Environmental review is a process that requires government agencies to analyze the potential effects of a proposed action on the environment before approving it. When it applies, it is one of the strongest tools available to communities seeking to understand and influence how a data center will affect their neighborhood. When it does not apply — which is often — communities must rely on other mechanisms.
This article explains the federal environmental review framework and its limits, the state-level laws that sometimes provide stronger protections, the concept of environmental justice and its relevance to data center siting, and how residents can participate when review is triggered.
The National Environmental Policy Act: What It Requires and When It Applies
The National Environmental Policy Act (NEPA), enacted in 1970, requires federal agencies to assess the environmental effects of their proposed actions before making decisions. The assessment takes one of three forms: a categorical exclusion (for actions with no significant effects), an environmental assessment (EA), or a full environmental impact statement (EIS) for major actions significantly affecting the environment.
The key word is “federal.” NEPA applies only when there is a federal nexus — when the project involves a federal agency action, federal land, federal permits, or federal funding. A purely private data center project on privately owned land, funded with private capital, requiring no federal permits, does not trigger NEPA review. This is the situation for the vast majority of data center projects across the United States.
Federal nexuses that could trigger NEPA for a data center include: construction on or adjacent to federal land; permits issued by the U.S. Army Corps of Engineers for wetland impacts; Federal Aviation Administration approval for structures near airports; federal funding provided directly or as part of an economic development package; and some telecommunications infrastructure approvals. In each of these cases, the federal agency with jurisdiction would be responsible for conducting or overseeing the NEPA review.
When NEPA does apply and a full EIS is required, the law mandates public involvement at multiple stages: a scoping period (in which the public helps define what issues the EIS should address), a public comment period on the draft EIS, and agency responses to substantive comments before a final decision is made. The record of public comments and agency responses is part of the legal basis for any subsequent challenge.
The Trump Administration’s July 2025 executive order on accelerating data center permitting pushed in the opposite direction — directing agencies to establish new categorical exclusions for data center construction activities and establishing a presumption that projects receiving less than 50 percent of their funding from federal sources do not constitute “major federal actions” under NEPA. That presumption, if implemented as written, would further narrow the range of data center projects subject to federal environmental review, even those with some federal involvement.
State Environmental Review Laws
Because NEPA rarely applies to private data center projects, the more relevant question for most communities is whether their state has an equivalent environmental review law. State laws vary enormously in their scope, their standards, and the degree to which they give the public meaningful access.
California Environmental Quality Act (CEQA). CEQA is the strongest and most neighbor-accessible state environmental review law in the country. It applies to discretionary approvals by state and local agencies — meaning that any time a government body must exercise judgment in deciding whether to approve a project (rather than issuing a ministerial permit), CEQA review may be triggered. An EIR under CEQA must analyze noise, water use, air quality, traffic, greenhouse gas emissions, biological resources, and other relevant impacts. The public has the right to comment on a draft EIR, and lead agencies must respond substantively to comments. Inadequate responses can be challenged in court.
For data centers, California’s CEQA treatment has been shifting. The state has historically allowed local agencies to use categorical exemptions — standard determinations that certain classes of projects have no significant environmental effect — for some data center approvals. A 2026 California Senate bill, SB 887, would prohibit the use of categorical exemptions for data center projects, requiring every such project to undergo at minimum an initial study and likely a full EIR. A related bill, AB 2170, would impose significant new public participation requirements — including 60-day notice, translated documents, and expanded public hearings — for industrial facilities, including data centers, located within half a mile of communities with the highest pollution burden scores. These bills were pending as of mid-2026.
A California data center case from early 2026 illustrates what inadequate review looks like: State Senator Steve Padilla issued a statement questioning why Imperial County approved a data center project under a CEQA exemption, asking under what grounds the county determined the facility was exempt given the growing concerns about data center energy and water demands.
New York State Environmental Quality Review Act (SEQRA). New York’s SEQRA covers a broad range of actions by state and local agencies. It follows a similar structure to CEQA — lead agency designation, environmental assessment form, potential EIS — but has historically been less frequently used as a community tool than California’s law, in part because of differences in the litigation landscape.
Washington State Environmental Policy Act (SEPA). Washington’s SEPA applies to most significant governmental actions, including many local permits. Like CEQA, it requires an environmental checklist and, for projects with potentially significant impacts, a full environmental impact statement. Data center projects in Washington that require discretionary local approval may trigger SEPA review.
States with minimal or no equivalent. Many states — including Virginia, Texas, Arizona, Georgia, and most of the South — have no state environmental review law comparable to CEQA, SEQRA, or SEPA. In these states, environmental review of data center projects is limited to whatever federal nexus exists (usually none) and whatever specific permits may be required under state air or water quality laws. Those permits may include public comment opportunities, but they are narrower in scope than a full environmental review.
What an Environmental Assessment Covers
When environmental review is triggered, the assessment or impact statement examines a defined set of topics. For data centers, the most relevant include:
Noise. An EIR or EIS will typically include a noise study comparing projected sound levels from facility operations against applicable standards at nearby sensitive receptors (homes, schools, care facilities). This study can be challenged by commenters if the methodology is flawed — for example, if it fails to account for low-frequency noise that decibel meters do not adequately capture.
Water use. Data centers that use evaporative cooling can consume millions of gallons of water annually. An environmental review should analyze the source of that water, the impact on local water supplies, and alternatives (such as air cooling or closed-loop systems). In drought-affected regions, water use analysis is particularly significant.
Air quality. Backup diesel generators are significant sources of particulate matter and nitrogen oxides. Diesel generators at data centers may operate for hundreds of hours annually during grid testing and actual outages. An EIR should analyze the cumulative air quality impacts, particularly for communities already near or above air quality thresholds.
Traffic. Construction traffic impacts, including truck routes through residential streets and cumulative effects on intersections, should be analyzed and disclosed.
Grid impacts. A full analysis should address how the facility’s electrical demand will be met, whether new transmission infrastructure is required, and what the reliability implications are for existing customers.
Cumulative impacts. Environmental review requires analysis of cumulative impacts — the combined effect of the proposed project plus existing and reasonably foreseeable future development. In regions with high data center density, this is particularly important: the impact of any single facility may be acceptable in isolation but unacceptable in combination with neighboring facilities.
How to Find Out If Environmental Review Applies
California: The lead agency (usually a city or county) will post a Notice of Intent to Adopt a Negative Declaration, Mitigated Negative Declaration, or a Notice of Preparation for an EIR in the State Clearinghouse and on the agency’s website. Sign up for notifications from your city or county planning department and monitor the California State Clearinghouse at ceqanet.opr.ca.gov.
New York: SEQRA notices are published in the Environmental Notice Bulletin. Lead agencies are required to provide notice to adjacent property owners and interested agencies.
Washington: SEPA documents are filed with the Department of Ecology and published in a threshold determination notice that is available through local planning departments.
All states: Contact your local planning department and ask whether the proposed project is subject to environmental review under state law, what agency is serving as lead agency, and when the public comment period opens. These are questions staff are required to answer.
How to Participate Effectively
When environmental review is triggered, the public comment process is the primary vehicle for community input. Effective comments share several characteristics:
Raise specific, substantive issues. Comments that identify specific deficiencies in the analysis — missing data, flawed methodology, underestimated impacts — carry more legal weight than general expressions of concern. If a noise study does not measure low-frequency components, say so and explain why that matters. If a water analysis relies on outdated groundwater data, identify the more current source.
Propose specific alternatives or mitigation measures. Environmental review requires agencies to consider a reasonable range of alternatives and to adopt feasible mitigation. Comments that propose specific alternatives (a different site, a design that uses air cooling instead of evaporative cooling, a smaller facility footprint) or specific mitigation measures (sound barriers, limits on generator testing, truck route restrictions) give the agency something to respond to — and an inadequate response can support a legal challenge.
Submit comments in writing and before the deadline. Oral testimony at a public hearing is part of the record, but written comments are the primary basis for legal challenge. Submit written comments before the close of the public comment period. The deadline is hard — late comments may not be required to receive responses.
Create a coalition of commenters. Agencies receive comments from many sources. Comments from medical professionals about health effects, from acoustical engineers about noise methodology, from hydrology experts about water impacts, from local schools about children’s exposure, and from individual residents about daily lived experience together create a stronger record than any single perspective.
Preserve your legal rights. In California, under CEQA, a party must have submitted comments during the public comment period to have standing to challenge the approval in court. In other states, similar requirements may apply. Know the rules in your jurisdiction.
Environmental Justice: The Framework and Its Limits
Environmental justice, as a legal and policy concept, concerns the disproportionate siting of polluting or hazardous facilities in low-income communities and communities of color. President Clinton’s Executive Order 12898, signed in 1994, directed federal agencies to identify and address disproportionately high and adverse effects on minority and low-income populations from their programs, policies, and activities.
The executive order applies to federal agencies. It does not directly regulate where private data centers locate, and research has shown that it has had limited practical effect even in the federal programs it was designed to address. But the framework is relevant to data center siting in two ways.
First, where a federal nexus exists, federal agencies conducting environmental review are required by the executive order to analyze disproportionate impacts on environmental justice communities. If a data center involves any federal action — federal permits, federal land, or federal funding — and is proposed in a community that qualifies as an environmental justice community under the EPA’s screening tools (EJScreen, available at ejscreen.epa.gov), that analysis is required and can be challenged if it is inadequate.
Second, many states have adopted their own environmental justice requirements that apply independently of federal action. California’s SB 1000 requires cities and counties to adopt an environmental justice element in their general plans if they have disadvantaged communities. New York’s Climate Leadership and Community Protection Act includes significant environmental justice provisions. These state requirements may apply to data center approvals in ways that the federal executive order does not.
The broader point is that data centers — like other large industrial facilities — are not randomly distributed across the landscape. They tend to locate where land is relatively cheap, where regulatory environments are permissive, and where political resistance is limited. Those factors often, though not always, correlate with communities that have less political power. When that pattern is visible in a specific case, environmental justice law and policy provide a framework for naming it and, in some jurisdictions, for requiring that it be addressed.
What Has Happened When Review Was Organized
In communities where environmental review has been triggered and residents have organized effective participation, the outcomes include:
In California, organized CEQA challenges to data center projects have produced project modifications, additional mitigation measures, and in some cases delays that gave communities additional time to negotiate. The requirement that lead agencies respond substantively to comments creates accountability that is absent when review is not triggered.
The California SB 887 bill pending in 2026 represents a legislative response to years of data center approvals without meaningful review — a recognition that the pattern of exemptions has left communities without a formal mechanism to analyze and address cumulative impacts. If enacted, it would give California residents much more consistent access to environmental review for data center projects than they have had.
In jurisdictions without strong state environmental review laws, the absence of that mechanism is itself important information. It tells you that the formal review process is not available and that other tools — zoning hearings, noise ordinances, utility commission proceedings, legislative advocacy — must carry more of the weight. Those tools are covered in other articles on this site: zoning leverage, noise ordinances, and tax abatements, where public hearing processes offer at least partial substitutes for the environmental review that the state does not require.