files/G2r4xF55StyimUmUJvAc ridgway
em • case study
®
Stormwater Management under NPDES Phase II at Purdue University
by Robin Ridgway, Jim Knapp, and Barb Mansfield
Stormwater runoff, once an unused byproduct of snowmelt and powerful rainstorms, has become a valuable resource at Purdue University’s West Lafayette, IN, campus. A portion of the campus’s stormwater runoff is no longer diverted off-site; it is put to a variety of uses thanks to Purdue
Robin Mills Ridgway, Ph.D., P.E., is the director of environmental health and safety regulatory compliance in physical facilities at Purdue University. She earned her master’s and Ph.D. degrees in environmental engineering from Purdue University, is a licensed professional engineer in Indiana, and is also a LEED accredited professional. Jim Knapp, P.E., is the senior civil engineer in physical and capital planning at Purdue University. He has degrees in civil engineering and biology, is a licensed professional engineer in Indiana, is a LEED accredited professional, and is the stormwater coordinator for Purdue University. Barb Mansfield was a capital project manager for Purdue University. E-mail: rmridgway@ purdue.edu.
implementing innovative strategies to comply with the U.S. Environmental Protection Agency’s National Pollutant Discharge Elimination System (NPDES) Phase II stormwater regulations.
Purdue University’s approximately 2,600-acre West Lafayette campus is located in the Wabash River watershed in north central Indiana. Like many large universities in urbanized areas, Purdue is a regulated Municipal Separate Storm Sewer System, or “MS4,” under the NPDES Phase II stormwater program. Purdue’s MS4 regulatory obligations necessitate long-term planning and led the university to develop a strategy for comprehensive stormwater management that includes community interactions. This first step of evaluating the university’s compliance obligations was to determine the scope of the university’s responsibility for storm sewers. Because regional stormwater flows through both city-owned and university-owned storm sewers, delineating compliance obligations based on storm sewer ownership presented a challenge. Leveraging the relationships Purdue University has with the City of West Lafayette, Tippecanoe County, and the neighboring communities of Lafayette, Battleground, and Shadeland, Purdue became a participant in one of only a few shared MS4 permits in Indiana. The Tippecanoe County Surveyor at the time of the initial permit issuance had a keen sense for the advantage of community cooperation and was very influential in gaining the participation of all local government representatives. The groups saw that by working together they could achieve mutual benefits and potentially pass on cost savings to local citizens. As a result, the Tippecanoe County Partners in Water Quality (TCPWQ) group was formed. In 2005, the Indiana Association for Floodplain and
24 em june 2013
Stormwater Management (INAFSM) recognized this unique relationship and awarded Purdue and its co-permittees the 2005 Outstanding Stormwater Project Award. In the years preceding the implementation of NPDES Phase II, the university’s goal was to convey stormwater off-site as expeditiously as possible—a typical approach used in urbanized areas. NPDES Phase II compliance strategies encouraged Purdue to seek alternative approaches to stormwater management. Purdue began to approach stormwater as a resource that when managed properly could minimize risk to groundwater-sourced drinking water supplies and to the water quality of the neighboring Wabash River. Since rainfall and stormwater runoff recharge the groundwater, it is important that these sources are allowed to permeate the ground, and in the case of stormwater runoff, to be cleaned beforehand. To ensure that new projects properly consider stormwater impact, Purdue adopted the local TCPWQ stormwater quality ordinances and incorporated best practices into the campus’s Design Standards, the guide for all campus project design and construction. All projects greater than one-half acre in size are required to comply with the local ordinances. In 2009, Purdue developed a campus-wide Sustainable Stormwater Modification Design. This document has guided changes to the university’s stormwater treatment practices by encouraging designers to explore alternative strategies. These strategies focus on addressing stormwater closer to
Copyright 2013 Air & Waste Management Association
awma.org
The permeable pavement located near Stadium Mall on Purdue University’s West Lafayette campus allows stormwater to be directly absorbed into the ground. Photo credit: Rebecca Terry/ Purdue University
awma.org
Copyright 2013 Air & Waste Management Association
june 2013 em 25
Purdue’s Program Continues to Meet Its Goals • Since 2007, a total of approximately 12 acres of parking lots and walkways across campus have been upgraded to incorporate porous asphalt, pervious concrete, or permeable pavement. • Since 2006, eight bio-swales and two green roofs have been installed, and a rain garden guided by a student class project is scheduled for completion later in 2013. • Four equipment wash pads are under construction in support of golf course, transportation, and facilities management operations. • Completed in 2009, a 430,000-gallon stormwater infiltration basin lies beneath the football practice field, and the 400-space adjoining parking lot was upgraded to include bio-swales in 2011 that filters the stormwater before it enters the basin.
the source and using natural methods to collect, clean, and reuse the rain water where it falls. The main objectives of the program are as follows:
The green roof at Schleman Hall of Students Services reduces stormwater runoff, improves energy efficiency, and extends the life of the roof by protecting it from the elements. Photo credit: Andrew Hancock/ Purdue University
• Maximize capacity of existing natural systems to perform ecosystem services • Improve and protect water quality and groundwater resources • Manage stormwater as an opportunity, not a problem • Strive to balance the stormwater impact of the campus footprint with that of a predevelopment model for the area • Increase awareness of Purdue’s water resources, and the groundwater and rainfall relationship • Reinforce Purdue’s position as a water resource management role model for Indiana Through this process, the university has learned that a stormwater system is most effective when it consists of a number of smaller stormwater treatments, such as permeable pavement, bio-swales,
and rain gardens. Permeable pavement allows stormwater to be absorbed on site before it has the opportunity to become contaminated runoff water. These surfaces typically are made of asphalt, concrete, or brick and have been installed in a variety of locations, including back dock areas of academic buildings, several parking lots, and campus green spaces. Purdue’s Grounds Department regularly cleans the surfaces with a vacuum to maintain good water flow. The staff members are also educated on the dangers of accidental chemical or fuel spills on the permeable surfaces and are advised to avoid these areas if the potential for a chemical spill exists. When stormwater cannot be absorbed directly on site, a best practice is to install a device to treat the stormwater before it is released into the storm sewer. Some standard engineering solutions include sediment traps and filters, as well as oil/water separators. Through implementation of its Sustainable Stormwater Modification Design, Purdue has opted to install natural treatment systems in the form of bioswales and rain gardens. Bio-swales are sloped landscapes that are planted with native grasses and plants that naturally filter, clean, and slow down stormwater runoff before redirecting it to another location, such as a more traditional stormwater inlet. Rain gardens collect stormwater runoff using native plants that can tolerate excess water, cleanse the water, and encourage the water to infiltrate the ground. New projects must comply with the Sustainable Stormwater Modification Design and are required to incorporate stormwater best practices into new landscape and sustainability projects (e.g., permeable pavements, infiltration beds, rain gardens, and green roofs). All stormwater best practices are paid for by the project with retrofits and improvements
26 em june 2013
Copyright 2013 Air & Waste Management Association
awma.org
paid for by special funding as opportunities arise. Purdue’s program has enjoyed continued success (see sidebar opposite, “Purdue’s Program Continues to Meet Its Goals”).
Conclusion Stormwater runoff management is only part of the core, or “six minimum control measures,” of Indiana’s NPDES Phase II regulations. Full compliance with the program requires permittees to develop programs in the following areas: • • • • • •
Public Education and Outreach Public Involvement and Participation Illicit Discharge, Detection and Elimination Construction Site Stormwater Runoff Control Post Construction Stormwater Management Pollution Prevention/Good Housekeeping
Purdue University has embraced the NPDES Phase II regulations as a tool for improving stormwater management on campus. Thorough evaluation of possible compliance strategies has led the university to the design and implementation of innovative systems throughout campus, including a shared
MS4 permit holding system and a campus-wide Sustainable Stormwater Modification Design document that resulted in the installation of permeable pavement, bio-swales, and rain gardens. Purdue’s commitment to long-term strategies regarding water resource management has enabled the university to be a leader in stormwater management best practices, making the development of programs to ensure compliance with the rest of the minimum control measures a logical outgrowth of its overall commitment. em
Bio-swales can be found on the West Lafayette campus near both academic buildings and athletic complexes. Photo credit: Andrew Hancock/Purdue University
Understanding Today’s Clean Air Act Permit Programs Get up-to-date Get up-to-date on the latest latest rules impac impacting ting NSR and Title Title V permitting: permitting: the Greenhouse Greenhouse Gas Gas Tailoring Tailor a ing Rule; the New Ozone, Ozone, NO2 and PM2.5 PM2.5 NAAQSs; NAAQSs; modeling; NEP NEPA PA issues; C CAFO AFO sources, sources, and more. more. This This ttwo-day wo-day workshop workshop will cover cover permitting permitting changes presented presented by by both national national and rregional egional leaders in the field field.. Wo orkshop Faculty include: Colin Principal, C olin Campbell, Campbell, P rrincipa all, RTP RTP Environmental Envirronmental o Gale G ale Hoffnagle, Hoffnagle, Senior Senior V Vice iice President Preesident and TTechnical eechnical Director, Directorr, TRC TRC Environmental Envirronmental onment o Corporation C o orporration a Dave Dave Jordan, Jordan, Program Progrram a Director, Dirreectorr, ERM Mark and Compliance Permits e Complianc o e Branch, Brranch, U.S. EPA, EP PA A, Region 7 Mark Smith, Chief of Air Air Permits
UPCOMING W WORKSHOP ORKSHOP
July 23-24, 23-24, 20 2013 13 Kansas Kansas City City,, MO Burns & McDonnell Auditorium 9400 Ward Ward Parkway, Parkway, Kansas Kansas City City,, MO 64 64114 114 Title V PM 2.5
Sponsorship and e exhibit xhibit oppor opportunities tunities ar are e available. available.
8 hr. Ozon e S ndard Sta NS R NSR
REGISTER TOD REGISTER TODAY! AY! Y http://permitting.awma.org http://permitting.a wma.org
awma.org
Copyright 2013 Air & Waste Management Association
R T TR AT CA
as Ga eG usse ou ho nh en ee G Grre ing lorrin aiilo Ta T
june 2013 em 27
®
Stormwater Management under NPDES Phase II at Purdue University
by Robin Ridgway, Jim Knapp, and Barb Mansfield
Stormwater runoff, once an unused byproduct of snowmelt and powerful rainstorms, has become a valuable resource at Purdue University’s West Lafayette, IN, campus. A portion of the campus’s stormwater runoff is no longer diverted off-site; it is put to a variety of uses thanks to Purdue
Robin Mills Ridgway, Ph.D., P.E., is the director of environmental health and safety regulatory compliance in physical facilities at Purdue University. She earned her master’s and Ph.D. degrees in environmental engineering from Purdue University, is a licensed professional engineer in Indiana, and is also a LEED accredited professional. Jim Knapp, P.E., is the senior civil engineer in physical and capital planning at Purdue University. He has degrees in civil engineering and biology, is a licensed professional engineer in Indiana, is a LEED accredited professional, and is the stormwater coordinator for Purdue University. Barb Mansfield was a capital project manager for Purdue University. E-mail: rmridgway@ purdue.edu.
implementing innovative strategies to comply with the U.S. Environmental Protection Agency’s National Pollutant Discharge Elimination System (NPDES) Phase II stormwater regulations.
Purdue University’s approximately 2,600-acre West Lafayette campus is located in the Wabash River watershed in north central Indiana. Like many large universities in urbanized areas, Purdue is a regulated Municipal Separate Storm Sewer System, or “MS4,” under the NPDES Phase II stormwater program. Purdue’s MS4 regulatory obligations necessitate long-term planning and led the university to develop a strategy for comprehensive stormwater management that includes community interactions. This first step of evaluating the university’s compliance obligations was to determine the scope of the university’s responsibility for storm sewers. Because regional stormwater flows through both city-owned and university-owned storm sewers, delineating compliance obligations based on storm sewer ownership presented a challenge. Leveraging the relationships Purdue University has with the City of West Lafayette, Tippecanoe County, and the neighboring communities of Lafayette, Battleground, and Shadeland, Purdue became a participant in one of only a few shared MS4 permits in Indiana. The Tippecanoe County Surveyor at the time of the initial permit issuance had a keen sense for the advantage of community cooperation and was very influential in gaining the participation of all local government representatives. The groups saw that by working together they could achieve mutual benefits and potentially pass on cost savings to local citizens. As a result, the Tippecanoe County Partners in Water Quality (TCPWQ) group was formed. In 2005, the Indiana Association for Floodplain and
24 em june 2013
Stormwater Management (INAFSM) recognized this unique relationship and awarded Purdue and its co-permittees the 2005 Outstanding Stormwater Project Award. In the years preceding the implementation of NPDES Phase II, the university’s goal was to convey stormwater off-site as expeditiously as possible—a typical approach used in urbanized areas. NPDES Phase II compliance strategies encouraged Purdue to seek alternative approaches to stormwater management. Purdue began to approach stormwater as a resource that when managed properly could minimize risk to groundwater-sourced drinking water supplies and to the water quality of the neighboring Wabash River. Since rainfall and stormwater runoff recharge the groundwater, it is important that these sources are allowed to permeate the ground, and in the case of stormwater runoff, to be cleaned beforehand. To ensure that new projects properly consider stormwater impact, Purdue adopted the local TCPWQ stormwater quality ordinances and incorporated best practices into the campus’s Design Standards, the guide for all campus project design and construction. All projects greater than one-half acre in size are required to comply with the local ordinances. In 2009, Purdue developed a campus-wide Sustainable Stormwater Modification Design. This document has guided changes to the university’s stormwater treatment practices by encouraging designers to explore alternative strategies. These strategies focus on addressing stormwater closer to
Copyright 2013 Air & Waste Management Association
awma.org
The permeable pavement located near Stadium Mall on Purdue University’s West Lafayette campus allows stormwater to be directly absorbed into the ground. Photo credit: Rebecca Terry/ Purdue University
awma.org
Copyright 2013 Air & Waste Management Association
june 2013 em 25
Purdue’s Program Continues to Meet Its Goals • Since 2007, a total of approximately 12 acres of parking lots and walkways across campus have been upgraded to incorporate porous asphalt, pervious concrete, or permeable pavement. • Since 2006, eight bio-swales and two green roofs have been installed, and a rain garden guided by a student class project is scheduled for completion later in 2013. • Four equipment wash pads are under construction in support of golf course, transportation, and facilities management operations. • Completed in 2009, a 430,000-gallon stormwater infiltration basin lies beneath the football practice field, and the 400-space adjoining parking lot was upgraded to include bio-swales in 2011 that filters the stormwater before it enters the basin.
the source and using natural methods to collect, clean, and reuse the rain water where it falls. The main objectives of the program are as follows:
The green roof at Schleman Hall of Students Services reduces stormwater runoff, improves energy efficiency, and extends the life of the roof by protecting it from the elements. Photo credit: Andrew Hancock/ Purdue University
• Maximize capacity of existing natural systems to perform ecosystem services • Improve and protect water quality and groundwater resources • Manage stormwater as an opportunity, not a problem • Strive to balance the stormwater impact of the campus footprint with that of a predevelopment model for the area • Increase awareness of Purdue’s water resources, and the groundwater and rainfall relationship • Reinforce Purdue’s position as a water resource management role model for Indiana Through this process, the university has learned that a stormwater system is most effective when it consists of a number of smaller stormwater treatments, such as permeable pavement, bio-swales,
and rain gardens. Permeable pavement allows stormwater to be absorbed on site before it has the opportunity to become contaminated runoff water. These surfaces typically are made of asphalt, concrete, or brick and have been installed in a variety of locations, including back dock areas of academic buildings, several parking lots, and campus green spaces. Purdue’s Grounds Department regularly cleans the surfaces with a vacuum to maintain good water flow. The staff members are also educated on the dangers of accidental chemical or fuel spills on the permeable surfaces and are advised to avoid these areas if the potential for a chemical spill exists. When stormwater cannot be absorbed directly on site, a best practice is to install a device to treat the stormwater before it is released into the storm sewer. Some standard engineering solutions include sediment traps and filters, as well as oil/water separators. Through implementation of its Sustainable Stormwater Modification Design, Purdue has opted to install natural treatment systems in the form of bioswales and rain gardens. Bio-swales are sloped landscapes that are planted with native grasses and plants that naturally filter, clean, and slow down stormwater runoff before redirecting it to another location, such as a more traditional stormwater inlet. Rain gardens collect stormwater runoff using native plants that can tolerate excess water, cleanse the water, and encourage the water to infiltrate the ground. New projects must comply with the Sustainable Stormwater Modification Design and are required to incorporate stormwater best practices into new landscape and sustainability projects (e.g., permeable pavements, infiltration beds, rain gardens, and green roofs). All stormwater best practices are paid for by the project with retrofits and improvements
26 em june 2013
Copyright 2013 Air & Waste Management Association
awma.org
paid for by special funding as opportunities arise. Purdue’s program has enjoyed continued success (see sidebar opposite, “Purdue’s Program Continues to Meet Its Goals”).
Conclusion Stormwater runoff management is only part of the core, or “six minimum control measures,” of Indiana’s NPDES Phase II regulations. Full compliance with the program requires permittees to develop programs in the following areas: • • • • • •
Public Education and Outreach Public Involvement and Participation Illicit Discharge, Detection and Elimination Construction Site Stormwater Runoff Control Post Construction Stormwater Management Pollution Prevention/Good Housekeeping
Purdue University has embraced the NPDES Phase II regulations as a tool for improving stormwater management on campus. Thorough evaluation of possible compliance strategies has led the university to the design and implementation of innovative systems throughout campus, including a shared
MS4 permit holding system and a campus-wide Sustainable Stormwater Modification Design document that resulted in the installation of permeable pavement, bio-swales, and rain gardens. Purdue’s commitment to long-term strategies regarding water resource management has enabled the university to be a leader in stormwater management best practices, making the development of programs to ensure compliance with the rest of the minimum control measures a logical outgrowth of its overall commitment. em
Bio-swales can be found on the West Lafayette campus near both academic buildings and athletic complexes. Photo credit: Andrew Hancock/Purdue University
Understanding Today’s Clean Air Act Permit Programs Get up-to-date Get up-to-date on the latest latest rules impac impacting ting NSR and Title Title V permitting: permitting: the Greenhouse Greenhouse Gas Gas Tailoring Tailor a ing Rule; the New Ozone, Ozone, NO2 and PM2.5 PM2.5 NAAQSs; NAAQSs; modeling; NEP NEPA PA issues; C CAFO AFO sources, sources, and more. more. This This ttwo-day wo-day workshop workshop will cover cover permitting permitting changes presented presented by by both national national and rregional egional leaders in the field field.. Wo orkshop Faculty include: Colin Principal, C olin Campbell, Campbell, P rrincipa all, RTP RTP Environmental Envirronmental o Gale G ale Hoffnagle, Hoffnagle, Senior Senior V Vice iice President Preesident and TTechnical eechnical Director, Directorr, TRC TRC Environmental Envirronmental onment o Corporation C o orporration a Dave Dave Jordan, Jordan, Program Progrram a Director, Dirreectorr, ERM Mark and Compliance Permits e Complianc o e Branch, Brranch, U.S. EPA, EP PA A, Region 7 Mark Smith, Chief of Air Air Permits
UPCOMING W WORKSHOP ORKSHOP
July 23-24, 23-24, 20 2013 13 Kansas Kansas City City,, MO Burns & McDonnell Auditorium 9400 Ward Ward Parkway, Parkway, Kansas Kansas City City,, MO 64 64114 114 Title V PM 2.5
Sponsorship and e exhibit xhibit oppor opportunities tunities ar are e available. available.
8 hr. Ozon e S ndard Sta NS R NSR
REGISTER TOD REGISTER TODAY! AY! Y http://permitting.awma.org http://permitting.a wma.org
awma.org
Copyright 2013 Air & Waste Management Association
R T TR AT CA
as Ga eG usse ou ho nh en ee G Grre ing lorrin aiilo Ta T
june 2013 em 27
