease Control and Prevention (CDC)
2. The Safe Drinking Water Act (SDWA) primarily focuses on protecting which of the following?
   A. Agricultural irrigation systems
   B. Private well water on individual properties
   C. Public drinking water supplies
   D. Bottled water manufacturers
3. The Flint Water Crisis is a significant case study related to the SDWA primarily due to contamination by which substance?
   A. Arsenic
   B. Chromium-6
   C. Lead
   D. Mercury
4. Maximum Contaminant Levels (MCLs) are standards set by the EPA under the SDWA to:
   A. Regulate the amount of water used by industries.
   B. Limit the concentration of pollutants allowed in public drinking water.
   C. Determine the maximum amount of rainfall allowed in a watershed.
   D. Set the highest acceptable level of water pressure in municipal pipes.
5. The 1996 amendments to the SDWA placed a greater emphasis on which of the following?
   A. Reducing the number of regulated contaminants.
   B. Increasing federal funding for dam construction.
   C. Source water protection and public right-to-know.
   D. Shifting all enforcement responsibilities to local governments.
6. The case of Hinkley, California, highlighted groundwater contamination by which specific chemical?
   A. Nitrates from agricultural runoff
   B. Hexavalent chromium (Chromium-6)
   C. *Giardia* cysts from sewage
   D. PCBs from industrial waste
7. Which of these contaminants is NOT typically regulated under the Safe Drinking Water Act?
   A. *Cryptosporidium*
   B. Arsenic
   C. Chlorine
   D. Ocean plastic debris