Bro Tathan: what the screening file shows

Vale of Glamorgan Council has released its file on why the Bro Tathan data centre did not need an Environmental Impact Assessment. We also look at how the EU keeps data centres’ energy and water figures secret.

The screening file

In answer to a request made through WhatDoTheyKnow, the Council released 18 documents on 16 October 2026. They show that a Council planner first said informally that an assessment was likely to be needed; that the developer’s consultants disputed it; and that nine days later the Council decided none was needed, before several of its own consultees had replied. A month later the consultants’ own survey reported likely PFAS contamination and buried radioactive objects on the site. When a larger scheme, with 72 diesel generators, was approved in 2024, the Council relied on the 2022 decision.

The full story, with every document linked, is on the Bro Tathan case study. The documents themselves are on WhatDoTheyKnow.

Energy and water figures kept secret

The EU requires large data centres to report their energy and water use, but keeps the figures for each site confidential. An investigation found that the wording was copied from proposals by Microsoft and an industry lobby group. From 2027 the EU will publish a grade for each site, but still not the figures. The UK has no reporting requirement at all. See Water.

New questions

Four new questions are in the questions tracker: two on publishing energy and water figures, and two on Bro Tathan.