Choosing Perpetual Management: Urban Runoff and the Origins of its Mitigation

Editor’s note: This is the fifth post in our theme for January 2022, Urban Environmentalism. Additional entries can be seen at the end of this article.

By Amanda K. Philips de Lucas

Regulating Urban Runoff 

Presently, cities across the United States battle a microscopic foe. The particulate matter of urban existence, during wet weather events, travel over impervious surfaces and into storm sewers. Some of these sewers are combined, meaning stormwater runoff mixes with household effluent before being transported to a treatment center. Other city sewers are separated. In these cases, stormwater travels through the pipe under our feet, funneled by gravity sewers, to receiving bodies of water. This flow of nutrients, nitrogen and phosphorus, toxics, such as lead, and other solids are known as nonpoint source pollutants.

While the pollutant potential of stormwater runoff poses a risk to water quality in most developed areas, the issue is particularly acute for cities. Urbanization in many US contexts has replaced permeable surfaces, like soils, with concrete and asphalt. Impermeable surfaces provide the perfect transport mechanism for polluting nutrients during a wet weather event. Indeed, nutrient loading, when too many nutrients enter a waterbody, can contaminate groundwater, damage fishing economies, or render drinking water unpotable (as was the case in Toledo in 2014).[1]

Beginning in the 1990s the Environmental Protection Agency (EPA), through a mechanism called a Municipal Separated Storm Sewer Permit (MS4), began to regulate stormwater discharges containing nonpoint source pollutants. MS4 permits placed cities on ‘nutrient diets’ by creating monitoring programs and encouraging remediation efforts to reduce water pollution caused by stormwater runoff. Yet, it took decades from the initial passage of the Clean Water Act (CWA) for nonpoint sources of water pollution to be treated as a legitimate hazard.

Increasingly, cities under MS4 permits turn to green stormwater infrastructure (GSI) as a mechanism to address water quality concerns.[2] GSI, such as bioswales, rain gardens, or curb bump-outs, captures stormwater water and absorbs it into permeable soils or plant material. These installations prevent the transportation of nutrients to receiving bodies of water. While green infrastructure are often lauded by environmental advocates for providing ecosystem services to cities, these landscape features perpetually manage, rather than mitigate, nonpoint sources.[3]  Installing GSI is a technological choice by cities, endorsed by the EPA, that reflects a long history of federal inaction to consider urban runoff as a pollutant and effectively curtail its impact.[4] As cities increasingly seek to implement nature-based-solutions or sustainable infrastructures, this history draws attention to the importance of understanding the values and imperatives shaping our current technological choices.

The Emerging Problem of Nonpoint Sources

In 1972 amendments to the 1948 Federal Water Pollution Control Act were passed, overriding a presidential veto by Richard Nixon. This legislation, which would eventually be renamed the “Clean Water Act” in 1977, aimed “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.” Initially, the CWA only addressed pollution stemming from point sources. Point source pollution consists of effluent, toxic materials, or contaminants dumped from an identifiable outfall location. 

The sole regulation of point sources did not mean that nonpoint sources were unknown as potential pollutants. In 1969 the American Public Works Association (APWA), contracted by Federal Water Pollution Control Administration, released a report titled “Water Pollution Aspects of Urban Runoff.” This report identifies sources within urban areas such as trash, leaf litter, and other chemicals as contributors to the pollution of urban stormwater runoff.[5]

Even earlier, in 1964, the U.S. Department of Health, Education, and Welfare released a report on the impact of combined stormwater overflows and pollution.[6] The report’s authors acknowledged that urban runoff frequently contains contaminants from nonpoint sources, “stormwater alone was determined to carry significant amounts of pollutional load.”[7] Indeed, the APWA report cited eight previous studies demonstrating the “water pollution potential” of urban stormwater.[8] 

Eventually, federal programs sponsored by the EPA began to collect data investigating the impacts of nonpoint source pollution caused by urban runoff.[9] The Clean Lakes Program (CLP), which ran from 1976-1979, provided matching federal funds to cities, municipalities, and others interested in protecting or restoring water quality within lakes. The CLP encouraged participants to implement different management practices and technological solutions to reverse the effects of nutrient accumulation in lakes, also known as eutrophication.[10]

Yet, as of the 1977 amendment to the CWA, regulation of nonpoint sources extended only to agricultural runoff. EPA documentation states that uncertainties persisted “as to the true significance of urban runoff as a contributor to receiving water quality problems.”[11] In response to the apparent lack of knowledge linking stormwater runoff to water pollution, the EPA developed the National Urban Runoff Program (NURP), which ran from 1979-1983. This program aimed to understand the environmental problems stemming from contaminants in stormwater runoff faced by various regions around the country. Additionally, the EPA provided technical assistance to projects funded by the program.[12]

Finally, in 1987 Congress amended the CWA to include Section 319, which created the framework for states to address nonpoint source runoff with federal support.[13] Section 319 provided support in three areas; development, adoption, and implementation of nonpoint source management programs. In total, it took 15 years from the original overhaul of the CWA to acknowledge that nonpoint sources of pollution from urban runoff contributed to degraded water quality. 

The EPA places this lack of congressional action on the overall cost associated with recognizing nonpoint sources of pollution. The agency wrote in a 1983 report that “the unknowns were so great and certain control cost estimates were so high that the Clean Water Act of 1977 deleted Federal funding for the treatment of separate stormwater discharges.”[14] On the surface, this assessment describes congressional action in the face of uncertain science. Yet, the statement also draws attention to the massive capital investment required just upon the mere acknowledgment of urban runoff as nonpoint source pollution. In some estimates, costs for solutions, such as rainwater treatment facilities, were projected at over one billion dollars.[15]

It is not surprising then that the NURP final report and the creation of the 319 funds emphasized developing, implementing, and supporting “Best Management Practices” (BMP) rather than utilizing technological controls.[16] Proposed solutions to improve stormwater quality were hybrid mixtures of site-specific installations, such as grass swales or detention ponds, and public works interventions, like regular street sweeping.[17] Indeed, when the EPA developed rules for separated stormwater, they declared that technological or “end of pipe” treatment solutions were not appropriate for the discharge of runoff.[18]

By deferring to management practices for nonpoint sources the CWA effectively ensured that mitigating the impacts of urban runoff will always be understood as a risk to be managed in perpetuity. This management is formalized through the MS4 program, which requires cities to develop comprehensive plans to reduce polluted separated sewer discharges. Cities must develop regulations to prevent runoff at construction sites, detect illegal discharges, and conduct public awareness campaigns to encourage behavioral change. The EPA even provides a toolbox of logos, mascots, and slogans that cities can use to “be the solution to runoff pollution.”[19]

A storm sewer cover that incorporates the city seal in Jacksonville, Florida. Carol M. Highsmith, 2020, Prints and Photographs Division, Library of Congress.

From Best Management Practices to Green Infrastructure

The recommendations in NURP’s final reports set the stage for the contemporary era of stormwater management using GSI or landscaped facilities. This choice began to take hold in state-wide initiatives and federal permitting requirements aimed to achieve environmental restoration, green space preservation, and the mitigation of damage wrought by non-point source pollution. Stormwater runoff, specifically runoff from urban areas, struggled for recognition as a problem due to its persistence and dispersion in the environment. In this case, the institutional exclusion of urban runoff demonstrates choices made to neglect not only environmental pollutants but the geographies most impacted by this problem, cities.

Cities are increasingly turning to GSI as a technology that not only improves water quality but provides a suite of other services and benefits to residents. The common assumption amongst city planners, engineers, and architects, is that restoring the environment will enhance the quality of lives.[20] It is also fortunate that building landscaped detention facilities brings in federal grant money and checks the boxes on MS4 permitting requirements. While GSI can improve water quality, frequently the nutrient reduction benefit they provide is fairly small. Regardless of actual function, in the face of climate change and ecological degradation, it’s worth asking whether the technical fixes that mitigate risk in perpetuity are the ones best suited for the wickedly complex task at hand. 

Stormwater management programs rarely consider the structural changes that might curtail nonpoint source pollutants for good. Eliminating vehicular traffic in urban areas would lessen airborne and surface accumulating sediments. Significantly reducing impermeable surfaces through road removal could also make a dent in nutrient loads. Instead, permit holders are perpetual bean counters, hoping that their latest pet waste removal campaign or the recently installed rain garden will finally improve water quality.

Similarly, green stormwater infrastructure is a solution to a problem that manages, rather than solves, an environmental hazard. Eliminating non-point source pollutants from urban runoff may be an impossibility at this current moment. But, other solutions beyond landscaped management are rarely on the table. The policy history of managing urban runoff demonstrates that presently cities are significantly curtailed when addressing water pollution. If we want to repair our urban environments, policymakers ought to reopen the question of what technologies we can or should use to prevent water pollution. Now is the time to imagine big solutions, ones less married to the duel ideology of cost reduction and perpetual management.  

Urban Environmentalism (January 2022)


Amanda K. Phillips de Lucas received her PhD in Science and Technology Studies from Virginia Tech in 2018. Her dissertation examined the history of highway building and resistance in Baltimore, Maryland. Her research looks at the history of infrastructure, environmental policy, and social movements. Most recently, she created Governing Greenan experiential toolkit that invites you to explore the social processes shaping environmental projects in cities. 

Featured image (at top): Rain dampens the wares, at least those outside, at the Dixieland Antique Flea Market in Waterford, Michigan. Carol M. Highsmith, 2019, Prints and Photographs Division, Library of Congress.


[1] Clean Water Action, “Harmful Algal Outbreaks and Drinking Water,” https://www.cleanwateraction.org/features/harmful-algal-outbreaks-and-drinking-water.

[2] U. S. Environmental Protection Agency (EPA), “Stormwater Discharges from Municipal Sources,” https://www.epa.gov/npdes/stormwater-discharges-municipal-sources.

[3] Konstantinos Tzoulas, et al., “Promoting ecosystem and human health in urban areas using Green Infrastructure: A literature review,” Landscape and Urban Planning, 81 (2007), http://ggi.dcp.ufl.edu/_library/reference/Promoting%20ecosystem.pdf.

[4] EPA, “Green Infrastructure,” https://www.epa.gov/green-infrastructure.

[5] U. S.Department of the Interior (DOI), “Water Pollution Aspects of Urban Runoff,” (1969).

[6] U.S. Department of Health, Education, and Welfare, “A Preliminary Appraisal: Pollutional Effects of Stormwater and Overflows from Combined Sewer Systems,” (1964).

[7] U.S. Department of Health, Education, and Welfare, “A Preliminary Appraisal,” v.

[8] DOI, “Water Pollution Aspects of Urban Runoff,” 22.

[9] EPA, “Economic Benefits of the Clean Lakes Program” (1980); EPA, “Preliminary Results of the National Urban Runoff Program – Volume II – Appendices” (1982).

[10] EPA, “Your Lake – And the Clean Lakes Program” (1980), 2-3.

[11] EPA, “Results of the Nationwide Urban Runoff Program” (1983), iii.

[12] EPA, “The Hidden Dangers of Urban Stormwater” (1977), 9.

[13] EPA, “Nonpoint Source Control Program” (1983).

[14] EPA, “Final Report of the National Urban Runoff Program” (1983), 1-1-1–2.

[15] EPA, “The Hidden Dangers of Urban Stormwater” (1977), 9.

[16] EPA, “Final Report of the National Urban Runoff Program” (1983), 2–6.

[17] EPA, “Final Report of the National Urban Runoff Program,” 9-13-9–14. Whether street sweeping is useful best management practice is widely debated. The practice was strongly encouraged by the American Public Works Association in Water Pollution Aspects of Urban Runoff. In the NURP Final report, the writers were unconvinced of the efficacy of this practice. As of 2019 street sweeping is an approved alternative Best Management Practice for regions needing to reduce nonpoint source pollution under the Chesapeake Bay Agreement. 

[18] EPA, “National Pollutant Discharge Elimination System Permit Application Regulations for Storm Water Discharges; Final Rule, 48038” (1990).

[19] EPA, “Logos, Slogans, and Mascots,” https://cfpub.epa.gov/npstbx/Logos.cfm.

[20] Amanda Phillips de Lucas, “Gifting a White Elephant, In the Form of Green Infrastructure,” (2020), https://www.thenatureofcities.com/2020/08/18/gifting-a-white-elephant-in-the-form-of-green-infrastructure/.

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