Google's first data center in France will be classed Seveso

Page 92

Since 2 November, residents of Châteauroux and the 13 other communes of the surrounding area can read the file that Google and RTE, France's grid operator, have put to public consultation. It runs 132 pages, under the National Commission for Public Debate (CNDP), until 10 January 2027. Google and RTE wrote it, CNDP guarantors were involved, and the Commission signed it off on 7 October. We read all of it, looking for water first, since that's the question that sinks data center projects in the US.

The sentence that stopped us is somewhere else, on page 92. From the French-language file: "The project will also be classified under the Seveso Directive, owing to the storage of fuel associated with the backup generators." Seveso is the European directive covering industrial sites that handle large quantities of hazardous substances, with stricter inspections and emergency plans attached. The classification itself will be pronounced by the State at the authorisation stage. The file talks of an "expected classification."

Google plans its first data center in France that it builds and operates itself on the Ozans development zone, in Étrechet, in the Indre département. About 200 hectares, six to eight buildings over ten to twenty years, the first by 2030. At full build-out, the file puts grid connection at 1,320 megawatts: 120 on the 225,000-volt network, 1,200 on the 400,000-volt network once the Éguzon-Marmagne line is reinforced. Google's announced cost is around $10 billion, servers and software excluded.

Water: the question Google has already answered

On water, the file answers with a design choice. Air cooling, closed loop: the water circulates in pipes like the coolant in a car radiator and doesn't evaporate. According to Google's estimates, each building needs 1,000 m³ to fill the loop once, 300 m³ for fire-fighting tanks, then about 10.4 m³ a day for sanitary use, roughly an office block's worth. No withdrawal from the water table is planned, in operation or during construction.

Those are the developer's figures, based on ongoing studies and the experience of other Google sites. But they describe a technology rather than a pledge: per the file itself, a data center that doesn't cool by evaporation doesn't use water to cool its servers.

We showed with the 2% figure that came from a Congressional report how often the data center water debate rests on shaky numbers. Here it's the mechanism that counts, and it fits on a diagram.

The 2027 studies are not a slip

The file says additional hydrogeological studies will be carried out "during 2027", in particular to confirm there is no significant interaction with the drinking-water wells. Read quickly, it looks as if Google is asking residents before it has the answer.

It isn't. That's simply the order set by the French environmental code. The prior consultation comes before permit applications are filed, while the project can still change or be dropped. Then come the impact study, which covers water, the environmental authority's opinion, and a public inquiry whose file must include the consultation's report (article R.123-8 of the environmental code). The file's calendar follows that sequence: studies in 2027, construction hoped for in 2028.

Demanding the impact study during the consultation is like blaming an architect for not bringing the construction drawings to the meeting where people decide whether the house gets built. Residents will find those studies, in full, at the public inquiry.

Seveso, because of the fuel oil

The real gap in the file is elsewhere. A data center doesn't stop when the power goes out: it keeps backup generators, here "powered by fuels of the fuel-oil type." Google says it is considering hydrotreated vegetable oil (HVO), provided enough is available at an acceptable extra cost. The fuel planned at the outset remains fuel oil.

That stock is what brings the site under the Seveso Directive, at the lower threshold, the first of its two tiers. For diesel and fuel oils, French regulation sets that lower threshold at 2,500 tonnes (heading 4734 of the nomenclature of classified installations, according to Ineris, the national industrial-risk institute). That is not an estimate of the stock planned at Ozans: it is the quantity at which regulation places a depot of these fuels under Seveso. The file gives neither the number of generators at the data center nor the quantity of fuel stored.

The only generator count it cites concerns RTE's two electrical substations: two 250 kVA units in each. For Google's own site, nothing.

Normally, these engines barely run. The file describes monthly and quarterly tests of 5 to 10 minutes, and an annual test of about half an hour. A backup generator is like a fire extinguisher: its presence matters far more than its use, which is exactly why you want to know what it sits on.

What the file doesn't connect

On page 72, the file itself says the Ozans zone lies within the catchment area of the Montet-Chambon wells, "priority wells" for the urban area's drinking water, in "a sensitive karst environment." Karst is limestone bedrock riddled with cracks and channels, a bit like a sponge with big holes: water moves fast, and whatever seeps in at the surface can reach the aquifer without passing through the layer of soil that filters it elsewhere.

Yet the water chapter treats accidental pollution only during construction: machinery, its hydrocarbons, a sealed unloading area. The backup generators' fuel appears in the air-quality chapter and in the risks chapter, which defers to a hazard study "during 2027." For the site's rainwater, the file does provide for oil separation before discharge into the zone's network: hydrocarbons are considered, but as traces on a car park. Across the 132 pages, not one sentence puts side by side the stock that makes the site Seveso and the aquifer the file calls sensitive.

That is not evidence of danger. The hazard study exists precisely for this, and the file notes that a Seveso site is subject to regular inspections and emergency plans. But it's exactly the kind of question a prior consultation lets people raise now: it covers the project's characteristics and impacts, not just whether it should happen.

A town that lost its mayor

The question isn't abstract in Étrechet. In September, its independent mayor, Florence Laurent, resigned along with her three deputies and a municipal councillor in protest at the project, AFP reported. The mayor of Châteauroux, Gil Avérous, takes the opposite line, defends the site, and says 13 of the 14 communes in the area back it.

When the consultation ends, the guarantors will publish a report within a month, and Google and RTE will then have two months to say whether they are going ahead, and how. The water question was answered before anyone asked it. The fuel oil question is still waiting to be asked, and the register closes on 10 January.