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Protecting the environment

Our Environmental Management System is fully compliant with the environment management standard ISO 14001. We focus on adhering to all applicable international and local environmental legislation. We also track our performance by monitoring data such as energy efficiency, emissions and waste. In addition, we are members of the UN Global Compact and particpate in Carbon Disclosure Project, ensuring we measure and manage our environmental impact. 

Climate change prevention

As a key contributor to the offshore subsea construction industry we support our clients in reducing their greenhouse gas emissions through cost and energy efficiency developments:

  • Front-end engineering and design solutions to meet our clients’ aspirations for reducing emissions of greenhouse gases.
  • Design, engineering, procurement and installation of offshore renewable energy projects in the areas of offshore wind, wave and current.
  • Increased use of subsea oil and gas infrastructure to reduce the need for topside structures and processing. In turn, this reduces costs, energy demand and emissions for development and operation during the life span of the field.
  • High focus on R&D and technology development.
  • Supply chain improvements (supplier performance assessment, supply chain innovation in connection with our Technology Group).

In addition we actively promote energy efficiency and atmospheric emission reductions in our own operations to help prevent climate change.

Reduced atmospheric emissions

Over 90% of our own atmospheric emissions comes from the operation of our fleet of vessels, which includes pipelay and construction vessels, dive support vessels, windfarm support vessels and heavy lift vessels. Over the last two years our fleet has seen a renewal, with older tonnage leaving the fleet and being replaced with newer and less polluting vessels.

CO2 emissions

As a consequence of the type of activities we are involved with, our own energy usage and associated emissions reflect a combination of the work schedules of the vessels throughout the year. Our focus has therefore been to improve the energy efficiency of the ongoing activity.

Our Clean Operations programme continues to drive down emissions and ensure efficient energy management. The programme started in 2011 with the aim to raise the awareness of energy efficiency among the ships’ crew as well as the onshore and offshore project staff and to save fuel without compromising the safety or execution of our operations. Focus has been on improving the power management of the ships’ engines as well as reducing the operational energy demand. Clean operations are recorded as energy savings beyond a normal operating practice baseline for various operations.

From January 2019 all Subsea 7 ships above 5000 Gross Tonnage (GT) are reporting fuel consumption, distance sailed and hours underway in compliance with the IMO Data Collection System. These data will annually be externally verified by an accredited company and submitted to IMO.

NOx emissions

NOx emissions are generated from combustion of hydrocarbons. With the renewal of our fleet we have reduced the NOx emissions from our marine diesel engines. Three of our newest ships has been built with catalytic reduction (SCR) which eliminates about 75% of the NOx emissions from the exhaust. These ships are also registered with an Environmental Ship Index (ESI) in the World Ports Sustainability Program which has the objective of reducing CO2 emissions from transport and improving air quality around their ports. 

NOx reducing technology (SCR) is also included for a new ship currently under construction. 

Subsea 7 is member of the Norwegian NOx fund and are contributing to development and installation of NOx reducing technology. All of our ships are members of the Norwegian NOx-fund.

SOx emissions

Sulphur content in marine fuels is regulated through IMO. In Emissions Control Areas (ECA) the maximum allowable sulphur content 0.1%. This also applies to all ports within the European Union. From 1st January 2020 a limit of a maximum of 0.5% sulphur content will be introduced to all other sea areas outside the ECAs.

All of our ships are able and ready for running on low sulphur fuel. No conversion of engines or installation of exhaust scrubbers are required, which would otherwise introduce additional problems of polluting sea discharges. Most of our ships are already using low sulphur marine fuel whenever it is available.

Energy efficiency

Our Clean Operations programme both drives down emissions and ensures efficient energy management. We target to save more than 5% of vessel fuel in 2019 using Clean Operations. In addition, one of our ships, Seven Viking, has been converted to hybrid battery – diesel electric operations in order to improve the energy efficiency. The efficiency of engines of the vessel is optimized using additional battery capacity by up to 20%.

Our vessels are the primary source of energy consumption but we also look at improving efficiency in other areas such as our offices. The Subsea 7 office in Sutton, UK was specifically designed for sustainability and energy efficiency receiving a BREEAM excellent rating. Some of the environmental features include:

  • Brown roofs including a 320m2 photovoltaic roof array, which generated over 38,000 kWh in 2018
  • Rainwater recycling tanks to harvest water
  • Combined heat and power units & high performance chillers
  • LED lighting
  • Building management system with real time environmental performance display in reception. 

Spill response

Subsea 7 is committed to avoid any oil or chemical pollution from our activities whether from our onshore fabrication yards and supply bases or from operations from our ship. Our activities onshore and offshore are therefore subject to robust risk assessments and have procedures, routines, equipment and response plans in place to avoid spills and respond to any incidents if they occur.  Subsea 7 has a 24/7 emergency response centre to help and support in the event of an emergency. All our ships have Shipboard Marine Pollution Emergency Plans (SMPEP) which are subject to regular exercises.

All spills to the environment regardless of size are recorded and reported internally and externally to the relevant authorities. We have annual targets to reduce spill frequency and intensity.

In 2018 the number of spill incidents were less than 0.02 per USD million revenue and the amount of oil and chemicals spills were 0.3 litre per USD million revenue. Over 88% of spills were 10 litre or less.

Waste management

The waste management hierarchy used by Subsea 7 is based on the following priorities; Prevent, Reduce, Reuse, Recycle and Dispose.

Each work site will have its own waste management plan which will fully comply with all relevant international and local waste legislation. Only approved waste contractors can be used for collection, external treatment and final disposal of waste. Subsea 7 will verify that the waste contractors (and their subcontractors) have the appropriate licenses, equipment and capacity for the waste that is being handled. All waste generated by Subsea 7 worksites, operations, products or services shall be traceable. Any legally required documentation is to be retained as defined by the applicable legislation.

Recycling of ships

In the 2018 five of our older ships were sent for recycling. Subsea 7 has completed robust due diligence in selection of recycling yards and followed guidelines of the Hong Kong Convention for the Safe and Environmentally Sound Recycling of Ships, the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal, and the EU ship Recycling Regulations. In order to ensure safe and environmentally sound recycling we have our own people on site monitoring and supervising the activity in the yard. An inventory of hazardous materials aligned with the Hong Kong Convention has been prepared for all the recycled vessels.


In order to avoid the spread of unwanted marine species and pathogens from ship movements around the world, Subsea 7 has since 2010 implemented Class approved Ballast Water Management Plans aligned with the International Ballast water convention despite this convention not enter into force until September 2017. One third of our fleet have also already installed ballast water treatment plants which are compliant with IMO and U.S Coast Guard standards.

Spread of unwanted marine species can also occur as a result of marine growth on the ships hulls being transported around the world. Subsea 7 monitors the condition of the antifouling paint on a regular basis. Prior to entering environmentally sensitive areas, e.g. the Australian coast, the ships’ hull will routinely be cleaned.   

Supplier management

All suppliers we use are pre-approved and required to have an Environmental Management System in place with documented work processes and the required physical safeguards to prevent spills of oil or chemical substances to land or water. Suppliers are required to exercise all necessary care to protect and preserve the environment, including flora, fauna and other natural resources where we work.

We manage environmental Incidents & Near Misses involving our suppliers with Synergi Life Management System as described under HSEQ.


We track key environmental data such as fuel and energy consumption, carbon emissions, waste segregation, spills and other incidents. We monitor trends and performance and measure these against our targets.

2019 Targets

Environmental incident frequency rate <0.70 (lowered from <0.9) per 200,000 hours worked

Environmental spills <25 Litres per 200,000 hours worked

5% fuel saving on vessels resulting from clean operations

CO2 emissions normalised as Metric tons per million $ revenue

NOx emissions normalised as Metric tons per million $ revenue