Stormwater Management Along our Public Highways
By G. Scott McGowen and Anna Lantin
In the realm of stormwater quality, our public highway systems are one of
the most difficult aspects of our urban environment to manage. The linear
nature of our nationwide highway systems and their intense public use make
pollution prevention a challenge for each of our states.
On the west coast, the California Department of Transportation (Caltrans)
manages about 50,000 miles of highway and freeway lanes serving 30 million
residents across a state that spans approximately 158,300 square miles.
Meeting the challenges of stormwater management for this transportation
network and achieving 2007 EPA Clean Water Act award-winning distinction has
taken years of study, collaboration, partnerships and action. Caltrans has
challenges unlike most agencies, primarily because the property maintained
is linear and widespread, and has multiple crossflows requiring flexibility
in accommodating best management practices (BMPs). No other permit holders
within the state of California, and few within the nation, have a
jurisdiction of this size and complexity. Strategies to control pollutants
of concern vary due to the diversity of geographic, geologic, climatic,
population, and regulatory conditions throughout the 770-mile length of the
state.
As federal environmental regulations based on the Clean Water Act have
evolved to require control of pollutants from our Municipal Separate Storm
Sewer Systems (MS4s), discharges brought under the NPDES permit process have
resulted in a need to find solutions to constant challenges. In California,
the EPA has delegated administration of the federal NPDES program to the
State Water Resources Control Board and potential location-specific
activities from the nine Regional Water Quality Control Boards (RWQCBs).
Biofiltration swale located along Interstate 5 is
designed to remove pollutants from roadway runoff in the coastal area of
northern San Diego County, CA.
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The Statewide Stormwater Management Plan (SWMP) is a requirement of the
permit, which Caltrans has developed into the greatest benefit and guiding
force of the program. The plan addresses stormwater and authorized non-stormwater
discharges to waters of the United States as defined by U.S. EPA and waters
of the state of California as defined by the Porter-
Cologne Act.
Caltrans, through this detailed SWMP and associated innovative
technologies, is emerging as a recognized leader in the field, while
continually seeking ways of meeting these challenges with solutions that can
be applied nationwide. As the key to the program’s progress and success, the
SWMP addresses the programmatic approach for achieving compliance with state
and federal requirements for the protection of water quality.
The first statewide SWMP was developed and implemented in March 1997,
with the current plan developed and submitted on January 15, 2004, to renew
the Caltrans statewide NPDES permit. A revised, updated SWMP was submitted
in June 2007.
The SWMP addresses discharges resulting from stormwater originating from
precipitation and snowmelt and non-stormwater discharges including illicit
and authorized discharges and emergency response activities. The California
Streets and Highway Code defines “highway” to include bridges, culverts,
curbs, drains and all works incidental to highway construction, improvement
and maintenance. Contribution of pollutants from all of these areas is under
the authority of Caltrans.
Earthen side sloped partial sedimentation sand filter
BMP located along Interstate 5 is designed to protect the quality of
water entering adjacent rivers and streams from roadway stormwater
runoff in northern California. |
The Caltrans Stormwater Program has taken the approach of looking at the
full spectrum of activities, including planning, design, construction,
maintenance and operation of roadways and facilities. The Stormwater
Management Plan addresses responsibilities of Caltrans for implementing
stormwater management procedures and practices including training, public
education, monitoring, program evaluation, BMP development and reporting
activities on a statewide basis.
Caltrans BMP site located off the 241 Toll Road in
Orange County, CA.
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Important aspects of the program include its management and delegation of
responsibility. Stewardship and management of the program begins with the
six divisions dedicating staff to address stormwater issues (Environmental
Engineering, Design, Construction, Maintenance, Right-of-Way and Traffic
Operations/Encroachment Permits) lead by the Headquarters Division of
Environmental Analysis in Sacramento. Each division is responsible for tasks
related to the division’s core activities, such as developing tools,
guidance and manuals, training, and administration of a Stormwater Advisory
Team (SWAT). The state is divided into twelve Caltrans districts, each of
which has responsibility for day-to-day, project-based implementation of the
plan.
Each division SWAT is made up of representatives from the twelve
districts statewide, which come together for review of proposed and existing
BMPs and process and implementation of the SWMP to gain a statewide
perspective. This allows each division to evaluate the applicability and
workability of the BMPs to develop practical solutions to stormwater issues.
Each division develops training for its unique area. The Stormwater Advisory
Teams meet independently and then come together annually in a large “Super
SWAT” to discuss the issues across the state.
This results in an integrated approach to accomplishing the goals of the
statewide stormwater management program and a team synergy among the
functional areas and geographic regions, resulting in better communication,
improved design and quality control through an informed approach on the part
of all Stormwater Advisory Team members.
Important components of the stormwater program also include the new BMPs
and the Monitoring and Discharge Characterization Program, which addresses
storm drain system inventories and discharge characterization studies; BMP
development, addressing the prioritization, evaluation, adoption and
integration of approved design BMPs; facilities operations; public education
and participation, which includes use of outreach, mass media, including the
“Don’t Trash California” campaign, and public participation programs;
location-specific activities and the program evaluation, which highlights
field activities compliance evaluation and project design compliance
evaluation; and measurable objectives, a performance-based approach and
comprehensive list measuring achievement of the program activities, tasks
and schedule for the program development.
Studies and BMP development information are made available to everyone
within the departments through the Web to keep new information available to
all members of the program.
Throughout the program, Caltrans has created new and improved program
components, designed technologies and approved new BMP devices for
implementation, conducted a variety of research studies on highway runoff,
executed a multimillion dollar public education campaign, trained statewide
personnel, garnered partnerships with other stakeholders, and participated
in implementing programs with a watershed emphasis.
Developing a high-level program and participating with local and state
agencies on a watershed basis has resulted in a cost-effective and
well-rounded program in California to meet the challenges of stormwater
management along our public highways. Caltrans has implemented and continues
to enhance this unique and advanced program of stormwater quality and
management that transportation agencies nationwide can use as a valuable
resource.
- G. Scott McGowen, P.E., is the chief environmental engineer in the
Division of Environmental Analysis for Caltrans Headquarters in
Sacramento, CA. He is the leader of the Stormwater Program for the state.
- Anna Lantin, P.E., is the vice president of stormwater quality with
RBF Consulting in Irvine, CA. She has worked with Caltrans on its
stormwater program since its inception.
Urban Water Management February, 2008
Author(s) : Anna Lantin
G. Scott McGowen
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