Section 319
NONPOINT SOURCE PROGRAM SOGGESS STORY
Oil Field Cleanup Reduces Chloride in the West Fork Trinity River
Waterbodies Improved
The Texas Commission on Environmental Quality (TCEQ)
placed the West Fork Trinity River above Bridgeport
Reservoir (segment 0812, which includes two assessment units [AUs]) on the state's 1998
Clean Water Act (CWA) section 303(d) list of impaired waters for failure to meet surface water
quality standards for chloride. Project partners addressed total dissolved solids (TDS) and
chloride contamination from oilfield activities in the Trinity River drainage basin by sealing
abandoned, unplugged, noncompliant oil and gas wells; resealing improperly plugged wells;
and implementing other best management practices (BMPs). Following restoration, TCEQ
determined that segment 0812 met the state's standard for chloride and removed the segment
from Texas' 2012 CWA section 303(d) list.
Problem
The West Fork Trinity River (segment 0812) is an
intermittent stream in the headwaters region of
the Trinity River Basin, slightly northwest of the
Dallas-Fort Worth Metroplex. It begins in Archer
County and flows 85 miles before emptying into
Bridgeport Reservoir, an important water source
for the Tarrant Regional Water District (Figure 1). To
evaluate the segment's water quality, TCEQ divided
the segment into two distinct AUs. The 20-mile
lower segment is AU 0812 _ 01; the 65-mile upper
segment is AU 0812 _ 02. The watershed is entirely
within the North Central Prairie ecoregion, and the
predominant land use in this part of the watershed
is rangeland.
Fourteen water quality grab samples were col-
lected at station 10972 between June 1, 1992,
and May 31, 1997; the mean concentration was
calculated to be 127 milligrams (mg) per liter (L).
This value exceeded the site-specific chloride
standard for segment 0812, which requires that
the mean chloride concentrations remain below
100 mg/L for the assessment period. On the
basis of these data, the state added an 85-mile-
long segment of West Fork Trinity River above
Bridgeport Reservoir (segment 0812, comprising
AUs 0812 _ 01 and 0812 _ 02) to its list of impaired
waters in 1998. The Trinity River drainage basin
has had a history of excessive chloride loadings
from nonpoint sources, both natural (e.g., natural
saline-water seeps, runoff from naturally saline
soil, and evaporation) and man-made (e.g., farming
practices, leaking oil well casings, improper brine
disposal, and leaks caused by over-pressurization
of oil wells).
ARCHER o i CLAY
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Bridgeport
Reservoir,*
Figure 1. Segment 0812 and the wells plugged during the
RRC project.
Texas establishes site-specific chloride water
quality standards for every classified segment in
the state on the basis of physical, chemical, and
biological characteristics. High concentrations of
chloride can negatively affect aquatic life, recre-
ation, public water supply, and other beneficial
uses of water resources. They can make drinking
water unpalatable by causing a brackish, briny taste.
Levels of chloride and TDS that are too high or too
low can reduce the efficiency of wastewater treat-
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ment plants, as well as the operation of industrial
processes that use raw water.
Chloride is one of the substances that contribute to
the IDS content of water. Corrosion or encrustation
of metallic surfaces by waters high in IDS causes
problems with industrial equipment and boilers,
domestic plumbing, and home appliances that
use water. IDS also affects water clarity. Higher
IDS decreases the passage of light through water,
thereby slowing photosynthesis by aquatic plants.
Furthermore, water with high IDS levels heats up
more rapidly and holds more heat, which might
adversely affect aquatic life that has adapted to a
lower temperature regime.
Project Highlights
The Railroad Commission of Texas (RRC) worked
with TCEQ and the U.S. Environmental Protection
Agency to use CWA section 319 funds to develop
a saltwater minimization project in Archer and Jack
counties, the area that includes segment 0812. The
project, launched in 2004, was designed to address
TDS and chloride contamination from oilfield activi-
ties in the Trinity River drainage basin. To reach this
goal, the primary objective was to seal abandoned,
unplugged, noncompliantoil and gas wells and to
reseal improperly plugged wells.
From May 2004 until August 2007, RRC sealed 436
wells in Archer and Jack counties, 98 of which were in
the segment 0812 watershed (see Figure 1). Beginning
in 2003, the Texas State Soil and Water Conservation
Board (TSSWCB) partnered with the Jack and Archer
counties' soil and water conservation districts
(SWCDs) and local landowners to implement BMPs
in the watershed. During that effort, 15 water quality
management plans, encompassing 7,204 acres, were
developed and certified. TSSWCB and the SWCDs
provided education and outreach by offering technical
assistance to watershed landowners.
Results
TCEQ collected water quality monitoring data on
West Fork Trinity River segment 0812 between
December 1, 2003, and November 30, 2010. The
data (provided in Figure 2) included 13 sample
results from TCEQ station 10972, two from station
18058, and two from station 18059. The mean chlo-
ride concentration for these stations was 84 mg/L,
below the site-specific mean standard of 100 mg/L
Concentration (mg/L)
Segment 081 2 Chloride Grab Samples
410972 D18058 A18059 Chloride Standard
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Figure 2. Chloride grab samples taken between 1991 and
2012 atTCEQ stations 10972, 18058, and 18059.
for the assessment period; therefore, segment 0812
was removed from Texas' 2012 CWA section 303(d)
list of impaired waters.
Between December 1, 2010, and August 21, 2012,
TCEQ collected eight samples at station 10972. The
site had a mean chloride concentration of 17 mg/L
for that period, which shows ongoing improve-
ment and indicates that chloride levels are likely to
continue meeting water quality standards during
the upcoming 2014 assessment.
Partners and Funding
Funding for the well-plugging effort (initiated in
2004) was provided by the U.S. Environmental
Protection Agency ($600,000 in CWA section 319
funds) and RRC ($481,430 in matching funds,
including $243,144 from the Texas Oil Field Cleanup
[OFCU] Fund). Funding for voluntary BMP imple-
mentation, as well as for education and outreach to
agricultural producers, included $100,000 in CWA
section 319 funds, more than $41,300 in state funds
from TSSWCB, and over $45,000 in matching funds.
Since 1965 the state of Texas has maintained a
well-plugging program through the OFCU Fund. A
report developed by RRC in January 2000, entitled
Oil and Gas Well Plugging in Texas, states that
CWA section 319 funding, along with other funding
initiatives, is "extremely important since there are
insufficient funds in the OFCU Fund to plug all the
abandoned wells in a reasonable period of time."
ss
HI
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-14-001G
March 2014
For additional information contact:
Tim Cawthon
Texas Commission on Environmental Quality
Nonpoint Source Program
512-239-0845 • tim.cawthon@tceq.texas.gov
T.J. Helton
Texas State Soil and Water Conservation Board
Nonpoint Source Management Program
254-773-2250 • thelton@tsswcb.texas.gov
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