Gas Import Jetty & Pipeline Discussion

Yaringa Marine Park

Yaringa Marine Park

Yaringa Marine Park


After I visited the AGL discussion meeting in Hastings I came away with one main point that was disturbing and that is AGL is using figures and tests to water down the impact of the massive damage to the marine environment the Terminal will do.

The first item I noticed is AGL's poster claiming the amount of Litres in the North Arm, which is for the whole of the North arm, but in reality the impact AGL's contaminated water will have is confined to the area in line with and around the terminal which has a tidal flow of North South, so the use of the huge number of litres is very misleading, the number of contaminated litres is confined to the terminal north and south.

The tidal flow does not run east west so any testing in an eastward direction towards the shipping channel {this is what AGL are doing} is a waste of time as the water in question cannot travel in that direction, so why are they going to test it ? Is it the same reason they use all the north arm volume of seawater, to mislead everyone.

AGL claim this

"the extent of cold-water and chlorine toxicity effects are likely to be restricted to an area
approximately 200 m north and south and 60 m east and west of the discharge point in water
depth from approximately 12.5 m to 17 m. This represents an area of approximately 5 ha,
which is less than 0.5 % of the seabed in North Arm1"

This is not misleading this is not a print mistake this is a blatant lie, repeat: a blatant lie, devised by someone in AGL to make you think the water contaminated by the cooling and chlorine is small. What they are not saying is this area is tidal as is all of Westernport and that tide will carry the super chilled toxic chlorinated water a lot further than 200 metres, they also say the contaminated area, {note they agree to contaminated water} will be a mere 0.5% area of the north arm, again a misleading lie to water down the effects this will have. They use the whole of the north arm and in this case only around the terminal, when in fact it is the narrow area but at least 12 klms minimum, north and south of the terminal so it will be a much greater area than what they try to claim. At the AGL meeting they claim it will travel 6klm's !! so they have conflicting figures, when In fact the tide will carry that contaminated water over a 6 hour period into the Ramsar site at Tyabb bank, not good for any marine life including seagrass, but what AGL have not told anyone { I cannot find the words Marine Park anywhere in their publications}, and use a distance of 200 metres, is that this water will enter the Yaringa marine park, 7 nautical miles away, 7 nautical miles is 12.6 klm's. A figure of a 6 hour tide traveling at a average speed of 1.5 knots {2.7klms} is a distance of 9nm {16.2klms} that is an average speed, some tides will be much faster. So you can see the tides will take the super chilled contaminated water into the marine park.

The contaminated cold water will actually travel in the north south direction up to Quail Island from there it will continue to travel in a northerly then north east direction behind Quail Island towards Warneet via Watsons inlet, covering all the mangroves and seagrass, the other flow that will follow the Quail bank contour line will travel across Quail bank and along the edge in a north east direction flooding the whole of Quail Island and then heading east towards Rutherford inlet.

At the meeting and AGL spokesperson said "as each tide travels back and forth the water gets diluted as it moves across the North arm towards Eagle rock". In that statement he has admitted the flow will travel much further than the 200 metres but tried to mislead me. I have fished here for over 50 years and know the tidal flow and what he said will not happen and cannot happen. Observations show anything floating in the water around quail bank travel back and forth in the same area, meaning there is no cross flow that would go anywhere near Eagle rock. The other point I hope helps you understand is this, as the flow of water travels north then north east then east it is like a river bend where the water follows this direction around a bend with the bend being the Middle spit, dividing the north arm from the eastern arm and Quail bank, so that body of water has to follow the contour lines,  what that means is the flow around the top of the middle spit will be at a different speed than the water several nautical miles across on the Quail bank, which means the water cannot move across in a south east direction from Quail bank to Eagle rock.

Now back to the Marine Park. The state government legislated laws to protect the Victorian Marine park with no fishing, no mining no anything including damage accidental or wilful and have very heavy penalties including jail sentences if the law is broken. The question to AGL is how are you going to stop any marine life being affected by this super chilled water and chlorine seawater, the answer is it cannot. To have a water temperature during winter of around 11 deg C in the marine park then a flood of super chilled water of 5 deg C will have a massive effect on all marine life as they could not adapt in such a short time with the end result would be death. The effect of chlorine into a marine park is a great concern, if the increase is minimal then the seawater has changed so will that do any damage to the microscopic life living in the marine park, of course it will.

I keep using the word super chilled water and the reason for that is this, as the tides start to flow and for this purpose we will use an incoming or flood tide, it will vary in speed depending on the moon phase, so on the half moon it will run very fast very quickly after the turn of the tide, on a full or new moon it will be very slow to start the flood. Every 2 weeks the moon phase changes, 1st week full moon, 2nd week half moon, 3rd week new moon and the 4th week half moon.

So on a full moon depending on which month as some months the tide can be exceptional slow, so lets use that as an example. As the tide runs out nearing the bottom of the tide the flow slows and on these tides about 2 hours before the change, it will slow to almost a stop about an hour before the change, the problem with this is the seawater is slowly passing the suction pumps and being pumped into the terminal heating the liquid gas and therefore cooling the water by around 7deg C. When the tide is flowing at this speed of around 0.2 of a knot this is where it gets super chilled. We have an area of lets use AGL's very small distance of 200m from the terminal, the tide stops, the water that has been pumped out is at a stand still on the tide change which can last up to an hour or more, the intake is now pumping in water that has already been chilled and is now being chilled again and again taking the temperature down and increasing the amount of super chilled water. As the tide slowly starts to flood that same chilled water is chilled again. Where does this water go when the tide starts running in, north into the Marine park.

The other part of Westernport that has not had any discussion except from a mussel farmer at Flinders is the water has to have a dramatic effect on the marine life from sandy point to Flinders. The same super chilled chlorinated water will travel south as per the marine park but in a opposite direction, this water travels to Sandy point where is is travelling south, then turns around the bend and heads west. This water finds its way inside the middle bank and the mainland, this area is very shallow, the tide can run very fast in this area. The area is shallow with the deepest about 9 metres but most is 5 metres, the sea bed is sea grass with an enormous number of marine life species, all which could not withstand such a dramatic change in the environment. The Mussel farms off flinders would be badly affected with possibility of not producing any mussels.

I would like AGL to respond to what I have written, explain how you will 100% guarantee not one form of marine life will not be harmed in any way within the marine park and if you do can you provide us with the names of the volunteers that will put their hand up to go to jail and take one for the team ?


Re: Yaringa Marine Park


This is a very good informative post, thank you. I hope AGL are realizing that they cannot protect the marine park and this project should be abandoned immediately. I hope you can contact all the media and let them know so they can let all Australians no what is at risk. I too ask AGL why are you risking irreversible damage to a marine park?

Re: Yaringa Marine Park


Great information Rob!


Thank you for such a detailed analysis of the risks to Yaringa marine park.


I look forward to reading AGL's response to your comments.

Re: Yaringa Marine Park


I noticed AGL responded to other posts above this, so here we go again but this time I will ask a question.

If AGL cannot 100% guarantee that no harm in any shape or form will be done to the marine park will you withdraw your plans for the terminal at Crib point.

Tags (1)

Re: Yaringa Marine Park


I have noticed AGL do not or will will reply to anything to do with a marine park, why ? It is not hard to give an answer to the basic question of "Can you {AGL} guarantee that no harm whatsoever will come to the Yaringa Marine park."

Your answer has to be a yes or no, nothing else nothing more except if you say yes. No means the end of your terminal a yes will need a very detailed explanation.

Re: Yaringa Marine Park

AGL Employee

Hi RobH1,


Due to the complexity and detail of your question, we are putting together a response that will address each point.


As we have received a large number of enquiries relating to the project, we are working hard to answer all of them as soon as possible. 


I hear your frustration with how long we have taken to respond, and I agree that we should be more responsive.




Re: Yaringa Marine Park

AGL Employee

Hi @RobH1 


We are not expecting you to trust us and we recognise the community can’t simply take our word that environmental risks will be well managed.


The purpose of the EES process is to independently assess if these risks can be addressed before the project is approved by the Victorian Government and many other regulators.


In addition to the EES, AGL (and APA) will be subject to oversight by numerous regulators and government agencies, including: 

  • Environment Protection Authority Victoria
  • Australian Maritime Safety Authority
  • Transport Safety Victoria
  • Marine Safety Victoria
  • Office of Transport Safety (Cth)
  • Energy Safety Victoria
  • WorkSafe Victoria
  • Harbour Master
  • Victorian Regional Channels Authority
  • Port of Hastings Development Authority

The project must adhere to several legislative requirements, including:

  • Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)
  • Environmental Effects Act 1978
  • Flora and Fauna Guarantee Act 1988
  • Victorian Advisory Lists
  • Planning and Environment Act 1987
  • Mornington Peninsula Planning Scheme
  • Guidelines for the removal, destruction or lopping of native vegetation (DELWP 2017a)
  • Catchment and Land Protection Act 1994 (CaLP Act)


The claim you referred to is from the Marine Ecosystem Protected Matters Assessment, located on page 4. This was a preliminary investigation and undertaken by CEE Environmental Scientists and Engineers, not AGL. Jacobs Group was engaged by AGL to undertake planning and environmental assessments for the AGL Gas Import Jetty Project. Jacobs engaged CEE Environmental Scientists and Engineers to define the marine environmental characteristics and identify key potential risks to the marine environment from the development and operation of the Project.


The studies concluded;

“The general outcome of the reports indicates that the direct effects of the full-scale operation of the FSRU on the marine ecosystem in the Ramsar area relate to discharge of cold-water, discharge of residual chlorine and entrainment of larvae and plankton. As stated above, the extent of cold-water and chlorine toxicity effects are likely to be restricted to an area approximately 200 m north and south and 60 m east and west of the discharge point in water depth from approximately 12.5 m to 17 m. This represents an area of approximately 5 ha, which is less than 0.5 % of the seabed in North Arm. Entrainment of up to 10 percent of some plankton and larvae may extend to 750 m north and south from the FSRU, but overall entrainment in North Arm is expected to be less than 1% of the whole of the North Arm. The predominant habitats in the area that may be affected are: bare soft seabed habitats occupied by invertebrate communities (infauna and epibiota) and some mobile fish, and; planktonic communities in the constantly moving water column of the main North Arm channel.


The longer-term effects of entrainment on planktonic populations (including some planktonic larvae and eggs) are uncertain due to the possible intermittent and variable operation of the FSRU which depends on uncertain national and state energy supply options and state energy demands in the near future and over the next decades. The duration of operation will depend in multiple factors including security of energy supply and raw energy supply markets.”


The expert authors did not consider there is any impact on the Yaringa Marine Park. You are welcome to provide an alternative view but because they disagree with you doesn’t mean they are lying or trying to be misleading.


We rely on the advice of qualified marine experts and the claims are not devised to be misleading in anyway.


We want to use this forum as place for respectful and open discussions between AGL and those concerned about or interested in the project. We understand that there are many who may disagree with us. However, accusing us of lying is not in the spirit of our forum. We would like to reiterate that the information we have received is the opinion of third-party experts.


Potential environmental impacts will be subject to deeper investigation in the EES process. The scoping requirements are located here: 


As stipulated in the EES:  

“Minister’s decision to require an EES included the procedures and requirements applicable to its preparation, in accordance with section 8B(5) of the Environment Effects Act (Appendix A). These requirements included the following key matters for the EES to examine: 

  • effects from seawater intake to and cold water/residual chlorine discharges from the gas import jetty facility, including potential medium and long-term effects on the ecology of the North Arm of Western Port associated with changes to seawater quality and entrainment of larvae of marine species (threatened and non-threatened)” (p.3) 

Furthermore, in relation to chlorine and water temperature, the EES requires: 

  • identification of the marine or intertidal fauna and flora that could be affected directly or indirectly by the FSRU, including but not limited to entrainment through pumping system, susceptibility to changed water temperature or susceptibility to discharges containing chlorine or other pollutants. (p.14) 

The Minister for Planning will decide on the suitability of the project. As the EES process is the most rigorous avenue for obtaining government approvals, without the Minister for Planning’s assessment that the project would have an acceptable level of environmental effects, AGL would not be able to pursue the project. 


We encourage all community members to submit their concerns so they can be input to this assessment.


It is impossible to 100% guarantee no marine life will be harmed in any way, and we realise for many in the community, this is not good enough. To even consider this project, we must plan for any possible failures (the worst-case scenarios) assuming they could happen no matter how unlikely.

These will all be reviewed independently as part of the EES  process.


It also needs to be remembered that the proposed project is still in the feasibility stage. The AGL Board have also yet to decide to fund the proposed project. A final investment decision will not be made until the final EES assessment is complete. 

Re: Yaringa Marine Park


Thank you for your reply but there are some parts that I am not quite understanding. You wrote;

"We are not expecting you to trust us and we recognise the community can’t simply take our word that environmental risks will be well managed.

The purpose of the EES process is to independently assess if these risks can be addressed before the project is approved by the Victorian Government and many other regulators."


Then you wrote "This was a preliminary investigation and undertaken by CEE Environmental Scientists and Engineers, not AGL. Jacobs Group was engaged by AGL to undertake planning and environmental assessments for the AGL Gas Import Jetty Project. Jacobs engaged CEE Environmental Scientists and Engineers to define the marine environmental characteristics and identify key potential risks to the marine environment from the development and operation of the Project."

I read that as they were working for AGL ?

Then you repeated what my post was about when you wrote this "As stated above, the extent of cold-water and chlorine toxicity effects are likely to be restricted to an area approximately 200 m north and south and 60 m east and west of the discharge point in water depth from approximately 12.5 m to 17 m. This represents an area of approximately 5 ha, which is less than 0.5 % of the seabed in North Arm.

And I and everyone else is to believe this. If a scientists wrote that he lives in another world than me,  you can read my post again about the tides, the lie on the whole of the north arm just to name a few, whoever wrote that rubbish does not know that Westernport has tides nor do they understand how,why and where tides flow.

I also pointed out that there is no mention of a Marine park in any of your documents, is that because a company employed by AGL stated that there will be a 200 mt area that will be affected ? Obvious no one has tested to see how far the tide of super chilled water will travel, something I thought would be  one of the first tests you would do knowing there is a marine park north of the terminal.


Re: Yaringa Marine Park

AGL Employee

Hi @RobH1,


We're going to check with the experts about the issues you have raised. This may take some time, but we will get back to you as soon as possible.

Thank you for your patience.

Re: Yaringa Marine Park


Hi @RobH1 


I am from CEE Environmental Scientists and Engineers.


There are several interesting points made in the post about the extent of travel of temperature and chlorine discharged at Crib Point.   This first response considers the travel, dilution and effects of the temperature discharge (which involves tidal flows, mixing and the energy balance for WPB) while a subsequent response will consider the travel, dilution and chemical transformations of chlorine.


Western Port is dominated by the inflow and outflow of seawater each day due to the tides.  The semi-diurnal tides are the largest (peak range of about 1.9 m) while the diurnal components are smaller (peak range of 0.7 m).  As a result, there are two tides each day (as the semi-diurnal components are the largest) but a pronounced spring tide to neap tide variation due to the diurnal components.


Currents have recently been measured across Western Port at Crib Point for the AGL project using acoustic doppler current profiling loggers. These instruments measure currents in 1 m layers from the seabed to the water surface. The plot below shows north/south (blue line) and east/west (red line) tidal currents measured in the mid-water layer near Crib Point Jetty from 19 March to 16 April 2019. The period of record starts during neap tides (low current speeds), progresses through the spring tide high current speeds), then neap, then spring and finishes during the third neap tides of the deployment. In spring tides, the north current reaches about 0.6 m/s (on the flood tide) while the south current reaches about 0.8 m./s (on the ebb tide).    In neap tides, the peak north current is 0.4 m/s while the peak south current is about 0.45 m/s.  



For this set of measurements, there is a net south current at Crib Point jetty averaging about 2 km/day: the southward water movement on the ebb tide are generally larger than the northward water movement on the flood tide.  There can be periods of a net northerly current in particular wind and tide conditions, although it did not show up in the month of current metering.


The current measurements also show a consistent east current, although much smaller, at about 0.38 km/day.  This is apparent in the figure where the east (positive red) currents are generally larger than the west (negative red) currents, resulting in a net movement of water to the east over a tide cycle.


The peak northward current speed of 0.6 m/s implies a net water movement to the north (in the flood spring tide) of 8.6 km.  This would transport water from Crib Point to about opposite the Bluescope Jetty.   The peak southward current would transport water from Crib Point to about opposite the Ventnor.


These movements are for water and a conservative constituent in the water.   But not temperature, which is a dynamic property of water and varies over the day (due to the combined effects of solar radiation, evaporation and transfer of heat between the atmosphere and the surface water).  Temperature also varies over the year (from about 10 to 24 degrees C in northern Western Port, which is shallow, to about 11 to 21 degrees C in southern Western Port, where the water is deeper and more affected by the temperature in Bass Strait waters).    On any day there can be a 1 to 4 degree C difference between the water temperature in northern Western Port compared to the water temperature in southern Western Port (check for data on Western Port water temperature).


Often there is a 1 degree C variation in the water temperature over a vertical profile – particularly apparent when warm water from over the mudflats flows back into the deeper channels.   The point about this description about water temperature variations in Western Port is to demonstrate that water temperature varies from day to day and with distance along North Arm.  


Natural gas is liquefied to form LNG by lowering the temperature to approximately minus 160 degrees C, which I would term “super-chilled”.    AGL are considering returning the LNG back to a gas by heating it with seawater, and the heat-exchange process will result in about 5 m3/s of seawater being discharged back to Western Port via six discharge ports at seven degrees colder than the surrounding seawater.


The ports discharge horizontally at a velocity of 5 m/s, which creates intense mixing over the path of the seawater jets from each port.   The typical dilution over the path of each discharge jet is 20:1, which will change the temperature in the jets from 7 degrees C cooler than ambient at the discharge point to just under 0.4 degrees C cooler than ambient near the seabed.


The dilution prediction can be checked by considering the ratio of the volume of water in the jets to the volume of seawater passing the vessel in the path of the jets.  The jets discharge 5 m3/s of colder seawater (half on each side so there is 2.5 m3/s discharged on each side of the vessel).   The jets extend for 60 m from the vessel (see diagram below) in a water depth of 13 m.  At the mean tidal current speed of 0.3 m/s, the volume of seawater passing through the mixing volume is 234 m3/s (60 m by 13 m by 0.3 m/s = 234 m3/s).   The ratio of seawater flow to discharge is 93:1 (234 m3/s / 2.5 m3/s = 93).  If there was perfect mixing, the dilution would be 93:1.  But mixing is not perfect, and we estimate the actual mixing to be 20:1.  


In the jets at 60 m from the discharge point, the water temperature is just 0.4 degrees cooler than ambient – this could be termed “cooler” water.


So to clarify my terminology:

          Superchilled = LNG at -160 degrees C

          Colder seawater is 7 degrees C below ambient

          Cooler seawater is 0.4 degrees below ambient.



Image 2.png

Next we discuss what happens to the patch of cooler seawater.  It simply mixes with the adjacent seawater as it is carried up and down Western Port by the tidal currents


Attached are four videos representations of the rate of mixing of the cooler water from 0.4 degrees C to 0.1 degrees C.   This reduction in temperature occurs within about 200 to 400 m, within the confines of the Port area.


After that, the slightly cooler water continues to mix with the Western Port waters.   The measurements indicate the patch (which will become very large and have so little temperature difference, perhaps from 0.01 to 0.001 degrees C, that it will be very difficult to measure due to the larger natural variations in water temperature.


Even so, fundamental laws of physics tell us that energy must be conserved.So how will this be achieved?  The answer is that the ever-so-cooler Western Port water will radiate less energy into the atmosphere and evaporate less water into the atmosphere (counter global warming, but not nearly to a noticeable extent).    According to the CSIRO, evaporation is expected to increase by 2 % to 8 % with global warming  The theoretical reduction in evaporation due to the cooler water discharge will be a small fraction of the projected increase.


There is no chance that cooler water will accumulate in the Marine Park or at Flinders.   There are two reasons for this statement.

  1. Mixing in tidal currents will reduce the temperature in the ever-expanding patch to such a small difference that it cannot be detected (and certainly the patch cannot hang on as cold water in a dynamic environment with strong currents and mixing);
  2. The daily energy balance will marginally reduce heat transfer from Western Port waters to the atmosphere maintaining thermal equilibrium, with undetectable change from the present condition (not allowing for climate change in the future).

Neap Fall Slow


Neap Rise Slow


Spring Fall Slow


Spring Rise Slow

Consulting Environmental Engineers (CEE) Hydrodynamic Consultant