To: Interested Parties
From: Environmental Services division
RE: august
2000 Water
Quality Monitoring Report
This
is the Sabine River Authority Water Quality Summary for August 2000. Water
quality sampling was performed August 8th through August 10th. Recent
weather in the Basin was hot and very dry with the exception of the Orange
region where 3.02 inches of rain was recorded in the nine days prior to the
sampling event. Daytime high air temperatures during the seven days prior
to the sampling dates were in the upper 90's and low 100's in the Upper and
Lower Basin. Nighttime lows were in the 70's.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake
Tawakoni
For
the August sample run, most of the water quality values seen at the Upper Basin
sites were consistent with water of high quality. Lake Fork and Tawakoni
reservoirs had only slight temperature differences from surface to bottom but
dissolved oxygen gradients were seen at six to eight meters depending on the
location. Percent saturation of oxygen was over 100% at LT23C, LT23D, and
at three river sites (LF20, SR21, and SR19). Dissolved oxygen was less
than 5mg/L near the dams at Lake Fork and Lake Tawakoni. Additional
measurements at Lake Tawakoni indicated oxygen was well over 5mg/L about ¼ mile
from the dam. Warming of deeper water by convection heating from the dam may
have caused hypoxic water from the bottom to circulate to the surface.
Some consideration should be given to move LF2 at Lake Fork and LT23A at
Tawakoni a little farther away from the structure in order to reduce possible
localized effects from the dam. Orthophosphate was slightly elevated at
LT23D. River sites were unusually clear after the period without
rainfall. Only one site, SR15, had elevated fecal coliform. Since
high coliform counts are unusual during dry weather, SRA notified the City of
Longview of a possible wastewater leak. Further sampling and groundwork by SRA
and the City of Longview led to the discovery and repair of a leaking
wastewater pipeline in a secluded area near the city limits of Longview.
Other water quality parameters compared at upstream and downstream sites
indicate no impairments other than slightly elevated ammonia at SR15.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
August WQM sampling results were
indicative of high water quality at most sites. Toledo Bend Reservoir was near
pool level during this sampling event.
Profiles taken at deep-water stations on the reservoir exhibited thermal
stratification and had anoxic conditions at deeper depths. Oxygen levels at Stations TB6N, TB6I, TB6M
and TB6 were below stream standards. Sulfate levels at Stations TB8 and BA4
exceeded stream standards. Stations BA4
and TB6N had higher nitrite/nitrate levels and conductivity readings compared
to other stations sampled during this time.
Station BA4 is sampled from a bayou that receives discharge from a paper
mill. Station TB6N is sampled from a bayou that receives effluent from a
municipal wastewater treatment plant.
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.
All values measured were within stream standards criteria. A definite salt-water wedge was observed at
tidal stations. The greatest salinity
measured occurred at SRT1 with a reading of 22 ppt at 9.7 meters deep.
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
903-878-2420 (sraubfo@yahoo.com)
Ø
Lower and Tidal Sabine Basin
Cynthia Darbonne, Lower Basin Field Office Coordinator
409-746-3284 (darbonne@sra.dst.tx.us)
Ø
If
above are unavailable
Miles Hall, Assistant
Division Manager Environmental Services
409-746-3284 (mhall@sra.dst.tx.us)
Printed Friday, September 29, 2000