Município De Mariana and the Claimants identified in the Schedules to the Claim Forms v BHP Group (UK) Ltd (formerly BHP Billiton Plc and thereafter BHP Group Plc)

Hearing date: 17 th December 2025

Approved Judgment

This judgment was handed down remotely at 10.30am on 19 January 2026 by circulation to the parties or their representatives by e-mail and by release to the National Archives.

On 14 November 2025 the court handed down judgment in the Stage 1 Trial of this matter [2025] EWHC 3001 (TCC) (“the Judgment”).

For the reasons set out in the Judgment, the court's key findings were as follows:

i) The defendants are strictly liable as “polluters” in respect of damage caused by the collapse pursuant to Articles 3(IV) and 14, paragraph 1 of the Environmental Law.

ii) The alternative strict liability claim pursuant to Article 927, sole paragraph of the Civil Code does not arise.

iii) The defendants are liable based on fault in respect of damage caused by the collapse, pursuant to Article 186 of the Civil Code.

iv) The defendants are not liable in respect of damage caused by the collapse pursuant to Articles 116 and/or 117 of the Corporate Law.

v) The claim forms issued in the proceedings before the court contained sufficient information, as required by Brazilian Law, to stop time running for the purpose of limitation/prescription.

vi) Pursuant to Article 200 of the Civil Code, the criminal investigation and proceedings that were commenced in Brazil in November 2015 postponed the start of the prescription period until at least 2024.

vii) The ADIC CPA filed against Samarco on 17 November 2015 interrupted prescription in respect of all claims arising out of the collapse but such interruption terminated on 24 September 2018.

viii) The ambit of the thesis in Theme 999 is limited to public environmental claims, that is, claims for relief regarding the restoration of damage to the environment. It does not extend to claims for individual or collective compensation arising out of damage to the environment, which remain subject to the general rules of prescription.

ix) The prescription period for the claims is five years pursuant to Article 27 of the Consumer Defence Code.

x) The claims by the Municipalities and Utilities are subject to a five-year prescription period pursuant to the 1932 Decree.

xi) The Term of Commitment document entered into by Samarco, BHP Brasil and Vale on 26 October 2018 is of no assistance.

xii) The general rule is that the prescription period starts from the moment at which the injury to the right occurs but subject to the characterisation of the injury; a distinction must be drawn between a single harmful event, periodic violations of right, and continuous violation.

xiii) Certain claimants may be entitled to extended prescription periods, by reference to (a) filing of protests in Brazil, (b) lack of capacity and/or (c) their date of knowledge. It would be a matter for the court, in each case, to determine these issues on the facts.

xiv) The settlement agreements are regulated by the general principles of contractual interpretation contained in the Civil Code. The Consumer Defence Code does not apply to the settlement agreements because there is no underlying consumer relationship between the parties and the settlement agreements are not consumer contracts.

xv) The court has determined the issues of construction and principle arising in respect of the sample settlement agreements.

xvi) There is no constitutional impediment by way of incapacity for the Municipalities to bring proceedings in this jurisdiction and they have standing in these proceedings.

This is the Consequentials Hearing following hand down of the Judgment. The matters that arise for determination by the court concern:

i) the claimants' application for costs, including whether any immediate order should be made, the scope of any costs order, and any reduction for issues on which the claimants lost;

ii) the claimants' application for a payment on account of costs;

iii) the claimants' application for pre-judgment interest on costs;

iv) the claimants' application for an order that there should be a detailed assessment of costs forthwith;

v) the defendants' application for permission to appeal.

Costs

The claimants' position is that they are the successful parties and, as such, seek an order that the defendants pay their costs of the whole proceedings up to conclusion of the Stage 1 Trial, such costs to be subject to a detailed assessment on the standard basis if not agreed. The claimants' costs up to conclusion of the Stage 1 Trial are £189 million and a payment on account of such costs is sought in the sum of £113.5 million, together with pre-judgment interest.

The claimants rely on the first witness statement of Alicia Alinia of the claimants' solicitors dated 9 December 2025 and her second witness statement dated 15 December 2025.

The defendants' position is that no immediate order in respect of costs should be made until after the Stage 2 Trial, when the question of overall success will be much clearer. If, contrary to their primary case, any order for costs is made, such costs must be limited to the costs of the Stage 1 Trial, there should be a percentage reduction to reflect the parties' relative success and failure on issues, the level of any payment on account is outrageously high and there is no entitlement to pre-judgment interest on costs.

The defendants rely on the 28 ^th witness statement of Efstathios Michael of the defendants' solicitors dated 12 December 2025.

Applicable costs principles

The court has discretion as to whether costs are payable by one party to another, the amount of those costs and when they are to be paid: CPR 44.2(1).

The general rule is that the unsuccessful party will be ordered to pay the costs of the successful party, although the court may make a different order: CPR 44.2(2).

CPR 44.2(4) provides that in deciding what (if any) order to make about costs, the court will have regard to all the circumstances, including:

(a) the conduct of all the parties; and

(b) whether a party has succeeded on part of its case, even if that party has not been wholly successful.

CPR 44.2(5) provides that the conduct of the parties includes:

(b) whether it was reasonable for a party to raise, pursue or contest a particular allegation or issue;

(c) the manner in which a party has pursued or defended its case or a particular allegation or issue; and

(d) whether a claimant who has succeeded in the claim, in whole or in part, exaggerated its claim.

The court may make an issue-based costs order but, before doing so, will consider whether it is practicable to make an order limiting the costs payable to a proportion of the overall costs: CPR 44.2(6) & (7).

Where there is a split trial, the court is entitled to exercise its discretion to make an immediate order for the payment of costs in respect of the liability trial but may defer the issue of those costs until the final outcome of the litigation, especially if it is unclear whether the successful party will recover more than nominal damages: Weill v Mean Fiddler Holdings Ltd [2003] EWCA Civ 1058, at [31] to [34].

However, as a general rule, costs should follow the issue, regardless of when the issue is determined, particularly in complex disputes, to encourage the parties to adopt a proportionate approach to the litigation by focussing on the significant and meritorious points: Langer v McKeown [2021] EWCA Civ 1792 at [36]–[38]; Illiquidx Ltd v Altana Wealth Ltd [2025] EWHC 1566 (Ch) per Rajah J at [8].

The fact that a party has not won on every issue is not, of itself, a reason for depriving that party of part of its costs. In the absence of unreasonable conduct in pursuing or resisting an issue, the general rule is that the successful party should have their costs and should only suffer a reduction to the extent that the costs were increased by the taking of the issue on which they failed: Sharp v Blank [2020] EWHC 1870 (Ch) per Sir Alistair Norris at [7](a)-(g).

Timing and scope of costs order

In this case, the claimants have obtained substantial findings of fact and law in their favour against the defendants on key issues of liability. Although there is no certainty as to whether, or to what extent, the Judgment will ultimately result in substantial damages for any specific claimant or group of claimants, the issues determined by the court were identified as the significant issues of liability raised by the claimants and the defendants. In those circumstances, it is appropriate for the court to make an order in respect of the Stage 1 Trial costs.

For the reasons set out in the Judgment, the court found in the claimants' favour on key issues of liability, namely: strict liability under the Environmental Law; alternatively, fault-based liability under the Civil Code; limitation/prescription; and standing/capacity of the Municipalities. Therefore, the claimants should be regarded as the successful party in the Stage 1 Trial and, as a matter of principle, are entitled to recover their costs...