The planned gas pipeline on the bottom of the Baltic Sea will run through old sea mine defence lines. During World War II in excess of 100,000 sea mines were placed into the Gulf of Finland. It is considered one of the most heavily mined sea areas in the world.
After the war the mines were cleared by cutting their attachment wires so that the mines would not surface. The explosive devices then sank to the seabed.
From the planned route of the gas pipeline such sunken mines have been found.
Primarily they are in international waters at a depth of more than 70 metres.
The plan is to detonate the mines underwater, explains the Russian-German Nord Stream consortium responsible of the intended pipeline project, in its draft for the estimation of the undertaking’s environmental impact.
The draft maps out those mines that will get in the way of the planned pipeline. The pipeline will be installed by a wide surface vessel relying on 12 heavy anchors to secure its position. The possibility of mines getting in the way of the anchors has not been looked into.
Environmental authorities now require further explanations as to how Nord Stream plans on ensuring that the mines within the installation vessel’s anchoring zone will not present a danger.
Finland’s Defence Administration is satisfied with Nord Stream’s mine charting and with the plans on how to destroy the mines that are found.
“The way the company plans on neutralising the weapons is standard mine demolition”, says Commander Kari Aapro from the Ministry of Defence. “The mines will be detonated at the bottom of the sea. Every detonation will be filmed and a diving robot will ensure that the mine has indeed been destroyed.”
Up until the 1960s both chemical and conventional ammunition were deposited in the Baltic Sea.
During both world wars the sea was mined and afterwards the weapons were sunk into the sea bed. The surrounding countries have also buried chemicals in the sea.
The laying of the planned gas pipeline requires the carrying out of an environmental impact assessment (YVA) in the same fashion as when building a new road or setting up a large pig farm. The assessment looks into the project’s effects on nature and people.
If the effects are regarded as unreasonable the project can be shelved. Requests can also be made for the plans to be altered.
An YVA is not a building permit. That has to be applied for separately.