To: Interested Parties
From: Environmental Services division
RE: july 2000 Water Quality
Monitoring Report
This
is the Sabine River Authority Water Quality Summary for July 2000. Water
quality sampling was performed July 18 through July20. Daytime high air temperatures during the
seven days prior to the sampling dates was in the upper 90’s and low 100’s
in the Upper and Lower Basin. Nighttime lows were in the 70’s. There was no significant rainfall in the 14
days prior to the sample run.
Upper Sabine Basin Above Toledo Bend Including Lake Fork and Lake
Tawakoni
For
the July sample run, most of the water quality values seen at the Upper Basin
sites were consistent with water of high quality. Hot, dry conditions and warming of surface waters were the
primary causes for some elevated data points for this month. Lake Fork and Tawakoni Reservoirs were
thermally stratified at around five meters. Percent saturation of oxygen was
over 100% at most reservoir sites and at four river sites (SR21, SR19, SR11,
and SR10). Chlorophyll a was
high at most of the reservoir sites, with a strong correlation between high algal growth and super saturation of the
water with oxygen. Water temperature
was in the low 30’s (degrees C) near the surface at most sites. SR19 slightly exceeded stream standards for
temperature. Orthophosphate was
elevated at LT23D and pH was slightly under stream standards at BS18.
Lower Sabine Basin Including Toledo Bend to Morgan Bluff
July
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
with near-anoxic conditions near the bottom. Oxygen levels at stations TB6N, TB6I, TB6M, and TB6 were below
stream standards. pH levels at stations TB6J and TB6K were slightly above
stream standard limits. Station BA4 had higher nitrite/nitrate levels and conductivity
readings compared to other stations.
This station is sampled from a bayou that receives discharge from a
paper mill.
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. Profiles were
well-mixed with no discernable salt-water wedge at most sites. The greatest
salinity measured occurred at SRT1 with a reading of 16 ppt at 9.6 meters
depth.
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 Monday, September 18, 2000