Kathleen A. Garlandgarland@uhcl.edu

281-283-3249

EIH Envirothon Teacher WorkshopFebruary 18, 2012

What’s a point source?

Industrial or municipal discharge

End-of-pipeThe key concepts for understanding point

source pollution

Channelized flowIt has a distinct sourceYou can identify that sourceYou can control that source

Non-point source pollutionNo 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…

NitrogenPhosphorusPotassium

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?

EutrophicationNutrients feed algaeAlgae bloom, creating large amounts of biomassAlgae die, sinking to the bottom of the water

bodyAlgae decay, using up the oxygen in the lower

layer of the waterBenthic (bottom-dwelling) organisms cannot

surviveFish eat benthics, so they either move away, or

they die, too

Eutrophication leads to HypoxiaHypoxia: the condition of extremely low

levels of oxygen in the waterIn 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 hypoxiaFisheries

Affects fish stocksAffects nursery areas for future fish stocks

Water qualityRecreationalFishing and boatingShellfish

Coral reefs

Recent example: TPWDhttp://www.tpwd.state.tx.us/landwater/

water/environconcerns/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.htmlFor freshwater systemsRequires states to implement plan

Coastal Zone Act Reauthorization Amendments (CZARA) Section 6217http://www.epa.gov/owow_keep/NPS/czara.htmlSpecifically relates to coastal areas—like us!

Why should we care?Galveston Bay is an estuary—a drowned river

basinThe most productive aquatic habitats on the planet

Wetlands and marshes Seabirds, turtles, shellfish, and ocean fish

Extremely vulnerable to pollution from NPSNeeds freshwater inflows to surviveDownstream from two massive urban areas: DFW

and Houston Industrial pollution Urban runoff Agricultural runoff

If those inflows are nutrient loaded, the Bay suffers

Chesapeake BayA 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!