Article 4 applies to a deposit or works activity carried on wholly under the seabed in connection with the construction or operation of a bored tunnel.

Paragraph (1) is subject to conditions 1 to 3.

Condition 1 is that the activity must not adversely affect the environment of Wales, the Welsh inshore region and the Welsh offshore region or the living resources that environment supports.

Condition 2 is that the deposit or works activity does not or is not likely to cause obstruction or danger to navigation.

Condition 3 is that the deposit or works activity does not or is not likely to cause damage to features of archaeological or historic interest.

But article 4 does not apply to any such deposit carried on for the purpose of disposal.