The Environmental and Social Benefits of "Jettyless" Infrastructure

The jettyless innovation is changing the import and export landscape, making projects possible without the cost and inflexibility of traditional fixed-jetty infrastructure. To better understand the benefits of jettyless infrastructure for energy transport, it is helpful to take a comparative look at alternative energy transport options, namely the construction of a loading and offloading jetty. 

Innovative technologies are changing the marine-based energy transport landscape. Floating, jettyless solutions demonstrate more flexible applications when compared to traditional solutions based on jetties and quays, it also leaves the marine environment in which it operates undisturbed.

This article analyses the environmental and social impacts of building and maintaining fixed marine infrastructure for the loading and offloading of liquids such as ammonia, CO2 and LNG. This is in no way an exhaustive analysis of the total impacts of fixed marine infrastructure, but rather an indicative assessment of the value proposition of floating loading and offloading infrastructure when compared to traditional jetties. This article will look at the main components of a traditional jetty with a particular focus on the resource considerations, greenhouse gas emission (GHG) profile of resources used, and the impacts of the construction, operation and maintenance of a jetty on local environments.

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What is a Jetty?

A jetty makes it possible to receive and offload fuels  to shore by sea transport. Jetties connect vessels to terminals for purposes of transferring liquids between ship and a shore-based terminal. The basic components of a conventional Marine Jetty Facility include:

• Marine trestle, or main jetty platform
• Loading and unloading platform
• Breasting and mooring dolphins
• Breakwater
• Dredged seabed
• Marine equipment including fendering, mooring hooks, docking system, line load and environmental monitoring systems, ship to shore link
• Transfer system
• Piping
• Fire protection systems and coatings

Traditional receiving and offloading jetties require large amounts of materials, manpower and capital to maintain the integrity of the structure and the fixed foundations and contact points to the seabed.

Resource Considerations

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Carbon profile of construction materials

Traditional construction resources and methods for building jetties carry a high carbon profile. Why is there a big emphasis on carbon profiling when it comes to greenhouse gas emissions? The emphasis can be attributed to the fact that any carbon dioxide has the highest global warming potential (GWP) and when added to the atmosphere will remain for sometime between 300 to 1,000 years. All this time, it will be contributing to trapping heat and warming the atmosphere.

Carbon profiling is a mathematical process that calculates how much carbon dioxide is put into the atmosphere per m2 of space in a structure over one year.  Embodied carbon, one part of a structure’s carbon profile understood by the carbon emissions in the production of the parts of a structure, is responsible for 11% of global GHG emissions and 28% of global construction sector emissions. Embodied carbon will be responsible for almost half of total new construction emissions between now and 2050.

An analysis of the carbon profile of the materials alone, not including the scope 3 emissions (or the emissions associated with the transportation of a good through the supply chain, also called “value chain emissions”)  of the footprint of transport and installation, yields high CO2 emissions. To understand the CO2 emissions associated with construction materials, the marine trestle length is the key parameter using a per meter unit rate. The marine trestle covers all associated piled foundations, pile caps, beam, decking, pipe rack supports, roadways, railing and markings. Although jetties vary in size, typical structures include steel piles and a concrete superstructure (deck) which contains approximately the following:

• 7 metres cubed/metre of concrete (not including pipe-rack concrete)
• 3.9 Metric Tonnes (mt)/metre of steel

Concrete has a high CO2 profile, with an average of 150kg of CO2 per ton of conventional concrete, a jetty can produce upwards from 16,666 kg of CO2 (1 ton is approximately .42 cubic meters in volume, therefore there are approx. 7000 cubic meters in a 1000M jetty, yielding 16,666.6kg of CO2). A significant amount of concrete is used for the construction of conventional marine trestles. The connection between the piles and trestle consists of reinforced concrete between each pile head with the reinforcement steel cage extending through the main body of the jetty. Concrete is poured in the steel cages used to reinforce the structure and the supply of the large volumes of concrete required for the trestle is generally supplied via barge.

To put this in perspective, the CO2 emissions of building a 1000m jetty with 7m2 concrete depth are equivalent to the CO2 emissions of 7442 litres of diesel. In terms of offsetting these emissions, the CO2 offset measure of planting trees, although an imperfect science, would require 102 trees to counteract the CO2 from the concrete used in a 1000m jetty. It is accepted that six tree seedlings grown for 10 years can offset approximately 1 tonne of CO2 emissions annually.

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The use of steel and other metals used to reinforce a jetty also carry a high carbon profile and in many cases are produced by the energy generated from burning coal. The production of steel emits approx. 2,000-3,000kg of CO2 per 1000kg of steel from a coal-based plant, or 700kg-1,200kg CO2 per 1000kg of steel from a gas-based. On average, 1.9 tonnes of CO2 are emitted for every tonne of steel produced. About 2.8MT CO2 per year are solely related to energy use in the iron and steel sector, about 8% of total energy-related emissions.

Based on the above average resource use of 3.9 Mt per metre, this assumes that a 1000m jetty contains 3,900 metric tonnes or 3,900,000kg of steel. In a best-case scenario, if the steel was produced from a gas-based manufacturer, the CO2 emissions for the structure alone (not including scope 3 emissions) would total between 2,730,000kg and 4,680,000kg. A typical passenger vehicle emits about 4.6 metric tonnes of carbon dioxide per year - therefore the production of steel for a jetty is the same as the emissions upwards of 1,017 cars.

Floating, jettyless transfer solutions are partly made of steel - however a fraction of the steel is used for these solutions, on average 200mt or 200,000kg of steel when compared to 3,900,000kg of steel for a 1000m jetty. Therefore, a jettyless transfer made with steel from a gas-based manufacturer will have CO2 emissions, but far less than a conventional jetty would have, on average 380,000kg of CO2 emissions which is equivalent to the annual emissions of 83 cars.

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Construction Waste

Building jetties and quaysides also comes with the cost of increased waste and pollution due to construction activities. Without a waste management plan, a construction zone’s waste will end up in the sea and nearby terrestrial ecosystems. Proper construction waste management for marine-based projects are complicated and costly. Additionally, during both construction and operation phases a jetty could generate hazardous waste consisting of used oil; empty containers of paints, varnishes, thinners and lubricating oil; rags containing oil and grease, filter materials and waste oil generated from bilge and slop oil.

Construction waste, including hazardous waste associated with construction disturbance and multiple construction vessels is always reported as “expected” from the environmental and social impact reports for marine jetty construction. Below is an excerpt of expected waste from an environmental summary for an LNG marine loading and offloading jetty.

           Table 1: Estimate of construction waste produced for a 1000m marine jetty

Other resource consumption and waste considerations during construction include fresh water use and drainage, hazardous waste from construction materials and human waste. In areas with water scarcity, construction sites may compete with local communities for available freshwater or freshwater will need to be transported, carrying a high resource footprint. 

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GHG Emissions during construction & operation

Additionally, during a construction phase of 12 months or longer, other significant greenhouse gas emissions apart from CO2  emissions due to combustion of motor oil fuel related pollutants nitrogen oxides (NOx), carbon monoxide (CO), sulfur dioxide (SO2) from multiple construction vessels, trucks, heavy machinery and from diesel-powered generators (generally 0.5 to 1.0 MW) on the jetty are released into the immediate area.

Exposure to SO2 or NOx for even short periods can cause adverse respiratory ailments including airway inflammation, bronchoconstriction, asthma symptoms, and increase the likelihood for hospital admissions, especially for those with underlying asthma or respiratory illnesses.

Both SO2 and NOx also harm health by reacting in the atmosphere to form sulfate or nitrate fine (small) particles (PM2.5), respectively. These PM2.5 particles are microscopic solids or liquid droplets that are so small they penetrate deeply into the lung and harm health. About 50% (or about one-half) of total PM2.5 in the air is formed from SO2 and NOx. Most of the rest of PM2.5 is formed from carbon released from vehicles, industry, forest fires, and biogenic sources such as trees.

Also cited from a jetty construction environmental summary is an estimation of combustion emissions from large, stationary machinery (dredgers, marine diesel consumed) discharged from exhaust system at approximately 16,800 metric tons. According to the EPA, this is the same as the CO2 equivalent to 18,000 pounds of coal burned. 

It is estimated that the combustion emissions from moving sources (pipe lay barge, marine diesel consumed) discharged from exhaust system is an additional 19,320 kg. According to the EPA, this is the same as the CO2 equivalent to 44.7 barrels of oil consumed. 

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Impacts of Construction, Operation and Maintenance

Dredging

Dredging is commonly used to allow for access of ships to terminal sites via jetties, disturbing the seafloor by stirring up sediment leading to increased suspended sediment and turbidity in the water column within the immediate area and down current from the source. These alterations to intertidal and nearshore ecosystem morphology can have a profound effect on the reduction of wildlife habitat. They also have the potential to alter water currents and wave climates and can affect the water quality necessary for the flourishing of biodiversity and community livelihoods related to fishing, shipping, tourism and transport. Dredging not only directly affects seabed morphology and the ecosystems of the seabed, but it also affects the ambient seawater quality as it increases suspended solids, clarity, temperature, pH, and salinity.

Additionally, maintaining proper shallow sea depth for requires costly and ecologically disruptive routine maintenance. Shallow, nearshore sea habitats, where jetties are constructed, are amongst some of the most productive ecosystems on the planet and are estimated to sequester nearly 10% of all carbon dioxide absorbed by oceans. They are an integral part of the Earth’s natural carbon sink in the fight against global climate change. Additionally, research has shown that one hectare of seagrass can soak up as much carbon dioxide each year as 15 hectares of rainforest.

In terms of physical displacement of seabed, typical trench soil and rock displacement from dredging for a medium-sized jetty (approx. 1km to 1.5km) can displace approximately 2,500,000 cubic meters during initial construction to provide the required navigable depth of 8 m below lowest astronomical tide. This is the equivalent of filling 1,000 Olympic-sized pools.

Pile driving

Jetties also require stable piles into the bedrock below the seafloor to anchor the main marine trestle. Apart from the carbon profile of steel piles used in marine jetties, sound pressure levels (SPL) and sound exposure levels (SEL) from pile-driving into the seabed can affect marine biodiversity in a variety of ways, most notably affecting fish shoals, marine mammals and sound-sensitive cetaceans during migration, hunting and echo-location. Pile driving has the potential to produce some of the loudest anthropogenic sounds that enter the marine environment, which can also carry thousands of miles.

Estimates of average peak sound pressure levels (in decibels, dB) for impact pile driving of 14” steel H pile is 200dB – Marine Mammal injury threshold levels are on average 220dB. Pushing the limits of SPL and SEL for marine life can have devastating effects, and it is theorised that high sound levels are responsible for mass cetacean strandings throughout the world.

To understand the effects of SPL and SEL in relatable terms to humans, one of the loudest recorded rock concerts was a Led Zeppelin concert 1969, totalling 130dB, which is loud enough to cause severe and irreversible hearing damage to humans, and akin to decibels produced by a land borne hydraulic press, which is 70dB below the sound produced by marine pile driving. 

Regular maintenance such as cleaning, weatherproofing, pipeline integrity and inspection, dredging, etc. is required to maintain a safe structure to transport cryogenic fluids without loss of containment or structure degradation. Operations and maintenance regularly produce waste and require high fresh water and energy inputs.

Life cycle analysis (LCA) is a method that evaluates environmental impacts—including life cycle GHG emissions, energy use, and water consumption—of various pathways along the supply chain, which enables comparison of different pathways in a consistent manner. Life cycle costing has a more financial focus, as it is the process of compiling all costs that the owner or producer of an asset will incur over its lifespan. These costs include the initial investment, future additional investments, and annually recurring costs, minus any potential value from salvaging or recycling.

An important part of determining both the jetty’s life cycle analysis and life cycle cost is the cost of decommissioning. Due to concrete degradation, erosion and steel corrosion, jetties often have a design life between 20 to 40 years after which the terminal owner needs to invest significant resources to either decommission or refurbish the jetty, subject to the current market situation. Decommissioning includes a structural design analysis and the removal of all subsea structures, pipelines, flowlines and moorings. New methods involving recycling and reverse engineering are increasingly used in decommissioning to reduce the waste associated with removing and dismantling infrastructure – but not only is this a costly process, but it also does not recycle all materials.

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Community impact 

Notwithstanding, there is also an impact to people and the communities located near import and export jetties. Historically overlooked in energy infrastructure projects, there are important considerations around visual impact, safety, and the use of the area for livelihood security.

Pride of place and cultural heritage are potentially affected by alterations to land and water landscapes with the construction of jetties as jetties permanently alter the physical and social geography of an area. Positive pride of place is psychologically linked to a sense of identity from where one comes from, and can elicit a series of behaviours that are of prosocial and caring character, and are related to the affective and cognitive aspect of people-place bonds. Alterations to visual impact and geography in some cases have demonstrated a breakdown in the pride of place effect and diminishing social cohesion and prosocial bonds of a community. 

Additionally, jetties can alter existing fishing, transport and shipping areas affecting traditional sources of income for nearby communities. The vulnerability of rural coastal communities is threatened by a variety of factors, including sea level rise due to climate change and man-made alterations to seabed morphology and fish stocks due to industrial activities. Building jetties can potentially be devastating to the ability of rural coastal communities to maintain adequate food stocks with the construction of infrastructure that changes the physical marine environment. 

As with any construction project there is always a risk to human safety with several month’s exposure on live construction sites, debris, direct and indirect pollution from the GHG emissions and waste associated with construction and operations. Additionally, a construction site with higher security risk can require a higher degree of security presence, safety facilities, with increased social instability due to security risks.

Jetty construction can also contribute to worse outcomes for climate adaptation. Jetty construction also carries the risk of coastal erosion, reducing the resilience of natural storm protection features from storm surges and sea level rise. As a result of the perpendicular positioning of jetties to the shore, jetties disturb naturally occurring  longshore drift and cause downdrift erosion. The length of the jetty is directly correlated to the impact on adjacent areas - the longer the jetty, the greater the erosion impact. 

In the larger conversation about climate adaptation, the communities most vulnerable to the negative effects of climate change are low-lying coastal communities subject to sea level rise. The presence of a jetty can impact the seabed morphology and contribute to more erosion, thereby reducing the natural capacity of the area to withstand sea level rise, causing the displacement of coastal communities.

Why go jettyless?

The term “jettyless” refers to a loading and offloading transfer system linking ships to onshore terminals without any fixed marine infrastructure. Jettyless loading and offloading floating technology energy transfer solution to save the environmental costs of constructing fixed infrastructure in marine environments, while also bringing clean energy to developing communities. Jettyless technology is designed to have a reduced life cycle cost and be easily repurposed according to energy demand. The jettyless solution confers the following benefits:

• Cost effective and environmentally sound, with an emphasis on expanding access to energy to improve the wellbeing of developing communities;
• Superior life cycle cost when compared to a traditional jetty, with a modular, scalable and multipurpose functionality for a variety of energy types;
• Can operate in environmentally sensitive marine ecosystems with no impact to the seabed;
• Compatible with innovative technologies such as keychain multiparty workflows and environmental monitoring;
• Significantly reduced visual and physical impact that does not permanently alter the immediate geography nor affect nearby communities;
• Adaptable to a variety of renewable energy sources including ammonia, bio LNG, hydrogen and to reduce CO2 emissions through carbon sequestration.

In addition jettyless solutions are cost effective and flexible alternative to CAPEX- and resource-intensive jetty constructions, simplifying project permitting applications and responding to strict environmental regulations. The agile nature of jettyless infrastructure allows for a wide range of applications, suitable for a wide range of vessels and terminals, for a variety of applications and for a variety of fluid types.

This article was co-written by Danielle Murphy-Cannella and Magnus Eikens