To: Interested Parties
From: Environmental Services division
This is the Sabine River Authority Water Quality Summary for June 2002. Water quality sampling was performed June 11th through June 13th. Recent weather in the Basin was hot with air temperatures in the 80s and 90s during the daytime and lows in the 60s and 70s at night. The Upper Basin received 2.48 – 1.47 inches of rainfall during the 28 days since the previous sample run as recorded at Lake Tawakoni and Lake Fork respectively. Toledo Bend and Orange received 1.41 and 2.31 inches respectively during the 28 days preceding the sample run. Reservoir profiles indicated stratification of the water column with a distinct thermocline in each reservoir. The thermocline was located about 8-9 m deep near the dams at Lake Tawakoni and Lake Fork, 6 m deep near the dam at Toledo Bend Reservoir, and 6 m deep at shallower lake sites upstream of the dams.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake Tawakoni
For the June sample run, most of the parameter's values seen at the Upper Basin sites were consistent with water of high quality. The most recent rain was 0.33 inches at Lake Tawakoni and 0.05inch at Lake Fork one day prior to the first sample date. Surface water temperatures were between 24.5 and 28.2 C. E. coli exceeded the single-grab stream standard limit at SR22. This site also fell below stream standards for dissolved oxygen with 4.07 mg/L and had elevated turbidity. Orthophosphate exceeded screening guidelines at LT23D. State stream standards for orthophosphate do not exist so screening guidelines are used to predict normal conditions. Surface temperatures near the dams at Lake Tawakoni and Lake Fork respectively were about four and eleven degrees warmer than bottom temperatures.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
The June monthly sampling results were indicative of water of high quality at most sites. The last significant rainfall occurred over one week prior to the sampling event. The level of Toledo Bend Reservoir was recorded at 171.8 feet with no discharge from the spillway gates at the time of sampling. The generator was also not operating at the time of sampling. All lake sites were thermally stratified with some of the deep-water stations showing anoxic conditions at the deepest depths. Stations TB6N and TB6M had oxygen levels that were below the stream standard, and station BA4 had a sulfate result that was above the stream standard. The City of Logansport had a wastewater bypass the day before sampling, which resulted in high bacterial counts at station TB8. These bacterial counts caused station TB8 to exceed the stream standard for E.coli. The problem has since been corrected.
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 had only a slight amount of rain in the week prior to sampling. All sites were stratified with respect to dissolved oxygen, but all sites were well mixed with respect to temperature. Surface salinities were found at three of the four tidal stations. Station ICW1 recorded a value of 2.2 ppt, BB1 had a value of 4.9 ppt, and SRT1 had a value of 3.4 ppt at the surface. The highest salinity value of 8 ppt was recorded at station SRT1 at a depth of 10 meters. All values recorded in this section of the Basin were within their 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, August 12, 2002