If you build a power plant but don’t connect it to the grid, the EPA now says certain federal pollution rules don’t apply to you. That’s the gist of a memo issued on July 16 by EPA Assistant Administrator Aaron Szabo, and it could quietly reshape how data centers, and potentially crypto mining operations, get their electricity.

The clarification centers on what the agency calls “islanded” power generation facilities. These are self-contained plants that serve a single private consumer, like a data center, without ever touching the public utility grid. According to the EPA, these facilities fall outside the scope of the Acid Rain Program under the Clean Air Act.

What the Acid Rain Program actually does

The Acid Rain Program, or ARP, has been around since the 1990 amendments to the Clean Air Act. It caps emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) from large electric generating units connected to the grid.

The EPA’s legal reasoning here is surprisingly straightforward. The ARP’s definitions, drawn from the 1990 DOE Form 860, specifically cover generators that sell electricity “primarily for use by the public.” If your power plant exists solely to feed a single private operation and never sends a watt to the grid, you’re technically not selling to the public.

The memo was prompted by inquiries from multiple companies and state regulators. One concrete example: a proposed 500 MW natural gas facility designed exclusively to power a single data center. For context, 500 MW is enough to power roughly 375,000 homes. But because this plant would operate as a closed loop, serving only its attached data center, the EPA says the ARP doesn’t apply.

The plant still needs to comply with other Clean Air Act provisions and state-level regulations. But removing ARP compliance from the equation meaningfully reduces the regulatory burden, cost, and timeline for building dedicated power infrastructure.

Why this matters for AI and crypto

The EPA under Administrator Lee Zeldin has been actively working to streamline air permitting for data centers. In December 2025, the EPA launched a Clean Air Act resource hub specifically for data centers. Then in May 2026, the agency proposed allowing partial construction of facilities before full permitting is complete. The latest ARP clarification is another domino in that sequence.

No national standards for data center operations have been enacted. Instead, oversight has largely shifted to state authorities, creating a patchwork of rules that varies dramatically depending on where you build.

While reporting on this memo has focused almost entirely on AI data centers, the logic applies equally to any islanded power facility serving a private consumer. That includes Bitcoin mining operations, which have increasingly sought dedicated power sources. Large-scale crypto mining operations already consume enormous amounts of electricity. Marathon Digital, Riot Platforms, and other publicly traded miners have spent years negotiating power agreements and, in some cases, building or co-locating with dedicated generation assets.

What investors should watch

Directly, companies that build, own, or operate data center infrastructure stand to benefit from faster permitting and lower compliance costs. If you can break ground on a 500 MW gas plant without navigating ARP requirements, your project timeline compresses and your capital costs drop.

The risk side of the ledger is equally important. State regulators could impose their own emissions caps that effectively replicate ARP requirements. Environmental litigation is virtually guaranteed, and a memo clarifying existing statutory definitions is a much easier target than a formal rulemaking with public comment periods.