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NONPOINT SOURCE SUCCESS STORY
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Source Identification and Targeted Actions Reduce Bacteria in the
Bear Creek Watershed
Waterbody Improved KerrGulch and SwedeGulch ln the Bear
listed by the Colorado Water Quality Control Division (division) on
the 2010 Clean Water Act section 303(d) list of impaired waterbodies due to non-attainment of the
Escherichia coii bacteria water quality standard. Following this listing, the Bear Creek Watershed
Association (BCWA) identified potential sources off, coli and partnered with local landowners to
relocate livestock operations, which had been determined to be a primary source. Recent data show
Kerr Gulch and Swede Gulch now attain the E. coli water quality standard, resulting in removal of the
waterbody segment from the section 303(d) list in 2016.
Problem
Downstream of its confluence with Swede Gulch, Kerr
Gulch flows Into Bear Creek approximately one mile
east of Kittredge, Colorado (20 miles west of Denver).
Kerr Gulch and Swede Gulch include approximately
seven linear stream miles within a watershed encom-
passing approximately 2,500 acres (Figure 1).
Between 2003 and 2008, the division assessed data
collected at the mouth of Kerr Gulch. The six water
samples collected had a geometric mean of 271 colo-
ny-forming units per 100 mL of water (CFU/100 mL),
which exceeded the E. coli recreational use water
quality standard of 126 CFU/100 mL. This resulted in
the CWA section 303(d) listing of the Kerr/Swede gulch
system (segment COSPBE05_0501).
The Bear Creek watershed is home to many who enjoy
life in the foothills immediately west of Denver; it is
also frequently visited by outdoor enthusiasts from
the nearby urban corridor. To minimize the potential
impacts to residents and recreationalists from the
elevated levels of E. coli in Kerr and Swede gulches,
BCWA initiated a project to investigate nonpoint
sources of bacteria in the watershed and to prioritize
actions to address these sources.
Project Highlights
As part of the project, BCWA collected water quality
samples to better understand E. coli in the Kerr/Swede
system (Figure 2). The project also investigated poten-
tial E. coli nonpoint sources based on water quality
Figure 1. The Kerr Gulch/Swede Gulch watershed
drains into Bear Creek in central Colorado.
data from these sampling locations and land uses. The
two potential nonpoint sources identified were on-site
wastewater treatment systems (OWTS) and horse
stabling operations.
In collaboration with BCWA, Jefferson County Public
Health Department investigated the OWTS in the area
and found no obvious system failures, making OWTS
sources a lower priority for additional action.
To investigate the potential horse stabling sources,
BCWA identified multiple horse operations proximal
to Kerr and Swede gulches, in 2011 BCWA began
conversations with the owners of these operations
to discuss the potential for runoff of E. coli and other
nonpoint source pollution. As one of the outcomes of
the outreach efforts by BCWA, two stabling operations
Bear Creek
HUC12 Watershed 101900020805
Legend
C3 Bear Creek HUC 12 Watershed 101900020805
Area Enlarged
Colorado

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Legend
• Sampling Sites
O Horse Stables
Kerr Gulch
BCWA Site 55 (Swede Gulch)
BCWA Site 54 (Kerr Gulch)*
BCWA Site 53
COLORADO
Department of Public
Figure 2. Sampling sites and potential bacteria sources
in Kerr and Swede gulches.
were Identified as likely sources of E. coli; these were
targeted for source removal (Figure 3). In 2013 BCWA
worked with these owners to alter their operations to
reduce the potential for E. coli to enter Kerr and Swede
gulches. In one instance, the stable operator was able
to move the stabling area away from Kerr Gulch to
provide a larger stream buffer between the stabling
operations and the waterway. This operator was also
willing to remove manure stockpiles from a loca-
tion immediately adjacent to the stream. A separate
stabling operation farther upstream in Swede Gulch
voluntarily moved three trailers' worth of manure
away from the stream.
Results
Following project implementation, BCWA continued
to regularly monitor E. coli levels throughout the Kerr/
Swede Gulch system at the same sampling locations.
Whereas water quality data collected by BCWA show
non-attainment of the E. coli water quality standard
in the summer of 2010 and the summer of 2012, after
all investigations and subsequent source removal
activities, no water quality samples showed exceed-
ances of the water quality standard of 126 CFU/100 mL
(Figure 4).
The efforts undertaken by BCWA and landowners in
the watershed resulted in a documented reduction of
E. coli entering Kerr and Swede gulches. BCWA moni-
toring data were subsequently used by the division to
support a 2016 removal of the Kerr Gulch and Swede
Gulch E. coli impairment listing.
U.S. Environmental Protection Agency
Office of Water
\ Washington, DC
WJ
— ----"jf EPA 841-F-17-001U
pRol^° October 2017
Figure 3. BCWA worked with the horse stable
operators to control manure sources near waterways.
Partners and Funding
Source investigation, data analyses and implementa-
tion work were conducted by BCWA. BCWA mem-
bership includes counties, local general-purpose
governments, special districts, local citizen groups
and other agencies. The members work together to
protect and restore water and environmental quality
within the Bear Creek watershed from the effects of
land use. BCWA accomplishes its work in the water-
shed through member dues, member and partner
contributions, and targeted funding opportunities. The
water quality improvements in Kerr and Swede gulches
were the result of landowner in-kind donations and
voluntary land management changes, as well as BCWA
outreach efforts.
250
¦	BCWA Site 52
200
- BCWA Site 53
" BCWA Site 54
150
	BCWA Site 55
- - E. coli Standard
50
Figure 4. E. coli levels in the Kerr/Swede Gulch
watershed declined between 2010 and 2015.
For additional information contact:
Russell Clayschulte
Bear Creek Watershed Association Manager
303-751-7144 • rclayschulte@earthlink.net
Tammy Allen
CDPHE Water Quality Control Division
303-692-3554 • tamara.ailen@state.co.us

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