Kathleen A. Garland
garland@uhcl.edu
281-283-3249
EIH Envirothon Teacher Workshop
February 18, 2012
What’s a point source?
Industrial or municipal discharge
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
A map of eastern streams
impacted by coal mine drainage
Agricultural runoff
During storms
Runoff from livestock
Concentrated animal feeding
operations
Urban stormwater runoff
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
Sediment in stormwater
Chemicals of concern: Metals
COC’s: oils and greases
Thermal pollution
Nutrients
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!
Not all algal blooms are green…
Why is too much algae a bad thing?
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
How does the Dead Zone Form?
Hypoxic zone in the GOM
Source area for GOM Hypoxic Zone
Global hypoxic zones
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/environ
concerns/hab/redtide/status.phtml
Coral reefs in the northern GOM
Corals in FGBNMS
Invasive species
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!