Sabine River Monitoring
The Sabine River Basin is approximately 300 miles long and extends from northeastern Texas to Sabine Lake and on to the Gulf of Mexico. The Sabine River and watershed provide a wide variety of recreational opportunities, such as fishing, boating, hiking, and hunting to countless residents and visitors each year.
Since 1982, Eastman Chemical Company, Texas Operations has sponsored a series of biological and water quality surveys on the Sabine River near Longview, TX, by the Patrick Center for Environmental Research of the Academy of Natural Sciences of Drexel University. The present study was conducted in October of 2010; previous studies were completed in 1982, 1987, 1995, 2000, and 2005.
Additional studies were conducted in August 2013 to address questions that arose as a result of the 2010 survey. These involved the collection and analyses of sediment samples to more clearly define the spatial extent of nickel concentrations throughout the study area; and, a literature review of mercury concentrations in fish tissues taken from similar Gulf Coast river systems.
Map of the 2010-13 Sabine River study area and inset showing the location within the state of Texas.
- Overall, the 2010-13 Sabine River surveys indicate that there was little or no significant impact on the aquatic environment from Eastman facility operations.
- The water quality and the condition of biological communities in the river near Longview, TX, were broadly similar to those in 2005 and 2000 and substantially better than in 1987 or 1982.
- These improvements in river conditions parallel improvements in Eastman waste water treatment since the initial Academy study in 1982.
Senior chemist Paul Kiry compositing a water sample in Zone 4.
- Water quality analyses indicate that:
- Conductivity, total alkalinity, total dissolved solids, sulfate, chloride, and dissolved organic carbon values increased between Zones 2 and 3U, i.e., downstream of the facility outfall.
- All of these parameters decreased slightly below the upper part of Zone 3.
- Calcium hardness increased only slightly from upstream to downstream zones.
- Various forms of nitrogen analyzed showed different spatial patterns among Zones 1-4:
- Nitrite increased downstream of Zone 2.
- Nitrate and ammonia decreased from Zone 1 to Zone 4.
- Soluble reactive phosphorus and total phosphate decreased from Zone 1 to Zone 4.
- Dissolved oxygen concentrations were sufficient for fish and macroinvertebrates.
- The observed differences in chemical concentrations among zones in 2010 could have potentially been affected by the (drought) low flow conditions during the survey.
- In sediment samples, average concentrations of selected organic compounds and several trace metals tended to be higher in 2010 at Zones 2, upper Zone 3, and Zone 4 compared to Zone 1.
- Nickel was detected at a higher concentration in sediment at Zone 3, downstream of the Eastman facility in 2010. However the 2013 sediment study found low levels of nickel at this site, indicating that the higher concentration of nickel recorded during the 2010 study was, most likely, an anomaly.
- Trace metal concentrations in mussels collected in all four zones were low, with variable trends among zones. Concentrations of selected organic compounds tended to be higher in Zones 2-4.
- Mercury was found in fish tissue at concentrations below the US Food and Drug Administration action level, but above the US EPA mercury guideline for fish consumption.
- There was no trend in mercury concentrations in fish tissues among zones.
- Mercury is not used in the Eastman facility.
- Mercury in fish tissues is a widespread condition in east Texas rivers and lakes.
- The 2013 mercury literature review indicated that mercury concentrations in Sabine River fish collected during the 2000-2010 surveys are in the range of concentrations reported in fish collected from other regional water bodies.
Algae and Aquatic Plants
Phycologist Frank Acker collecting algae from a log. (left) Examples of some of the taxa identified include the blue-green alga Anabaena (bottom right) and the diatom Thalassiosira (top right)
- Algae studies on the Sabine River have been based on analyses of algal communities collected from different substrates and habitats within the four study zones.
- Possibly due to low river flows and water velocities, there was a greater amount of sedimentation within each zone than in previous surveys.
- Increased light penetration allowed for larger areas of algal growth directly on the sandy-muddy riverbanks and in the many mudflat areas.
- Large patches of diatoms dominated the algal communities in all zones and growths of filamentous green and blue-green algae were more prevalent in 2010 than in the 1995-2005 studies, especially in the zones below the facility
- There were indications of nutrient enrichment in all sampling zones, with origins from sources upstream from Eastman’s facility.
- This level of enrichment is similar to that observed in the 1995-2005 studies, but much reduced from that seen in the 1982 and 1987 surveys.
Aquatic ecologist Brett Marshall collecting insects from a log during the 2010 study. Aquatic insects, like this dragonfly, are important components of the Sabine River aquatic ecosystem.
- Several analyses suggested that the Sabine River supported healthier aquatic insect communities than observed in any of the previous surveys, which started in 1982.
- The aquatic insect studies indicate limited Eastman impacts on the Sabine River study area.
Dr. Raymond W. Bouchard, Jr. holding two washboard mussels. Freshwater mussels and crayfish are two of the many different kinds of non-insect macroinvertebrates found during the 2010 Sabine River studies.
- The 2010 non-insect macroinvertebrate survey did not reveal any strong impacts from Eastman operations.
- Numbers of non-insect macroinvertebrate species decreased from 2005 to 2010, possibly due to the low river levels during the survey.
- Freshwater mussel diversity remained stable with one new mussel species, the lilliput, recorded for the first time in Academy Sabine River surveys.
- In the most recent surveys (1995-2010), differences in the non-insect macroinvertebrate fauna among zones and surveys have been related to variability in habitats and river flows.
Fisheries biologist Paul Overbeck using a backpack electrofisher to sample the riffle habitat at Zone 3. (left) Many species of fish were recorded during the 2010 study including the Black Buffalo (middle-top) and Longear Sunfish (middle-bottom) Fisheries biologists Paul Overbeck (left) and Dave Keller (right) using a seine to collect smaller fish in shallow water at Zone 2. (right)