To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Report for September 2002. This first report for the Fiscal Year 2003 has a few changes. In the Lower Basin, station BCC1 was added. In the Upper Basin, BS18 was dropped and BS1 upstream was added to provide for the use of a USGS flow gauge station at that site (USGS 08019500 Big Sandy Ck nr Big Sandy, TX). Sample station maps have been updated accordingly.
Water quality sampling was performed September 10th through September 12th. Recent weather in the Basin was hot with daytime high air temperatures in the 90s at Lake Tawakoni and Lake Fork and in the 80s and 90s at Toledo Bend Reservoir and Orange. Lows were mostly in the 70s at night. The Upper Basin received 2.93 – 2.60 inches of rainfall during the 28 days since the previous sample run as recorded at Lake Tawakoni and Lake Fork respectively. Toledo Bend received 2.56 inches during the 28 days preceding the sample run. Orange received 5.59 inches in the 28 days prior to the sample run. Reservoir profiles indicated stratification of the water column with a distinct thermocline in each reservoir.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the September sample run, most of the parameter's values seen at the Upper Basin sites were consistent with water of high quality. The most recent significant rain was 0.29 inches at Lake Tawakoni and 0.47 inches at Lake Fork three days prior to the sample date. Surface water temperatures were between 23.3 and 28.2°C at river and reservoir sites. Two sites, LF2 and LF3, were below stream standards for dissolved oxygen with 4.97 and 4.44 mg/L respectively. Three Upper Basin river sites had over 100% saturation of dissolved oxygen, indicating mild algal bloom conditions. BS1, SR17, SR15, and SR14 exceeded stream standards for E. coli. A leaking wastewater main was discovered and repaired as a result of unusually elevated E. coli values seen at SR15 and SR14. Chlorides at SR11 were slightly elevated above screening levels. There is no stream standard for chlorides, so recommended screening criteria are used as a guide for what should be expected. Surface water temperatures near the dams at Lake Tawakoni and Lake Fork were 27.0 and 27.1C respectively. Bottom temperatures at the same sites were 22.0 and 15.2C respectively. Both reservoirs were thermally stratified.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The September monthly sampling results were indicative of water of high quality at most sites. The last significant rainfall occurred over a week prior to the sampling event. The level of Toledo Bend Reservoir was recorded around 167 feet with no discharge from the spillway gates or the generator at the time of sampling. All lake sites showed some stratification, but only the deepwater stations showed anoxic conditions at the deepest depths. Stations TB6N, TB8, and TB6M had oxygen levels that were below the stream standard. Station BA4 and TB8 had a sulfate result that was above the stream standard. Chloride results were found to be above the stream standard at stations TN6N and TB8, and the E. coli level at TB6N was also above the stream standard.
Tidal Section of the Sabine Basin below Morgan Bluff
Stations sampled in the tidal portion of the Sabine Basin had values that were consistent with water of high quality at most sites. The area received close to two inches of rain in the week prior to the sample event. Similar temperatures were found throughout the water column at all sites, but the oxygen levels were stratified at the deep-water stations, and only the deepest depths at these stations showed anoxic conditions. Surface salinities were found at all but one of the tidal stations with station ICW1 recording 4 ppt, BB1 having 6 ppt and SRT1 with 4 ppt. The highest salinity values were found at the deepest depths at the deep-water stations. Station SRT2 recorded 12 ppt at 9.8 meters and SRT1 had 14 ppt at 9.8 meters. Station BB1 also recorded a dissolved oxygen result that was lower than the stream standard.
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:
Ø Upper Sabine Basin
John Payne, Upper Basin Field Office Coordinator
Ø Lower and Tidal Sabine Basin
Jerry Wiegreffe, Lower Basin Field Office Coordinator
If above are unavailable
Miles Hall, Assistant Division Manager Environmental Services
Printed Monday, November 04, 2002