Sabine River Authority of Texas
From: Environmental Services division
RE: december 1999 Water Quality Monitoring Report
This is the Sabine River Authority Water Quality Summary for December 1999. Water quality sampling was performed December 14 through December 16. Daytime high air temperatures during the seven days prior to the sampling dates were mostly in the 50ís and 60ís in the Upper Basin and in the 60ís and 70ís in the Lower Basin. Nighttime lows were in the 30ís and 40ís in the Upper Basin and about ten degrees warmer in the Lower Basin. Most of the Sabine River Basin received a significant rain event a few days prior to sampling.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the December sample run, most of the water quality values seen at the Upper Basin sites were consistent with water of high quality. The most recent rainfall was 2 inches two days prior to sampling. Lake Tawakoni recorded 3.73 inches of rain since December 1st (14 days previous) and Lake Fork recorded 3.39 inches during the same period. Water temperature and dissolved oxygen profiles were similar from surface to bottom at Lake Tawakoni and Lake Fork indicating complete mixing, with no thermal stratification. Water quality parameters were within stream standards at all Upper Basin reservoir sites. Most of the Upper Basin river sites exceeded stream standards for fecal coliform but fecal streptococcal bacteria were also elevated at these sites, indicating probable sources are non-human warm-blooded animals. This is not unusual after a recent rainfall runoff event. SR21 had elevated conductivity and chlorides, most likely from natural salt deposits in the Grand Saline watershed upstream.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
Samples taken during the December WQM sampling were indicative of high quality water at most sites. At the time of sampling, Toledo Bend Reservoir was still exhibiting low water level conditions. The surrounding area received some rainfall prior to sampling but not enough to change water levels. Deep-water stations of the reservoir were well mixed, with no thermal stratification. Station TB6N, located below a municipal wastewater treatment plant, had higher conductivity, chloride, TOC, fecal coliform and fecal strep results. Station TB6N also had very low dissolved oxygen concentrations compared to other sites. Station BA4, located below a paper mill, had higher conductivity, chloride, sulfate, TOC, fecal coliform and fecal strep results. Samples taken from Station SR3, located downstream of BA4, exhibited the same black color as the water in Anacoco Bayou. Station BCC1 had elevated fecal coliform levels, which could be attributed to rainfall less than a week previous to sampling event.
Tidal Section of the Sabine Basin below Morgan Bluff
Water samples indicative of high quality were collected from the tidal portion of the Sabine Basin. All surface water values measured were within stream standards criteria. A definite salt-water wedge was detected as far north as the I10 Bridge. Salinity readings ranged from <1.0 ppt at surface to 16 ppt at a depth of 9.8 meters. No tidal action was observed at the time of sampling. Deep-water profiles were well mixed and exhibited no thermal stratification.
This Report and additional data for these monitoring stations are available on our World Wide Web site (www.sra.dst.tx.us). If you have any questions or comments concerning this report, please contact:
Printed Wednesday, July 19, 2000