Page-verified permit transcription

CyrusOne Sterling IX/X/XI

Loudoun County, Virginia

QA status VerifiedRelease dated July 29, 2026

EVIDENCE NOTE

What the public record says

A manually verified transcription of equipment groups and permit limits stated in Virginia DEQ permit 74173-6, with one-based PDF page citations. Permitted terms do not establish actual operation or emissions.

Primary sourceVirginia DEQ permit document

Virginia Department of Environmental Quality

Open original source ↗

Summary fields cite p. 3 ↗, p. 4 ↗.

What this record does not establish

The source confirms the document and its stated fields. This profile does not infer actual emissions, compliance history, operating status, facility capacity or environmental impact where those facts are not established by the cited document.

How to read the status

Issued means the agency granted the permit subject to its conditions. It does not mean every permitted unit is operating, that maximum permitted emissions occur, or that later amendments do not exist.

VERIFIED PERMIT TERMS

Equipment and limits,
kept separate from actual use.

This is a conservative transcription of reviewed permit sections, not an exhaustive legal digest. Page numbers refer to the one-based position in the linked PDF. Blank values are not zero.

Permitted equipment

9 document-defined equipment groups. Counts and per-unit ratings are transcribed; combined capacity is not calculated.

Reference	Equipment / model	Count / rating	Fuel / controls	Stated operating field	Source
`Engine Group 3C`	non-emergency diesel engine-generator setCummins or MTU · QSK60-G19 or 16V4000G84S	29 units2250 kW each	dieselSCR+cDPF	See operating-scope table—	p. 6 ↗Permit allows manufacturer/model alternatives.
`Engine Group 4`	non-emergency diesel engine-generator setCummins or MTU · QSK60-G19 or 16V4000G84S	19 units2250 kW each	dieselSCR+cDPF	See operating-scope table—	p. 6 ↗Permit allows manufacturer/model alternatives.
`Engine Group 5 / NVA11_House`	emergency diesel engine-generator setCummins · QSK38-G17 / C1250DE	1 units1250 kW each	diesel—	See operating-scope table—	p. 6 ↗
`Engine Group 1`	emergency diesel engine-generator setMTU · 16V4000G84S / 16V4000 DS2250	16 units2250 kW each	diesel—	See operating-scope table—	p. 7 ↗
`House Gen / H-GEN-1A`	emergency diesel engine-generator setMTU · 16V4000G74S / 16V4000 DS2000	1 units2000 kW each	diesel—	See operating-scope table—	p. 7 ↗
`Engine Group 2A`	emergency diesel engine-generator setCummins · QSK60-G19 / DQKAN	2 units2250 kW each	diesel—	See operating-scope table—	p. 7 ↗
`Engine Group 2B`	emergency diesel engine-generator setCummins · QSK60-G19 / DQKAN	9 units2250 kW each	diesel—	See operating-scope table—	p. 7 ↗
`Engine Group 3A`	emergency diesel engine-generator setCaterpillar · 3516C	1 units2500 kW each	diesel—	See operating-scope table—	p. 7 ↗
`Engine Group 3B`	emergency diesel engine-generator setCummins · QSK60-G19 / DQKAN	4 units2250 kW each	diesel—	See operating-scope table—	p. 7 ↗

Operating scope

Authorized hours, time windows or an explicit finding that no numeric annual-hour cap was located in the reviewed sections.

Reference	Limit	Basis	Source

Permitted emission limits

2 pollutant, unit-group and limit rows. These are permit terms, not measured or actual emissions.

Inspect 2 transcribed limit rows

Reference	Pollutant	Limit	Basis / scope	Source
`Engine Groups 3C and 4`	NOx as NO2controlled	3.53 lb/hrhourly; Cummins QSK60-G19	per unit—	p. 16 ↗
`Engine Groups 3C and 4`	NOx as NO2uncontrolled	42.36 lb/hrhourly; Cummins QSK60-G19	per unit—	p. 16 ↗

DOCUMENT HISTORY

What this document says it changes

permit amendment

Explicitly supersedes the document dated 2024-11-19.

p. 3 ↗, p. 4 ↗

QA NOTES

Ambiguity stays visible

Official PDF cover/permit heading checked in the manual second pass.
Permit allows manufacturer/model alternatives. — Value transcribed from official permit equipment/condition table; no totals calculated.
Value transcribed from official permit equipment/condition table; no totals calculated.
Directly stated permitted limit; not an actual emissions value.

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