Non-point Source Pollution Kathleen A. Garland email@example.com 281-283-3249 EIH Envirothon Teacher Workshop February 18, 2012
End-of-pipe • The key concepts for understanding point source pollution • Channelized flow • It has a distinct source • You can identify that source • You can control that source
Non-point source pollution • No specific source location Acid mine drainage
Characteristics of Non-point source • Sheet flow • No identified point where all discharge takes place • Source generally cannot be directly controlled
What’s in the water? • Debris
What are nutrients? • Things that make plants grow… • Nitrogen • Phosphorus • Potassium • Algae is a plant (sort of, a Protist, actually, but close to a plant…it photosythesizes) • Nutrients make algae grow—or overgrow!
Eutrophication • Nutrients feed algae • Algae bloom, creating large amounts of biomass • Algae die, sinking to the bottom of the water body • Algae decay, using up the oxygen in the lower layer of the water • Benthic (bottom-dwelling) organisms cannot survive • Fish eat benthics, so they either move away, or they die, too
Eutrophication leads to Hypoxia • Hypoxia: the condition of extremely low levels of oxygen in the water • In the Gulf of Mexico, we call the hypoxic zone— The Dead Zone
Impacts of hypoxia • Fisheries • Affects fish stocks • Affects nursery areas for future fish stocks • Water quality • Recreational • Fishing and boating • Shellfish • Coral reefs
Recent example: TPWD • http://www.tpwd.state.tx.us/landwater/water/environconcerns/hab/redtide/status.phtml
Who regulates non-point source pollution? • EPA: Section 319 of the Clean Water Act • http://www.epa.gov/owow_keep/NPS/cwact.html • For freshwater systems • Requires states to implement plan • Coastal Zone Act Reauthorization Amendments (CZARA) Section 6217 • http://www.epa.gov/owow_keep/NPS/czara.html • Specifically relates to coastal areas—like us!
Why should we care? • Galveston Bay is an estuary—a drowned river basin • The most productive aquatic habitats on the planet • Wetlands and marshes • Seabirds, turtles, shellfish, and ocean fish • Extremely vulnerable to pollution from NPS • Needs freshwater inflows to survive • Downstream from two massive urban areas: DFW and Houston • Industrial pollution • Urban runoff • Agricultural runoff • If those inflows are nutrient loaded, the Bay suffers
Chesapeake Bay • A very badly damaged estuary
We don’t want to get that way! • What can we do to reduce NPS? • Stay tuned! Dr. John Jacob, of Texas Coastal Watersheds will be speaking at 1:30 on exactly this topic!