Water quality in the galveston bay system
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Transcript of Water quality in the galveston bay system
Water Quality in the Galveston Bay System
Teresa LongDecember 6, 2012
Galveston Bay System• Semi-enclosed body of water where freshwater from rivers,
bayous and tributaries mix with salt water from the Gulf of Mexico
• Six segments with a combined surface area of 519.1 square miles
• Valuable natural and economic resource• Subtropical ecosystem which provides a valuable nursery for a
diverse array of plant and animal species• Sustains water-based industries such as recreational and
commercial fishing, travel, and ecotourism • Port of Houston is the second-largest port in the United States
• Transportation link for petrochemical industries2
Oyster Waters
• Galveston Bay oyster fisheries produce more oysters than any single water body in the United States• Prior to Hurricane Ike, the annual Galveston Bay oyster harvest
totaled between 3 and 4 million pounds valued at nearly 10 million dollars
• Approximately half of Galveston Bay is under some form of oyster harvesting restriction • Nine segments are on the Texas Water Quality Inventory
and 303(d) List for fecal coliform bacteria impairments(TCEQ, 2012)
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Oyster Waters• Oysters are filter feeders are capable of filtering a volume of
water per hour that is approximately 1500 times the volume of their body (Lester, 2002)
• A single oyster filters 50 gallons of water in a single day • Due to the large amount of water filtered, any bacteria
present in water concentrates in oysters • Human consumption of oysters harvested in waters with high
levels of bacteria presents a serious public health concern• Impairment of oyster waters is most likely mainly due to
human activities such as discharging boat sewage into the water
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Water Quality Intern at Galveston Bay Foundation6/2012-12-2012
Galveston Bay Foundation is a nonprofit organization that works to preserve, protect and
enhance Galveston Bay• Advocacy Team• Seeks solutions to conflicts among diverse users of the
bay in an effort to protect long-term interests• Reducing bacteria levels in the bay and improving water
quality in general is of great importance in ensuring public health and local economy
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Water Quality Intern at Galveston Bay Foundation6/2012-12-2012
• Water Quality Projects• Texas Stream Team Certified Trainer• Training Volunteer Water Monitors• Bacteria sampling & analysis• Data management
• Various education campaigns and public outreach events• Research / Data Collection supporting efforts to have the
Galveston Bay system declared a No Discharge Zone• Developed tools to collect and disseminate information• Web-based applications • Interactive maps 6
Water Monitoring• Data points generated via
chemical analyses, physical testing, and general observations produce a unique portrait of water quality parameters for that particular site and moment in time
• Over time, trend analysis provides many clues and can facilitate early identification of potential water quality issues caused by nonpoint source pollution 7
Point Sources vs. Nonpoint Sources
• Point sources are single, identifiable pollution sources subject to permit requirements and regulated by the Federal Clean Water Act and Texas Law• Effectively regulated and monitored
• Nonpoint sources originate from many sources which can be difficult to identify • Largely unregulated and not subject to permit requirements • Analyzing data for trends and correlating it to human
contributions can be an effective strategy to define nonpoint source pollution
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Reducing Bacteria Levels
• Galveston Bay Foundation has been tasked with developing an Implementation Plan aimed at reducing bacteria levels in Galveston Bay
• Boat sewage discharged into the Galveston Bay system is a nonpoint source pollutant• Elevates bacteria levels• Lowers dissolved oxygen content
• Untreated discharge from just one weekend boater puts the same amount of bacterial pollution into the water as the treated sewage of 10,000 people
• The ultimate goal is to secure a No Discharge Zone declaration from the U.S. Environmental Protection Agency for the Galveston Bay system
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Texas Stream Team
• Statewide network consisting of hundreds of trained volunteers who regularly collect and submit water quality data
• Volunteers are provided a kit and trained to conduct testing and record data in a manner that produces clear, consistent results
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Volunteer Water Monitor Training
• Phase I – Classroom training that includes orientation, demonstration, and practice
• Phase II – Group field training, and individual testing, focuses on recording field observations
• Phase III – Site visit that includes site assessment by a certified trainer, individual training on chemical and physical testing methods, evaluation of proficiency, and volunteer certification
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Chemical and Physical Testing
• Dissolved Oxygen• Salinity• pH• Temperature (Air and Water)• Water Transparency• Depth• Field Observations
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Dissolved Oxygen Concentration
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• Measure of amount of oxygen freely available in water
• Measured in milligrams per liter (mg/L)• <2 mg/L: Fatal to most
species• <3 mg/L: Stressful to
most species• >5 mg/L: Sufficient for
most species
Dissolved Oxygen Concentration• Volunteer monitors
come from all walks of life and have various levels of scientific knowledge and experience
• Successful Phase III training and certification depends on the ability of the trainer to teach techniques• Reading meniscus 14
Salinity
• Measures the concentration of dissolved salts in water• Dissolved salt content
affects distribution of plant and animal life• As salinity increases,
dissolved oxygen concentration decreases 15
pH
• Most suitable range for aquatic life = 6.5-9• Significant changes in
pH, either sudden and dramatic or a steady increase over time, may be an indicator of problems
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Temperature• Air and water
temperature are measured in degrees Celsius• Aquatic species require
specific temperatures ranges in order to survive• Direct correlation to other
parameters being measured, such as dissolved oxygen concentration
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Water Clarity / Total Depth
• Transparency is a measure of turbidity or clarity• Total depth of the
exact sample point is recorded and used in trend analysis• Measured in meters
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Field Observations• Volunteer monitors record
observations on a regular basis• first-hand knowledge of water
quality conditions that may not be immediately apparent from chemical analysis
• Algae cover• Water surface conditions• Current weather conditions• Tide Stage, Rainfall• Water clarity, color and odor• General observations that may
affect the sample collected, such as nearby boat traffic or unusual foam, odors, etc. 19
Source: HGAC
Bacteria Analysis
• Enterococcus is an indicator bacterium normally found in the intestines of humans• Better indicator of
human sewage in brackish waters than fecal coliform• Analyzed via IDEXX
Enterolert method 20
Source: CDC
Conclusion• Galveston Bay Foundation has a team of 29 Certified Water
Monitors• Increased from 9 monitors in June 2012• 6 monitors to be trained in the next 2 weeks
• Bacteria Lab is operational• Solid foundation in place for collecting, analyzing, and
presenting data to the U.S. Environmental Protection Agency requesting Galveston Bay to be declared a No Discharge Zone
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Galveston Bay FoundationCertified Volunteer Water Monitoring Team
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There is No Substitute
23Source: witchitafalls.gov
References
Lester, J., Gonzolez, L., Sage, T., & Gallaway, A. (2002). The state of the bay: A characterization of the galveston bay ecosystem. (2nd ed.). Webster, TX: Galveston Bay Estuatry Program.
Texas Commission on Environmental Quality, Total Maximum Daily Load Section. (2009). Six total maximum daily loads for bacteria in waters of the upper gulf coast segments 2421, 2422, 2423, 2424, 2432, and 2439. Austin, TX.
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