California judge orders full environmental review of 330 MW Imperial County data centre
The ruling treats substation, batteries, generators and water tanks as one project, and shows why a data centre is really a power project.
A judge in California's Imperial County has ruled that a proposed 330 MW data centre cannot proceed on the strength of the approvals it currently holds, according to a report published on 1 September by Data Center Knowledge. Judge L. Brooks Anderholt of the Imperial County Superior Court issued a tentative ruling requiring the county to set aside key approvals and complete a full Environmental Impact Report under the California Environmental Quality Act before construction goes ahead.
The project, put forward by Imperial Valley Computer Manufacturing, LLC, would place a 950,000-square-foot facility on roughly 75 acres south-east of Aten Road and Clark Road. Beyond the building itself, the plans include a 330 MW substation, an 862 MWh battery energy storage system, 132 natural-gas generators providing 330 MW of emergency generation, four 500,000-gallon water tanks, a six-acre retention basin, cooling and water-treatment plant, and transmission interconnections with the Imperial Irrigation District. The report describes the proposal as a data centre with an integrated set of power, water, battery and generation infrastructure.
The county had argued that its approvals were ministerial, meaning they involved no discretion and therefore fell outside CEQA review. The judge rejected that position and found that the county had improperly relied on a 2017 environmental review that did not consider the integrated set of infrastructure now proposed.
The case was brought by the City of Imperial. Its attorney, Alene Taber, argued that approving the project in pieces disguised the total impact of the whole. The parties have 20 days after notice of the final ruling to meet and confer on the terms of the writ and judgment.
Why it matters
Large AI-era data centres are no longer just buildings full of servers; they arrive with substations, generator farms, battery yards and water systems that would each be significant projects on their own. This ruling treats the campus as a single integrated development for environmental purposes, a view that other jurisdictions may adopt as similar proposals multiply. For operators, the lesson is that permitting timelines now depend as much on power and water infrastructure as on the data hall. For communities, it establishes that older reviews cannot be stretched to cover projects of a different scale.
950,000 sq ft data hall, 330 MW load
On roughly 75 acres south-east of Aten Road and Clark Road.
330 MW substation and grid interconnection
Transmission ties to the Imperial Irrigation District.
862 MWh battery energy storage
Roughly two and a half hours at full load if used alone.
132 natural-gas generators, 330 MW
Emergency generation sized to the entire facility load.
Water: four 500,000-gallon tanks, six-acre basin
Plus cooling and water-treatment plant.
What you can learn from this
A data centre is a power project with servers attached. The 330 MW figure describes the electrical load, and everything else on the site list follows from it: a substation to step grid voltage down, switchgear to distribute it, and backup generation sized to carry the full load if the grid drops. Operators design for the assumption that the utility will fail at some point, so on-site generation is rated at or near total demand rather than a fraction of it. That doubling of capacity, once for the grid and once for backup, is why the substation and generator figures in this proposal match.
Batteries and generators do different jobs. A battery system responds in milliseconds and bridges the gap while generators start and stabilise, and it can also shave peaks or provide grid services. Generators provide sustained power for hours or days but take time to spin up and need fuel. Dividing the 862 MWh storage figure by the 330 MW load gives roughly two and a half hours of full-load coverage, which indicates the battery is intended for more than a brief bridge.
Water sits at the centre of cooling decisions. Evaporative cooling removes heat cheaply by turning water into vapour, which is why large sites carry storage tanks and treatment plants. A retention basin manages stormwater and runoff from paved areas, and storage tanks provide a buffer if the municipal supply is interrupted. Alternatives such as closed-loop or dry cooling use less water but more electricity, so a site's water infrastructure reveals its cooling strategy before any engineering drawings are seen.
Environmental review is a design gate, not paperwork. CEQA and similar laws require a lead agency to assess a project's full effects before approving it, and courts have long rejected "piecemealing," where a large project is split into smaller approvals that each look minor. The reason is cumulative impact: a substation, a generator farm and a water system might each pass individually while together changing air quality, noise and groundwater in the area. Reviews are also time-bound, since a study from years earlier cannot reflect a project that has since changed shape.
Ministerial versus discretionary approval decides whether review happens at all. A ministerial permit is one where an official checks boxes against fixed standards and has no room to say no. A discretionary approval involves judgment, and that judgment triggers environmental review. Disputes over which category applies are common because the label determines how long, and how public, the process will be. In this case the court sided with the discretionary reading.
We teach this
How to use this in practice
Build a power budget for a hypothetical 10 MW data hall. In a spreadsheet, start with 10 MW of IT load, apply a power usage effectiveness of 1.3 to get total facility draw, then size backup generation at that total and a battery at 15 minutes of ride-through. Add a row that converts battery megawatt-hours into minutes at full load, so the unit conversion becomes second nature, and use a second tab to try 50 MW and see how the numbers scale. Done looks like a sheet where changing the IT load or PUE updates the generator and battery lines automatically.
Draw a single-line diagram of a campus power path. Sketch grid connection, substation, medium-voltage switchgear, transformers, UPS or battery, and the IT racks, with generators feeding in at the switchgear. Label the voltage at each stage and keep it to one page, since a single-line diagram is meant to be readable at a glance. Done looks like a diagram where you can trace what happens to the racks when each element fails, marking which failures the battery covers and which need the generators to have started.
Read one Environmental Impact Report summary from your own region. Most planning authorities publish these online; find one for any large industrial project and list the impact categories it covers, such as air, noise, traffic, water and biological resources. Most summaries run to a few pages and are written for non-specialists. Note which sections mention cumulative effects, since that is the concept at the centre of this case. Done looks like a checklist you could apply to a data-centre proposal to see which sections would be hardest to satisfy.
Look up your local grid operator's interconnection process. Find the published steps and typical durations for connecting a large load or generator in your area. If the operator publishes a queue, count how many large requests are ahead of a hypothetical new one. Done looks like a one-paragraph note on how long a 100 MW connection request would take to move from application to energisation, with the source linked.
Sources
- California Judge Orders Full Environmental Review of 330 MW Data Center — Data Center Knowledge
Our reporting is an original summary; full coverage is at the links above.
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