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Local, Regional and State Partners' Efforts Improve Delaware Creek
\A/ptPrhnfi\•' I m nrnypH oklahoma listed Delaware Creek ori the Clean Water Act (CWA)
section 303(d) list for total dissolved solids (TDS), Escherichia coli, and
phi in 2004 and for turbidity and sulfates in 2008. Oil and gas extraction, illegal dumping, development
and grazing contributed to these impairments. Remediating active and abandoned oil and gas sites,
implementing conservation practices (CPs), and educating citizens and agencies resulted in improved
land management practices and reduced illegal dumping, which decreased salt, sediment, bacteria and
nutrient loading. As a result, the entire length of Delaware Creek was removed from Oklahoma's CWA
section 303(d) list for pH (2006), E, coli (2008), TDS (2010), sulfates (2010), and turbidity (2012).
Problem
Delaware Creek is a 26.3-mile stream in Osage and
Tulsa counties in northeastern Oklahoma. Land use
in the 33,000-acre watershed is approximately 40%
pasture and 54% forested. Less than 5% is developed.
Oil and gas production is significant in the watershed
(Figure 1). Poor management of agricultural and well-
drilling areas contributed to degraded water quality,
and its location nearTulsa made it a prime spot for
illegal dumping at bridge crossings. After data showed
violations of water quality standards in Delaware
Creek, Oklahoma added the entire length of the creek
(OK121300010150_00) to the CWA 303(d) list for
numerous parameters: pH (2006), E. coli (2008), TDS
(2010), sulfates (2010), and turbidity (2012) (Table 1).
It is also listed as impaired for chloride (2004),
dissolved oxygen (2004), and for nonsupport of
benthic macroinvertebrates (2012).
Table 1. Delaware Creek assessment and CWA section 303(d) listing details.
Figure 1. The Delaware Creek watershed is in an oil and gas
resource-rich area of eastern Oklahoma, with more than 1,651
known wells drilled in the watershed. Over 80% of those wells
remain active; 3% have been plugged.
Impairment
Applicable water quality standard
Listing date and justification
Delisting date and justification
Total dissolved
solids
Pre-2010: No more than 396 mg/L;
post-2010: No more than '10% may
exceed 700 mg/L
2004: 63% samples exceeded
WQS (19% exceeded when
post-2010 WQS applied)
2010: From 2010 to 2016,
0% exceeded 700 mg/L;
met WQS
Pathogens
(E. coli)
May not exceed a monthly geometric
mean (geomean) of 126/100 mL
2004: Geomean of 137/100
mL exceeded WQS
2008: Geomean of 98/100
mL; met WQS
pH
No more than 10% of samples may be
outside of 6.5 - 9
2004: 12% of samples
exceeded WQS
2008: 10% were outside
range; met WQS
Turbidity
No more than 10% of seasonal baseflow
samples may be above 50 NTU
2008: 11% of samples
exceeded WQS
2012: 5% of samples
exceeded 50 NTU; met WQS
Sulfates
Pre-2008, no more than 10% of samples
could exceed 65 mg/L; post-2008,
sample average cannot exceed 65 mg/L
2008: 24% of samples
exceeded WQS
2010: sample average was
56 mg/L; met WQS
Delaware Creek Watershed
Oil and Gas Wells
scale: 1:53,000
Tulsa County
Oil & Gas Wells
STATUS
#	Active
Plugged & Abandoned
Spudded
•	Unknown
Delaware Creek
and Tributaries
Delaware Creek
Q Watershed
Delaware Creek Bridges
Notes: mg/L = milligrams per liter; mL = milliliters; l/VQS = water quality standards; NTU = nephelometric turbidity units

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Project Highlights
Delaware Creek, E. coli
Landowners implemented CPs with assistance
from the Oklahoma Conservation Commission's
(OCC) Locally Led Cost Share (LLCS) program and
through the U.S. Department of Agriculture's Natural
Resources Conservation Service (NRCS) Environmental
Quality Incentives Program (EQIP) and Conservation
Stewardship Program (CSP). Beginning in 2004, land-
owners installed 79 acres of prescribed grazing, 41 acres
each of forage and biomass planting, 55 acres of nutri-
ent management, seven ponds, 59 acres of upland wild-
life habitat management, 1 acre of critical area planting,
2,463 linear feet of cross-fencing, 81 acres of rotation
of supplement and feeding areas, and 110 acres of alley
cropping. Landowners also implemented modified tim-
ing of fertilizer applications on 31 acres, integrated pest
management on 186 acres, crop rotation and use of
deep-rooted crops and reduced tillage on 17 acres, and
improved irrigation efficiency on 13 acres.
The Indian Nations Council of Governments (INCOG)
published a 2012 study which characterized the extent
of DO problems in the watershed and evaluated
contributing factors. In 2016, INCOG summarized oil
and gas activity in the watershed to evaluate potential
causes of salt contamination and actions that likely
contributed to improvements. Although DO concentra-
tions remain impacted by morphology of the stream
and the lack of summer flow, DO has improved. INCOG
has noted a gradual decrease in illegal dumping, per-
haps due to education efforts and increased presence
of agency personnel in the watershed.
The Oklahoma Energy Resources Board (OERB)
restores abandoned oil and gas sites by removing
abandoned equipment and contaminated materi-
als and regrading and revegetating sites. OERB has
restored 11 watershed sites since 2006. The Oklahoma
Corporation Commission (Corp. Comm.) regulates oil
and gas activities, including environmental sampling,
permitting and response to complaints. Since the early
2000s, Corp. Comm. has conducted water quality
monitoring and has overseen one enforcement and
remediation case in the watershed.
The Oklahoma Blue Thumb Program maintained
active volunteer monitoring sites on Delaware Creek
between 1996 and 2010. Volunteers collect monthly
water quality information and educate their communi-
ties about the importance of protecting water quality.
Max = 2400
3eomean=
o 350
„ 250
ICC
Max = 2400 Max = 1000
Geomean= Geomean=
98	112
Geomean= Geomean=
0
lil
2008	2010	2014	2016
Figure 2. Monitoring data show improved E. coli levels.
Results
The OCC documented improved water quality through
its monitoring program in turbidity, TDS, pH, sulfates,
and E. coli (see Table 1, right column). Figure 2 shows
E. coli levels over time. On the basis of these data,
Oklahoma removed the following impairments from
the state's CWA section 303(d) list: pH (2006), E. coli
(2008), TDS (2010), sulfates (2010), and turbidity
(2012). Delaware Creek remains listed for chloride,
dissolved oxygen, and benthic macroinvertebrates.
Partners and Funding
The OCC monitoring program is supported by the U.S.
Environmental Protection Agency's (EPA) CWA section
319 funds at an average annual statewide cost of
$1 million; approximately $500,000 in EPA section 319
funds support statewide Blue Thumb. The OCC LLCS
program provided $6,709 in state funding for CPs in
this watershed through the Osage and Tulsa county
conservation districts; landowners contributed an
additional $6,854 in match. Beginning in 2004, NRCS
supplied less than $215,000 to implement CPs in the
watershed through NRCS EQIP and CSP. A large num-
ber of practices were funded by landowners based
on recommendations through NRCS general technical
assistance and conservation planning. INCOG invested
at least $20,000 through an EPA CWA section 604(b)
project to characterize the water quality problems in
the watershed. OERB invested at least $105,000 to
restore abandoned oil and gas sites in the watershed.
OCC's activities have also played an important role in
the water quality improvement.
^edsj^ U.S. Environmental Protection Agency
0** Office of Water
^ Washington, DC
WJ
EPA 841-F-16-001Y
pro^° October 2016
For additional information contact:
Shanon Phillips
Oklahoma Conservation Commission
405-522-4500 • shanon.phillips@conservation.ok.gov

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