Green Infrastructure for Sustainable Landscapes: Three Case Studies

This post is an abstract summary and introduction to the graduate thesis: Green Infrastructure for Sustainable Landscapes: Three Case Studies. The graduate thesis was completed in partial fulfillment of the requirements for the degree of Master of Arts in Urban and Environmental Policy and Planning at Tufts University. 

This thesis was originally published on ProQuest online database and can be browsed on ProQuest Dissertations & Theses @ Tufts University, available to members of the Tufts community and the Tufts Digital Library, openly available to all readers. 

Abstract  

Cities across the United States are struggling to manage their aging infrastructure, which is exacerbated by high-intensity rainfall events and cause sewage overflow, infrastructure damage, erosion, habitat destruction, and high nutrient contamination. Green infrastructure is demonstrating the potential to manage private land parcels that generate a significant source of stormwater pollution. However, the absence of standards and guidelines for green infrastructure is discouraging its implementation. The opportunity to address some of these challenges can be addressed through the SITES Rating System (SITES), which has guidelines for holistic green design to improve stormwater management. This thesis asks the following questions: “what is green infrastructure and how does it effectively manage stormwater?” and “what is SITES and how does it promote the adoption of green infrastructure?” A case study methodology is used to analyze three SITES-certified projects that implement green infrastructure measures for stormwater management, site restoration, and remediation. The replication of green infrastructure measures across three SITES certified projects provides evidence-based evaluation including quantitative and qualitative evidence for stormwater management, treatment and filtration of stormwater pollutants, community benefits such as outdoor enjoyment, and ecosystem services such as the provision of wildlife habitat and flood regulation. Summary of findings address external validity, reliability, construct validity, and internal validity of green infrastructure measures in SITES certified projects, with future research opportunities to address common barriers, policy implications, and additional tools for integration with SITES.  

Introduction 

Cities across the United States are struggling to manage their aging infrastructure. This is exacerbated by high-intensity rainfall events, which cause sewage overflow, infrastructure damage, erosion, habitat destruction, and high nutrient contamination.^1,2 Stormwater runoff poses risk to residents, businesses, endangering public health and environmental quality.³ The Clean Water Act, the primary federal law that regulates stormwater in the U.S., aims to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.⁴ The National Pollution Discharge Elimination System (NPDES) under this law is failing to address the physical and biological integrity of the Nation’s waters.^5,6 The NPDES permit relies on cities to manage their aging Municipal Storm Sewer System (MS4) through point sources, which are defined as discernable, confined, and secrete grey infrastructure conveyance such as pipes, ditches, and tunnels.⁷ The Clean Water Act does not provide legal authority to manage private land parcels, ignoring the significant source of stormwater pollution generated through non-point sources.⁸ Non-point source pollution is defined as pollution that is caused by overland runoff such as rain which picks up and carries pollutants and deposits them into lakes, water, groundwater, and wetlands.⁹ The most recent National Water Quality Inventory Report to the U.S. Congress lists urban-related stormwater runoff as a leading probable pollutant source.¹⁰ High-intensity rainfall events and flooding are overwhelming the traditional grey infrastructure approach to control stormwater flow, carrying pollutants such as phosphorus, nitrogen, pathogens, and pesticides into our larger watersheds.¹¹ This is causing many large municipalities to be out of compliance with the Environmental Protection Agency’s Clean Water Act.¹²

Another provision under the Clean Water Act is the Total Maximum Daily Load. The Total Maximum Daily Load requires a plan for the restoration of impaired waters that exceed the maximum number of pollutants a waterbody can receive.¹³ Waterbodies are failing to meet their water quality standards, as non-point sources continue to be overlooked and play a major contribution in polluting impaired waters. A major problem in watershed management has been identifying the best techniques to treat maximum stormwater runoff.¹⁴ This issue creates a compelling need for a combination of solutions that treat stormwater runoff pollutants at both non-point and point sources. Long-term solutions should work to improve all factors that contribute to the degradation of water quality and leverage services of green infrastructure.¹⁵

In early 2019, the U.S Congress approved the Water Infrastructure Improvement Act, which amended the Clean Water Act to allow municipalities to develop a plan which may include the implementation of green infrastructure.¹⁶ Additionally, the Municipal Separate Storm Sewer System (MS4) permits are increasing green infrastructure provisions in their permit.¹⁷ Green infrastructure design can be applied to several challenges such as sewage overflow, infrastructure damage, erosion, habitat destruction, and high nutrient contamination.¹⁸ The enactment of the Water Infrastructure Improvement Act is a significant step forward in influencing cities to implement green infrastructure, but not the only limitation in adopting the practice.

Funding sources for stormwater management are currently limited to grey infrastructure, eliminating the ability to holistically consider non-point source discharges and discouraging the use of funds on private properties.^19,20 Resource and cognitive barriers such as lack of funding, lack of awareness and knowledge, as well as fear of new strategies create further reluctance in adopting green infrastructure practices.²¹ Furthermore, ecosystem values lack proper tools to generate revenue, discouraging private investment.²² Though there are many cost and ecological benefits to green infrastructure strategies, they are undervalued due to limitations of use and absence in market value.²³ Fear, attitudes, and perceptions also create reluctance in adopting new sustainable practices.²⁴ The application of green infrastructure requires more evidence-based evaluations, currently underway in the United States.²⁵ This thesis asks the following questions: “what is green infrastructure and how does it effectively manage stormwater?” and “what is the SITES Rating System (SITES) and how does it promote the adoption of green infrastructure?”²⁶ Precedent cases of adopting and adapting the SITES at the federal, state, and local government levels have demonstrated the success of green infrastructure integration in landscape governance. Yin’s case study methodology is used to analyze three SITES-certified projects that implement green infrastructure measures for stormwater management, site restoration, and remediation.²⁷ This analysis addresses the “how” and “why” phenomenon of green infrastructure implementation. The replication of green infrastructure measures in SITES certified projects provides construct validity through performance indicators such as stormwater treatment and provision of wildlife habitat. Summary of findings address external validity, reliability, construct validity, and internal validity of green infrastructure measures, with future research opportunities to address common barriers, policy implications, and additional tools for integration with SITES.

¹ Todd K. BenDor et al., “Ecosystem Services and US Stormwater Planning: An Approach for Improving Urban Stormwater Decisions,” Environmental Science & Policy 88 (October 2018): 92–103, https://doi.org/10.1016/j.envsci.2018.06.006.

² Note: parts of the introduction and literature review in this thesis were previously published in the American Society of Landscape Architects National Blog, The Field. This blog post was inspired a literature review for the Foundations of Public Policy and Planning class at Tufts University, where articles and publications were reviewed to address the topic of stormwater runoff and sustainable solutions for this thesis. Aqsa Butt, “Strategies in Implementing Green Infrastructure Design,” The Field, April 9, 2019, https://thefield.asla.org/tag/aqsa-butt/.

³ BenDor et al., “Ecosystem Services and US Stormwater Planning.”

⁴ Krishna P. Dhakal and Lizette R. Chevalier, “Managing Urban Stormwater for Urban Sustainability: Barriers and Policy Solutions for Green Infrastructure Application,” Journal of Environmental Management 203 (December 1, 2017): 171–81.

⁵ Krishna P. Dhakal and Lizette R. Chevalier, “Managing Urban Stormwater for Urban Sustainability: Barriers and Policy Solutions for Green Infrastructure Application,” Journal of Environmental Management 203 (December 1, 2017): 171–81, https://doi.org/10.1016/j.jenvman.2017.07.065.

⁶ “Stormwater Discharges from Municipal Sources,” Overviews and Factsheets, US EPA, November 2, 2015, https://www.epa.gov/npdes/stormwater-discharges-municipal-sources.

⁷ US EPA, “Basic Information about Nonpoint Source (NPS) Pollution,” Overviews and Factsheets, US EPA, September 15, 2015, https://www.epa.gov/nps/basic-information-about-nonpoint-source-nps-pollution.

⁸ Dhakal and Chevalier, “Managing Urban Stormwater for Urban Sustainability.”

⁹ US EPA, “Polluted Runoff: Nonpoint Source (NPS) Pollution,” Collections and Lists, US EPA, February 20, 2015, https://www.epa.gov/nps.

¹⁰ US EPA, “National Water Quality Inventory Report to Congress,” Data and Tools, September 17, 2015, https://www.epa.gov/waterdata/national-water-quality-inventory-report-congress.

¹¹ “Introduction to the Clean Water Act,” US EPA, accessed November 7, 2018, https://cfpub.epa.gov/watertrain/moduleFrame.cfm?parent_object_id=2165.

¹² Timothy T. Eaton, “Approach and Case-Study of Green Infrastructure Screening Analysis for Urban Stormwater Control,” Journal of Environmental Management 209 (March 1, 2018): 495–504, https://doi.org/10.1016/j.jenvman.2017.12.068.

¹³ “Introduction to the Clean Water Act.”

¹⁴ Edward A. Cook, “Green Site Design: Strategies for Storm Water Management,” Journal of Green Building 2, no. 4 (FAL 2007): 46–56, https://doi.org/10.3992/jgb.2.4.46.

¹⁵ Carli D. Flynn and Cliff I. Davidson, “Adapting the Social-Ecological System Framework for Urban Stormwater Management: The Case of Green Infrastructure Adoption,” Ecology and Society 21, no. 4 (2016), http://www.jstor.org/stable/26270003.

¹⁶ Bob Gibbs, “H.R.7279 – 115th Congress (2017-2018): Water Infrastructure Improvement Act,” webpage, January 14, 2019, 2017/2018, https://www.congress.gov/bill/115th-congress/house-bill/7279.

¹⁷ OW US EPA, “Integrating Green Infrastructure into Federal Regulatory Programs,” Collections and Lists, US EPA, October 2, 2015, https://www.epa.gov/green-infrastructure/integrating-green-infrastructure-federal-regulatory-programs.

¹⁸ BenDor et al., “Ecosystem Services and US Stormwater Planning.”

¹⁹ Dhakal and Chevalier, “Managing Urban Stormwater for Urban Sustainability.”

²⁰ BenDor et al., “Ecosystem Services and US Stormwater Planning.”

²¹ Dhakal and Chevalier, “Managing Urban Stormwater for Urban Sustainability.”

²² Dhakal and Chevalier.

²³ Dhakal and Chevalier.

²⁴ Dhakal and Chevalier.

²⁵ BenDor et al., “Ecosystem Services and US Stormwater Planning.”

²⁶ Note: The SITES program provides an educational path for professionals to attain SITES accreditation, which includes the appellation “SITES AP”. The SITES accreditation provides landscape professionals with the opportunity to demonstrate their knowledge, expertise, and commitment to the profession. I achieved the SITES AP designation in July 2018 and since then it has become a major part of my professional identity. While my own professional affiliation with SITES could introduce bias into this research, I have adopted a rigorous case study methodology to mitigate biases to attempt to present an objective analysis of the SITES program. “SITES AP | SITES,” The Sustainable SITES Initiative, accessed July 18, 2021, https://www.sustainablesites.org/sites-ap.

²⁷ Robert K. Yin, Case Study and Research and Applications Design and Methods, 6th Edition (Sage Publications Inc., 2018).