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Implementing Green Inirastructure Projects Improved Water Quali
in the Rahway River
Waterbody Improved
Extensive urbanization resulting in a severely degraded stream
corridor led the New Jersey Department of Environmental
Protection (NJDEP) to add the lower section of the Rahway River to the 2012 Clean Water Act (CWA)
section 303(d) list for dissolved oxygen impairment. Green infrastructure practices implemented
in the Robinsons Branch watershed (an upstream tributary) reduced the amount of untreated
stormwater runoff entering the lower Rahway River. As a result, dissolved oxygen levels in the
river increased, which prompted NJDEP to remove the Rahway River (below Robinsons Branch)
assessment unit from the 2014 CWA section 303(d) list for the dissolved oxygen impairment.
Problem
The 24-mile-long Rahway River begins in Union
Township in northeastern New Jersey and empties into
Arthur Kill, a tidal strait/navigational channel between
New Jersey and Staten Island, New York (Figure 1).
Tides influence the lower Rahway River from the
Pennsylvania Railroad Bridge at the City of Rahway
down to the river's mouth.
The Rahway River is impaired by a variety of pollut-
ants. The NJDEP included multiple assessment units
on the state's 2012 CWA section 303(d) list of impaired
waters, including a low dissolved oxygen impairment
isting for the Rahway River (below the Robinsons
Branch) assessment unit (hydrologic unit code [HUC]
02030104050100).
The Robinsons Branch watershed encompasses
approximately 22 square miles within densely devel-
oped Union and Middlesex counties in New Jersey.
Because urban land uses comprise more than 80 per-
cent of the Robinsons Branch watershed, a significant
cause of the impairments in the downstream Rahway
River is the extensive impervious area that drains
directly to the waterbody.
Story Highlights
In October 2008, Rutgers University completed the
Robinsons Branch Regional Stormwater Management
Plan (a watershed-based plan) to address urban runoff
in the Robinsons Branch watershed. The plan outlined
Rahway River
)
1
A \ Rahway River

/ / S \.
Legend
a Restoration Projects n
% Monitoring Location A
¦ Water Bodies
l^HUC 14 Improved (02030104050100)
¦ ¦ ¦
f 1 HUC 14 Boundaries 0 0.4 0.8
1.6 Miles
Figure 1. The Rahway River (below the Robinsons Branch)
assessment unit, shown in light green, is in northeastern
New Jersey, it is immediately downstream of numerous
green infrastructure restoration projects that were
installed aiong the upstream tributary of Robinsons Branch.

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ytf-r/y.
POROUS ASPHALT
RAIN GARDLN
CONCRETF WASH PAD
CISTERN
Figure 2. Practices included porous asphalt areas that
allow stormwater runoff to infiltrate into the ground
instead of draining directly to streams,
opportunities for the implementation of stormwater
best management practices (BMPs) and management
strategies to reduce peak flows from high-frequency
storms. The pian identifies urban runoff as a significant
source of pollutants, including those that affect dis-
solved oxygen levels.
Project sites for the implementation of green
infrastructure were identified and prioritized in the
approved plan. Rutgers, along with local stakeholders,
began implementing the plan in 2010. BMPs that
were adopted as part of the Regional Stormwater
Management Plan include installing porous pavement
in numerous parking lots, driveways, and recreational
areas; constructing rain gardens in residential
areas and a public park; and collecting and reusing
stormwater (Figure 2). For example, partners installed
a "green" car wash system, which includes a 5,000
gallon cistern that collects stormwater from the
roof of the public works building for use in washing
vehicles, a concrete vehicle wash pad, and a rain
garden for treatment (Figure 3).
In addition to on-the-ground work, education and
outreach was also facilitated within the Robinsons
Branch Watershed. In 2014, 25 municipal representa-
tives participated in a course on rain garden design
and installation methods. They toured rain gardens
and spoke with residents about their new gardens. As
a result, participants have facilitated the construction
of six additional rain gardens within the watershed.
Figure 3. Practices included a car wash system
comprised of a cistern, concrete wash pad and rain
garden that captures, reuses and treats stormwater.
Results
The Rutgers Cooperative Extension Water Resources
Program and project partners implemented 28 green
infrastructure projects and practices throughout the
Robinsons Branch watershed (see Figure 1). Together
these measures greatly reduced untreated stormwater
runoff from impervious surfaces through infiltration.
The following annual reductions were observed:
1.7 pounds (lbs) of total phosphorus, 118.5 lbs of total
suspended solids, and 954,399 gallons of stormwater
runoff. The latest data from station Njl-IDG-11 show
dissolved oxygen met the corresponding water
quality standard of 3 milligrams per liter (mg/L) for
the 2014 assessment period. As a result, the Rahway
River (beiow Robinsons Branch) assessment unit was
delisted for dissolved oxygen in the 2014 Integrated
Report.
Partners and Funding
Green infrastructure projects were completed by
Rutgers. NJDEP awarded Rutgers $512,000 in CWA
section 319(h) grant funds beginning in 2010. Other
project partners included Rahway City, Rahway River
Watershed Association, Clark Township, and local
landowners. Project partners' significant volunteer
efforts to engage local stakeholders, homeowners,
and the general public played an important role in the
implementation of the BMPs.
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-20-QQ1E
January 2020
For additional information contact:
David McPartland
New Jersey Department of Environmental Protection
609-292-0837 • david.mcpartland@dep.nj.gov

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