Environmental Justice and Zoning Reform

Zoning is a legal tool used for many aspects of planning implementation. It empowers a jurisdiction's administrators to regulate land use and development as a way of implementing adopted policies. However, since its inception, zoning has faced criticism for disparately impacting certain communities of people when shaping cities. This includes discriminatory effects on historically disenfranchised populations, such as low-income households and communities of color.

There is growing acknowledgment within the planning profession that planners have a responsibility to identify and eliminate historical patterns of inequity caused by planning decisions and to mitigate the effects of those patterns still felt in communities today. Increased awareness of equity requires analyzing how existing laws and policies affect different populations. A deeper understanding of the flaws of existing systems allows local governments to implement intentional policies resolving disparities in the way zoning regulations impact vulnerable populations and can lead to a comprehensive rebuilding of those systems.

Many researchers have criticized land use patterns that distribute certain uses known to have harmful environmental effects in ways that disproportionately impact historically disenfranchised groups. As planners nationwide consider zoning reform, an important factor to assess is its role in clustering harmful, high-intensity land uses adjacent to communities of color, low-income neighborhoods, and other underserved populations.

This PAS Report examines the role of zoning ordinances in environmental injustices and presents a diagnostic tool for determining whether zoning might be disproportionately harming vulnerable groups within a jurisdiction. Building on PAS Report 549/550, Fair and Healthy Land Use: Environmental Justice and Planning, it offers a toolbox of potential mitigation actions for zoning codes, their application, and zoning processes; provides examples of zoning reforms in U.S. cities that target environmental justice concerns; and shares additional resources that support zoning reform efforts for environmental justice.

Zoning and Disparate Impact

Conventional use-based zoning separates uses into tiers based on perceived intensity of use. High-intensity land uses are those that generate high negative externalities and therefore have a strong impact on properties around them. The definition of a negative externality has two aspects: (1) the use of one property results in some negative impact on another, and (2) those impacted do not receive any compensation.

High-intensity land uses, such as heavy industry, auto repair, and distribution warehouses, often emit byproducts that affect the air, soil, water, and quality of life for surrounding properties. Owners often cannot contain environmental impacts within their property lines. Adjacent, downwind, or downstream properties are affected. The placement of zoning districts that permit heavy commercial and industrial land uses with known harmful effects on public health near places where people live is therefore a concern. Chapter 3 of this report describes the negative externalities caused by these uses and how the placement of high-intensity land uses can have consequences for the health, safety, and welfare of individuals, families, and communities.

Planners often use zoning as a means of restricting hazardous uses to locations away from where people live, work, and play. Protecting the public justifies conventional use-based zoning as a valid use of the police power. But if some populations are put at risk because of zoning decisions, it defeats this purpose. Cities become liable if they are not providing equal protection to all residents under the law or are creating situations that are disproportionately harmful to some groups versus others.

Disparate impact is an unintentional discriminatory effect by a law on a protected class. Title VII of the 1964 Civil Rights Act prohibits discrimination against individuals or groups of people based on race, color, religion, sex (including gender identity and sexual orientation), and national origin. There are three types of constitutional challenges to ordinances that seem to have disparate impacts: facial challenges, as applied challenges, and due process challenges. Challenging an ordinance "on its face" is a claim that the explicit wording of the code or law is unlawful. Challenging an ordinance "as applied" is a claim of unlawful interpretation or application of zoning by a zoning administrator, commissioner, or official. "Due process" includes the right to be heard and noticed during procedures by which cities enact, amend, and enforce zoning codes. If a challenging party can demonstrate that there are aspects of zoning text, maps, or procedures that marginalize or harm protected groups, the city could be liable.

Substantial evidence shows that residents in some cities are facing environmental inequality due to zoning laws. Chapter 2 of this report documents research on the history of zoning demonstrating that social segregation was among the motives for its widespread establishment. As a result, historically disenfranchised groups, including people of color and low-income households, are often relegated to lower-quality environments with environmental justice consequences. Of particular concern is zoning that disproportionately clusters high-intensity uses in "sacrifice zones" where they predominately affect low-income communities and people of color.

Persistent, statistically significant relationships between income, race, and hazardous zoning present a challenge for city planners to resolve. The ethical imperative is clear, and planners must also understand the legal ramifications. If patterns of environmental disparity and injustice persist in zoning codes, planners must act to mitigate these impacts. Otherwise, cities may be held liable for ongoing disparity. This report highlights the importance of planners analyzing the distributions of high-intensity land uses in their own communities to determine if there is potential for disparate impact through environmental injustice.

The EJ Zoning Disparity Test

Understanding how current land use regulations create the potential for injustice is crucial for resolving it. The widespread assertions and evidence that zoning has potential for disparate impact relating to race and income show that these relationships are a good place to begin. For planners looking to identify and address zoning-related injustice, a diagnostic litmus test is the first step.

The digitalization of zoning maps and availability of open-source statistics software has opened up new methods of evaluating the possibility for disparate impact. Chapter 4 of this PAS Report introduces the Environmental Justice (EJ) Zoning Disparity Test, a simple litmus test that planners can apply in their own communities to evaluate the presence and degree of zoning-based disparate impact and to provide quantitative evidence to support zoning reform.

The EJ Zoning Disparity Test examines how the presence of high-intensity zoning relates to a city's population. It measures the relationship between parcels zoned for high-intensity uses and the socioeconomic characteristics of the census tracts in which they are located to determine whether parcels zoned for high-intensity uses are more likely to occur in census tracts with higher proportions of people of color, lower incomes, or other characteristics of protected or underserved populations. Disproportionate distributions of high-intensity zoning would result in the test showing a higher likelihood of certain socioeconomic populations experiencing the impacts of high-intensity zoning.

The report shares research in which the author applied the test to examine high-intensity zoning distributions in relation to population distributions of low-income households and people of color in 13 major U.S. cities. The outcomes suggest strong correlations between the location of low-income communities, communities of color, and zoning that permits intensive commercial and industrial land uses, showing that zoning currently holds potential for disparate impact in most of those cities analyzed. This points to a need for city planners to examine the relationship between high-intensity zoning and vulnerable communities in their own jurisdictions. Detailed step-by-step guidance to help planners apply the EJ Zoning Disparity Test in their communities is provided in the appendix to this report.

Zoning Reform for Environmental Justice

The principles of equity and justice are considered integral to contemporary planning practice. Evidence of disparity in the distributions of high-intensity, potentially hazardous land uses in relation to vulnerable or historically disenfranchised populations should prompt planning action and remediation steps for the benefit of the city and its constituents. Planners will need tools to improve their city's zoning practices. These include adopting both short- and long-term interventions and recommended practices.

Chapter 5 of this report offers a zoning reform toolkit for practicing planners and administrators to use for identifying the issues with current zoning practice, addressing those concerns directly, and monitoring their zoning in the future for disparate impacts. The toolkit offers three sets of mitigation methods:

Methods that address the spatial application of zoning (the zoning map), which include downzoning industrial land, concentrating high-intensity zoning, buffering high-intensity uses, increasing housing choice, and redeveloping brownfield sites.

Methods that address the language of the zoning code, which include grouping high-intensity uses, revising multifamily housing classifications, strengthening mitigation requirements, using discretionary and overlay zoning, requiring local environmental impact assessments, enacting density clauses, and adopting performance zoning.

Methods that address zoning procedures, which include assessing planning procedures for potential inequities, incorporating advocacy planning principles in practice, increasing the diversity of decision-makers, training decision-makers, clarifying goals and tracking progress, increasing accessible public participation opportunities, and prioritizing code enforcement.

The report also discusses necessary conditions for change, which include political and policy support, dedicated municipal resources, business and development incentives, and state and federal support. These legal, political, and financial preparations will improve the odds for successful zoning reform.

Some cities have begun the work of zoning reform for environmental justice, and planners seeking to address these issues can learn from their efforts. Chapter 6 of this report provides several examples of recent zoning reforms, programs, and successful land use patterns from the United States and internationally to illustrate different implementation strategies for remediating injustice. Collectively, the experiences of these cities provide insight into the practical application of zoning and planning reforms for environmental justice, showcasing both challenges and successes.

Taking on Regulatory Reform

Jurisdictions across the nation have systemically unjust regulatory systems based on historically biased planning goals and reflective of past discrimination. Many low-income households and communities of color suffer the burdens of environmental externalities that exacerbate health and socioeconomic disparities. But, as this PAS Report shows, planners today can use tools such as the EJ Zoning Diagnostic Test to detect the disparate impacts of zoning. And they can address these longstanding disparities by working to reform zoning codes, zoning maps, and regulatory due process and advocating for policies that support more equitable zoning regulations and processes.

Planners have the power to act as advocates for those historically discriminated against and underserved. Those who experience the externalities of hazardous land uses may not know it. The most vulnerable in our communities often lack the resources, time, access, or knowledge to affect local decision-making. Planners must build advocacy into each step of the planning process if they truly seek to preserve the health, safety, and welfare of their publics.

Planning departments and zoning ordinances cannot continue to function as they have for decades. If change is to occur, planners must reconsider their approaches and make amendments. The legal foundation of zoning — protecting the health, safety, and welfare of the general public — means all members of a community are entitled to protection, regardless of their socioeconomic status, ethnicity, housing unit type, or other differentiating factor. This PAS Report calls on planners to identify those who are disproportionately burdened and reform zoning codes and procedures to protect the communities they serve.