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Section 319
NONPOINT SOURCE PROGRAM SOCGESS STORY
Watershed Approach Reduces Pollution in the Tualatin River/
Watorhnrlioc ImnrnwoH NonP°int and P°int sources of pollution caused water quality
VVdLWlUUUlWb III npiuvwu problems in Oregon's Tualatin River basin. As a result, between
1998 and 2002 the Oregon Department of Environmental Quality (ODEQ) added 31 segments to
the state's Clean Water Act section 303(d) list of impaired waters for one or more of the following
pollutants: temperature, bacteria, dissolved oxygen, chlorophyll a, toxics (arsenic, iron and manganese),
biological criteria and low pH. Using a watershed-based approach, stakeholders have upgraded
wastewater treatment plants, restored riparian areas, and implemented agricultural and urban best
management practices (BMPs). Data show that levels of many pollutants have declined significantly.
Problem
The Tualatin River drains 27 sub-basins across
a 712-square-mile area and empties into the
Willamette River in the northwest corner of Oregon
(Figure 1). The basin is fairly evenly divided among
forest (39 percent), agriculture (35 percent) and
urban (26 percent) land uses.
Wastewater treatment plant discharge and runoff
from agricultural, forested and urban areas con-
tributed multiple pollutants to the Tualatin River.
Low dissolved oxygen, elevated pH and high
chlorophyll a levels in the river prompted ODEQ
to develop total maximum daily loads (TMDLs) for
ammonia and phosphorus in 1988. In 2001 ODEQ
revised those TMDLs and developed newTMDLs
for additional parameters (temperature, bacteria and
dissolved oxygen). By 2002, 31 segments across
27 Tualatin River sub-basins had been identified as
impaired for one or more parameters.
Project Highlights
Efforts to improve water quality have been under-
way over the last few decades. The Tualatin River
Watershed Council (TRWC), a local watershed
stewardship organization, has been working with
landowners to implement restoration projects since
1993. In 2001 ODEQ and other watershed stake-
holders developed the Tualatin River Water Quality
Management Plan, which outlined a strategy for
achieving the load allocations outlined in the basin's
TMDLs.
The Oregon Watershed Enhancement Board
(OWEB), a state agency led by a 17-member citizen
board, uses funds from the Oregon Lottery, federal
programs and salmon license plate revenue to
provide watershed restoration grants. Between
2004 and 2009, the OWEB grant program sup-
ported 186 Tualatin River basin projects to restore
Figure 1. The lower Tualatin River, near Sherwood,
Oregon.
and protect stream channels and riparian, upland,
wetland and urban areas.
In 2004 Clean Water Services (CWS), a special
service district that provides wastewater and
stormwater services to more than 520,000 people,
was issued a watershed-based National Pollutant
Discharge Elimination System (NPDES) permit. The
permit provides unique opportunities for CWS to
improve the water quality in the Tualatin River basin
by allowing the trading of carbonaceous biological
oxygen demand and nitrogenous oxygen demand
within and between the four wastewater treatment
plants (WWTPs).
The permit enables CWS to generate water quality
credits by planting riparian areas in the rural and
urban portions of the basin and augmenting stream
flow. The credits are used to offset the excess
thermal loads from the WWTPs. Between 2004 and
2010, CWS implemented 44 projects (covering 17.1
stream miles) in urban areas. The projects included
riparian planting and stream enhancement activi-
ties. In rural areas, CWS contracted with the Tualatin
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Soil and Water Conservation District (SWCD) to
provide incentives (rental payments and restoration
assistance teams) that encouraged landowners to
enroll in a modified version of the U.S. Department
of Agriculture's (USDA's) Conservation Reserve
Enhancement Program and Vegetated Buffer Areas
for Conservation and Commerce Program. Between
2004 and 2010 CWS and the Tualatin SWCD used
those programs to implement 33 riparian plant-
ing projects in rural areas, which revegetated
19.3 stream miles, thereby reducing in-stream
temperature and generating 329 million kilocalories
of shade credit. The riparian planting efforts also
help to filter stormwater runoff and reduce erosion,
thereby reducing the levels of phosphorus, sedi-
ment and bacteria reaching surface waters.
From 2007 to 2011, the Tualatin SWCD worked with
landowners to complete 30 farm water quality plans
covering almost 1,500 acres. The USDA Natural
Resources Conservation Service (NRCS), Tualatin
SWCD, Metro Regional Government, and the
U.S. Fish and Wildlife Service (USFWS) implement-
ed more than a dozen wetland restoration projects
covering more than 1,000 acres.
Results
Tualatin River Sub-basins—Improving Water Quality Trends (1992-2011)
Legend
•—| No improving trends, no
'—' impaired waters or no data
I—| Improving trends in
1—' impaired waters
Pollutants Showing Decreases
• Phosphorus
• f.Co/1
• Chlorophyll a
Figure 2. Water quality has improved throughout much of the Tualatin River watershed.
Thanks to a basin-wide restoration effort, water
quality in the Tualatin River watershed has sig-
nificantly improved since the first TMDLs were
adopted in 1988. The incidence of algae blooms in
the lower river has decreased, as demonstrated by
lower chlorophyll a concentrations, no pH violations
and higher minimum dissolved oxygen levels. These
improvements coincide with lower total phosphorus
concentrations, which now meet the 2001 TMDL
phosphorus targets in the mainstem Tualatin River.
In 2011 CWS performed trend analyses on total
phosphorus, bacteria and chlorophyll a data col-
lected from 1992 through 2011. A seasonal Kendall
trend test showed significantly improving trends
(at a 90 percent confidence level or greater) in one
or more pollutants contributing to impairments in
20 of 27 Tualatin River sub-basins (Figure 2). Data
show that some segments listed as impaired now
meet TMDL targets or water quality standards for
one or more parameters. Oregon will begin investi-
gating whether these parameters may be removed
as sources of impairment from listed segments in
an upcoming assessment cycle.
Partners and Funding
Many agencies and organizations
have contributed to the restora-
tion of the Tualatin River basin,
including the ODEQ; CWS; NRCS;
OWEB, USFWS, Tualatin SWCD;
TRWC; Tualatin Riverkeepers;
Oregon Department of Agriculture;
Oregon Department of Forestry;
Multnomah, Clackamas and
Washington counties; and the cit-
ies of Portland, West Linn and Lake
Oswego. Between 1991 and 2001,
ODEQ provided more than more
than $300,000 in section 319 funds
to support BMP implementation
and education projects. Between
1996 and 2009, OWEB partnered
with basin groups, federal and
state agencies, and landowners
to invest $7 million (plus another
$870,000 in-kind matching funds)
in restoration projects. CWS spent
$325 million to upgrade its WWTPs
(in response to the 1988 TMDL),
and spent an estimated $10 to
$12 million to implement restoration
projects between 2005 and 2009.
MULTNOMAH
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-12-001D
March 2012
For additional information contact:
Avis Newell
Tualatin Basin Coordinator
Oregon Department of Environmental Quality
503-229-6018 • Newell.Avis@deq.state.or.us
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