GAIL (India) Limited, a government of India undertaking under the Ministry of Petroleum and Natural Gas, will lay sub-sea pipelines from the gas terminal of Petronet LNG Limited (PLL) at Vypeen in Kochi to National Thermal Power Corporation (NTPC), Kayamkulam, for transportation of re-gasified LNG (liquefied natural gas). Out of the 120 km pipeline, 117 km will be offshore while 1.5 km each will be on-shore at Vypeen and Kayamkulam.
A feasibility study was conducted earlier by EIL, an engineering consultancy company, for the project to supply LNG by means of pipelines to be laid on the Kochi-Bangalore-Mangalore and Kochi-Kayamkulam routes. The PLL terminal is to be commissioned in the last quarter of the financial year 2011-12, according to the company.
A detailed route survey of onshore and offshore areas was carried out by GAIL through a consultant firm. An environment impact assessment was also done by a professional team, according to petroleum industry sources.
A public hearing on the environmental issues associated with the sub-sea pipeline project is to be held in Alappuzha next month. It is part of the procedure for getting environmental clearance from the authorities for the pipe-laying project.
The pipeline from the terminal in Kochi will cross the shore approach area at Vypeen up to a water depth of 30 to 35 metres and then southward. The pipeline will run parallel to the shore up to Kayamkulam and then turn eastward till Kayamkulam coast. It will continue in the same direction on the coastline to reach the NTPC Kayamkulam power plant.
The pipeline portion in shore approaches will be buried below the seabed. Beyond these limits, the pipeline will be laid on the sea-bed in 30-40 metre water depth. The offshore pipeline will be coated with coal tar enamel (CTE). A concrete coating shall be provided over the CTE coating for anti-buoyancy and stability, according to the feasibility report.
As part of the study, an observation of the variety of fish existing in the coastal waters in the area was made. It revealed the presence of shark, catfish, sardine, pomfret, mackerel, seer fish, tuna, prawns and crabs.
The offshore pipeline will be installed by ‘lay-barge,' having a welding station and lifting crane. The pipeline on the approaches will be installed by fabricating the pipeline string on the lay-barge and pulling it on-shore or vice-versa.
The project is considered as eco-friendly in nature, according to the study reports. The re-gasified LNG will replace Naphtha, currently being used at NTPC. No significant vegetation or agriculture will be affected by the project. No rehabilitation issues are involved. The construction phase is expected to generate employment opportunity in the skilled as well as unskilled categories, industry sources said.
The potential sources of pollution that may affect water quality in the area could be soil runoff from the project. Improper disposal of construction debris may lead to off-site contamination of water resources. The guidelines issued by ports authority are to be followed for work in coastal areas.