A renewed application for a judicial review of the Environment Agency's decision to grant consent for the construction of a twin tunnel beneath an aquifer as part of works for HS2 has been refused permission by the High Court.
In Misbourne Environmental Protection Ltd, R (On the Application Of) v Environment Agency  EWHC 3094, HS2 had submitted its application for consent for the 16.04km tunnel to the Environment Agency, which is the drainage authority in this case, in February this year. The EA granted consent in April.
The claimant was a private company set up by various environmental groups with an interest in protecting the River Misbourne and the local chalk aquifer.
Mrs Justice Lang had dismissed a previous iteration of the claim before the case was renewed to Mrs Justice Lieven.
A compliance assessment in HS2’s application for consent concluded that the impacts of the tunnel construction on the Mid-Chilterns Chalk groundwater resource were "localised, limited and temporary".
However, the claimant argued that there were a number of features of the geology and the proposed construction methods that meant the conclusion was wrong as a matter of law under the Water Framework Directive (WFD).
In particular, the group's concern was that the tunnel boring machines would fracture the chalk, risking water loss from the River Misbourne and lowering the water in the aquifer. In addition, the group raised concerns that the grout used in the boring process could pollute the water.
The group advanced three arguments in their challenge. The first (Ground Two) challenged how the Compliance Assessment's categorised the impact of the work as "temporary", avoiding a trigger of Article 4(1) of the WFD.
The claimant argued that this approach was irreconcilable with the analysis in Bund Naturshatz v Bundesrepublik Deutschland C-461/13.
According to the claimant, HS2 (and thus the EA) focused only on permanent effects and failed to consider temporary but significant effects in its assessment.
Accepting that this ground was not arguable, Mrs Justice Lieven said: "Bund did not find that any deterioration of water quality triggered Article 4(1), there had to be a change in the 'status' of the water body. The concept of "status" must involve more than some purely transitory effect, however significant it might be."
The judge said that if there is a significant impact, but it has passed within a short period of time, then that would not amount to a change in the status of the water body.
She added that there was a judgement to be made over what period of time the effect must last for it to amount to a risk to the deterioration of the status of the water body.
HS2 had defined "temporary" as lasting three years which is half the life span of a River Basin Management Plan.
"A judge in the Administrative Court is not in a good position to decide whether 3 years is the right period or not for an effect to be considered sufficiently transitory as not to change the status," Mrs Justice Lieven said.
"However, the relationship to the timespan of the River Basin Management Plan gives a rational temporal relationship to the normal review of the river or aquifer's status."
Therefore, Judge Lieven accepted the approach as lawful.
Ground Two strayed into a challenge to HS2/the EA's professional judgment as to the extent of the risk, and how long it might last, the judge said. She said these were "not matters for judicial review".
The next ground of challenge (Ground Four) – specifically that the EA wrongly failed to require a discharge permit in respect of the grout that was produced by the tunnelling process – relied on the same issues as the previous ground, the judge noted, "namely that HS2 has not properly assessed the risks of discharge on the water bodies".
The claimant argued that the EA should have required HS2 to apply for an environmental permit under the Environmental Permitting (England and Wales) Regulations 2016 ('EPR') and, without such a permit HS2, was in breach of Regulation 12 and Schedule 22 of the EPR.
Mrs Justice Lieven considered the decision whether a discharge permit was required for the discharge of the grout through the tunnelling process was, “par excellence”, a technical one for the EA as regulator to consider.
She said that the documentation showed that HS2 had "fully considered all the relevant matters in reaching its conclusion".
"It was fully aware of the various factors that the Claimant has pointed to and, having assessed them, concluded that no permit was required," he added.
In light of this, Judge Lieven said she was satisfied that HS2 and the EA had considered the risk of discharge of bentonite and the risk of it getting into the groundwater. “They took into account both the nature of the grout and the water environment and concluded that the risk of grout migration (with mitigation) was extremely low. I do not think any arguable point of law arises.”
In the final ground, the claimant argued that the EA failed to properly consider cumulative impacts of the works (Ground One). In particular, it claimed that the assessment should have been updated to take into account the loss of polluting slurry in an incident at the new shaft at Chalfont St Peter.
In response, the judge said: "Given that there is no legal requirement to carry out an assessment of all the work together, this is again an issue where there is a considerable measure of professional judgement to be exercised. I accept HS2's argument that the shaft event was not legally connected to the decision under challenge. It was thoroughly investigated by experts who reported to HS2 upon it. Most importantly, the works in respect of the shafts are different in nature to those used in tunnelling."
Mrs Justice Lieven therefore refused permission to bring judicial review proceedings.