The channel into Emily Bay on Friday 19 July 2024, Norfolk Island
Four years ago, we had what amounted to nothing short of an environmental catastrophe in our lagoons. On the night of 30–31 July 2020, Norfolk Island experienced a downpour with 83 mm falling overnight sending a cascade of sediment, nutrients and pathogens into Emily Bay. The stench was horrific, the consequences afterwards, likewise, were horrific.
Testing, then and now
Here’s a little background to that event, and an explanation around the testing that was undertaken then compared to what is done now. I’ve kept it as simple as possible.
Below, and at this link, is the media release published on 3 August 2020 by Norfolk Island Regional Council (NIRC). It was transparent, direct and honest, spelling out what had happened and giving us detailed figures for the extent of the problem. The water quality testing for Enterococci, E. coli etc. at that time was undertaken by a qualified local contractor, Biotec, using traditional individualised testing methods.
Public Health Warning – very poor water quality in Emily Bay outlet.
Media release, Norfolk Island Regional Council.
Some time after this event, NIRC switched to testing the water with the Quanti-Tray 2000 test kits, used widely by government departments and buinsesses, and which are considered to be a more efficient and cost-effective way to detect bacterial contamination compared to traditional methods. Quanti-Tray test kits use the Most Probable Number (MPN) technique to quantify bacteria such as Enterococci in water samples.
For our purposes, the MPU is considered to be interchangeable with a CFU, ergo, 500 MPU/100 mL is the same as 500 CFU/100 mL.
I have given more detail regarding the testing at the end of this article for anyone who wants to know more.
A screenshot of the Quanti-Tray 200 kits, showing the different levels of Enterococci, taken from the NIRC website
Each Quanti-Tray 2000 test kit will count up to 2419 CFU/100 mL.
Importantly, for Enterococci, any result above 500 MPN/100 ml is described as ‘bad’ and a red alert is issued.
Traditional, individualised water testing for faecal contamination probably gives more detail than is necessary for NIRC’s purposes; although, having said that, it does give you a better idea of the real severity of the problem when you get results for Enterococci of 900,000 CFU/100 mL as we did back in July 2020.
Quanti-Tray kits are approved by NATA, an organisation that accredits laboratories to an international standard.
I’m explaining this so you understand that we are not comparing apples with apples. Biotec is not accredited by NATA (the market for water testing on-island is so small, it would be uneconomical for it to be so) and there are no guarantees (from NATA) that Biotec’s testing is 100 per cent accurate. But let’s be clear: that does not mean that Biotec’s results are inaccurate, or not fit for purpose. I have personally called on Biotec a couple of times to do testing for me when I have been uneasy about the water quality, most recently on Sunday, 21 July 2024, as I will now explain.
Emily Bay, reef health and the sand plug
I have been watching our reef with interest almost everyday over a period of six years (and for an almost five-year stretch back in the late 1990s). I know it intimately. I have been photographing life on the reef and cataloguing it since January 2020.
I became interested in the reef because I believed it wasn’t faring so well since I had swum there regularly in the 1990s. Even so, in 2020 we were in the midst of a drought, and although I didn’t realise it then, I was seeing and photographing fish species that would become difficult to find once the rains came and fresh water flushed more regularly into the bays, which it certainly did, but more on that later.
In the intervening years we have had numerous reports commissioned and delivered, and I have written plenty of blog posts. I don’t plan to revisit these here, but instead refer you to some of these posts and some of the most recent reports, which listed at the bottom of this page.
Something else also happened in those years. I watched the reef succumb to unprecedented levels of coral disease, and I watched as algae grew out of control – including lyngbya (more on that here). One of our coral health researchers, Dr Charlotte Page says of the disease affecting our reef, ‘this event is comparable to some of the most severe coral disease outbreaks recorded to date …’ and ‘In December 2020 and April 2021, we observed 60% of surveyed Montiporid coral colonies with signs of disease, a prevalence in line with the most severe coral disease outbreaks recorded to date worldwide’ (my emphasis).
Annual rainfall from 2016 to 2023, Norfolk Island
In 2022, we almost doubled our average annual rainfall. Tanks filled, as did the bores when the water table was replenished. Absolutely, this was great for the residents who are self-sufficient for their water supplies and are very aware of the cycles of flood and drought, but the water run-off into our bays left increased amounts of corals suffering from disease. Fish species became scarcer, algae grew. I’d come back from my regular swims feeling sad and demoralised at what I was seeing.
By November 2023, the island was once again experiencing a drought. Clearly there will be other factors at play, for example the bays became a no-take zone for echinoderms (sea urchins and sea cucumbers) about a year ago, but, anecdotally, I began seeing new species of fish never recorded here before, and increased numbers of fish more generally. Sea urchins and, to a lesser extent, sea cucumber numbers seemed to bounce back. And despite the looming bleaching event predicted for March 2024, the corals began to look healthier. We did get some bleaching, but certainly not as much as was feared.
Since March, we’ve had a wonderful boom in juvenile fish.
The man-made channel to Emily Bay, created in 1789 when the British first settled the island, and the main way for overland fresh water to enter the lagoons, was plugged with sand. I was holding my breath hoping that any rain we got would be gentle enough not to cause a torrent and displace it.
On 19 July 2024, having had a small amount of rain in the previous 24 hours, I went down to specifically check on the plug. There was a puddle there, but it was intact. In the next 24 hours we had 28.6 mm by which time the sand plug was well and truly breached. A stream of foul-smelling water was entering the bay, leaving a foamy slick across the sands. Children were playing in the stream and tourists were swimming. There had been no public health notices from NIRC regarding the water quality.
I confess to being puzzled because 28.6 mm, while being a respectable amount, was probably not enough to cause the stream of water I was seeing. What else was happening, I wondered. It is worth noting here that on 6, 10 and 24 June we had 31.8 mm, 28 mm and 29 mm, respectively and the sand plug remained in place. I wasn’t to get the answer to my question for a couple more days.
That Saturday afternoon I contacted Biotec and requested a water test be done for E.coli and Enterococci levels (the latter being the best indicator of water health). This was done early on Sunday morning, 24 hours after the breach of the sand plug. I also alerted Marine Parks and the coral reef researchers to let them know what had happened. They had been unaware of any issue.
There was still no public health notice being broadcast on any media by NIRC.
Screenshot of NIRC’s public health update, 9am, 22 July 2024, taken from the NIRC Facebook account
On Monday 22 July, 48 hours after the sand plug breached, NIRC put out a public health warning stating that pollution was likely at the Emily Bay outlet. Meanwhile, I received a few messages from other swimmers, who, like me had been concerned about water quality. I was also asked if I knew anything about Watermill Dam, because it was looking rather empty, having previously been full on the Friday before.
That morning, I also received Biotec’s report and the results were as I had suspected. Devastating. To simplify things, I will just give you the Enterococci level results. It was 400,000 CFU/100 mL (or 400,000 MPN/100 mL if you prefer).
If you recall from above, anything over 500 MPN/100 mL is considered unsafe for swimming and, according to NIRC’s website requires a red alert. And according to the Australian Government’s Guidelines for Managing Risks in Recreational Water (on p. 59), a red alert requires the following action:
Monitoring indicates unacceptable risks to recreational users to an extent requiring the local authority and health authorities to warn the public that the water body is considered to be unsuitable for primary and secondary contact.
Except NIRC hadn’t acted for more than 48 hours from the time the channel’s sand plug was breached.
The Seine, the Olympics and that triathlon
Shortly after this occurred, we were all glued to the first week of the Olympics being held in Paris. In particular, my attention was drawn to the triathlon event and the debate surrounding the water quality in the Seine. In previous articles I have compared our post-rainfall lagoonal water in Emily Bay to the Ganges, but how did it compare to the Seine, I wondered.
So I found out.
You can go to this page and translate it if you wish, but to make it easy, here is a copy of the image giving the Enterococci levels at various spots along the Seine. As you can see from the graph, the CFU reached just over 800 CFU/100 mL. Concerned that these levels were too high, the Olympic organisers were going to cancel! If you recall, Emily Bay was 400,000 CFU/100 mL!
Enterococci concentration level in CFU / 100 mL in the Seine during the Paris Olympics
Watermill Dam fails
So what happened at the dam and what part did it play in the breaching of the sand plug?
The next part of the puzzle is pieced together from conversations with others, both in positions of authority and residents. It seems that a pipe at the dam failed on the Friday evening, at the worst possible time with everyone knocking off for the weekend. We can speculate that the failure in the pipe was due to a lack of regular maintenance.
The biggest risk to the dam emptying was that the acid sulphate soils, which are benign and completely safe when covered in water, would be exposed to air and begin the oxygenation process. This is where the metal sulphides react with oxygen to produce sulphuric acid. The downstream effects of this could have been disastrous for the environment.
Fortunately, the leak in the dam was arrested with a few centimetres to spare, and the acid sulphate soils remained safely covered. But we came very close to an environmental disaster that weekend. I have been reassured that procedures will be put in place to prevent a similar accident from occurring and a disaster and/or emergency management plan formulated in the event one does.
The budget
I completely understand the costs associated with effectively cleaning up our waterways; and I appreciate that staff at NIRC and the Department of Infrastructure are working to tight budgets. What I find difficult to come to terms with is:
the lack of health warnings for 48 hours, which directly compromised recreational users’ health
the apparent lack of routine maintenance taking place at the dam
and the lack of any communication until the Monday morning with other government departments.
A promptly enacted disaster/emergency management plan involving all members of the Water Quality Committee, ostensibly a group of people representing all government agencies on-island, should have been the very first thing that occurred.
I also find it difficult to reconcile the lack of urgent action by the Commonwealth government to budget for a solution to these ongoing water quality issues, which I have been raising for four years, and many before me have been raising for decades. If we have no reef, we have no World Heritage property of Kingston and Arthur’s Vale. The reef is our buffer against what can be substantial seas that crash into the coast there. And then there is the important biodiversity of that reef, where it is thought that at least 30 per cent of our corals are unique to Norfolk Island and are, as yet, undescribed.
I appreciate a few people saying that the water quality has always been suspect after rainfall and it never did them any harm in the past, but I’m not sure that is a reason to not provide public health information on these startlingly high Enterococci readings. If the public have the information, they can make their own judgement about whether to swim or not. If it isn’t safe for Olympian triathletes, then it certainly isn’t safe for children, the elderly, tourists and those who are immune compromised.
As for the fish and corals and all the other plants and critters in our unique and very special coral reef ecoystem, they have no say about what we pour into the bays.
The wetlands
I always find it best to end on a positive note if I can, and one real positive for me in all this is that the reeds in the wetlands on the Kingston Common did an amazing job of holding back the sediment – which along with high levels of nutrients is another enemy of corals. I have attached photos taken before the reeds were doing their job and on 20 July 2024 when they most definitely are. As you can see, the water, while polluted with faecal matter and high in nutrients such as phosphates and nitrates, is running clear. The only signs to alert the unaware to the pollution on 20 July 2024 was the beach scum and that putrid smell.
Heavily laden with sediment, and polluted, 23 July 2022
Sediment free (but still polluted) water, courtesy of the reeds on Kingston Common, 20 July 2024
Further reading
Best read in this order. Apologies for the amount of reading!
Blog posts
We can’t say we weren’t warned https://www.norfolkislandreef.com.au/out-on-a-swim/we-cant-say-we-werent-warned
Playing the long game on Norfolk Island’s reef https://www.norfolkislandreef.com.au/out-on-a-swim/playing-the-long-game-norfolk-islands-coral-reef-and-lagoons
The state of play on Norfolk Island’s reef https://www.norfolkislandreef.com.au/out-on-a-swim/the-state-of-play-on-norfolk-islands-reef
Come on in, the water’s fine https://www.norfolkislandreef.com.au/out-on-a-swim/come-on-in-the-waters-fine
Norfolk Island’s forgotten reef needs help https://www.norfolkislandreef.com.au/out-on-a-swim/norfolk-islands-forgotten-reef-needs-help
A year in review – 2022 on Norfolk Island’s reef https://www.norfolkislandreef.com.au/out-on-a-swim/a-year-in-review-2022-on-norfolk-islands-reef
Draining the swamp https://www.norfolkislandreef.com.au/out-on-a-swim/draining-the-swamp
Tiptoeing through the government silos https://www.norfolkislandreef.com.au/out-on-a-swim/tiptoeing-through-the-government-silos
Bubble and fizz – a quick guide to coral reef chemistry https://www.norfolkislandreef.com.au/out-on-a-swim/bubble-and-fizz-a-quick-guide-to-coral-reef-chemistry
The clock is ticking for Norfolk Island’s reef https://www.norfolkislandreef.com.au/out-on-a-swim/the-clock-is-ticking-for-norfolk-islands-reef
For the sake of our grandchildren https://www.norfolkislandreef.com.au/out-on-a-swim/for-the-sake-of-our-grandchildren
The spatiotemporal dynamics of a coral disease https://www.norfolkislandreef.com.au/out-on-a-swim/the-spatiotemporal-dynamics-of-a-coral-disease
The journey from coral reef to rubble https://www.norfolkislandreef.com.au/out-on-a-swim/the-journey-from-coral-reef-to-rubble
Combine bacteria, fungi, and maybe a sponge = one toxic mess https://www.norfolkislandreef.com.au/out-on-a-swim/combine-bacteria-fungi-and-maybe-a-sponge-one-toxic-mess
Norfolk Island Reef’s autopsy reports https://www.norfolkislandreef.com.au/out-on-a-swim/norfolk-island-reefs-autopsy-reports
Reports
Note: Some of these links are to the old NIRC website and as such may appear as unsafe links. They are all fine to use.
Ainsworth, T., Ricci, F., Leggat, W., Gastone, T., Williamson, J., Heron, S., Raolt, V., Page, C., Bergman, J., Vuleta, S. (2022a). Preliminary Report assessing Norfolk Island Lagoonal Reef Ecosystem Health. Marine Parks and Island Parks Branch, Parks Australia.
Ainsworth, T.D., Heron, S.F., Lantz C. and Leggat, W. Fordyce, A., Page, C., Gardiner, S., Caldwell, J., Moriarty, T. (2022b). Norfolk Island lagoonal reef ecosystem health assessment 2020–2021.
Bligh Tanner (2020). Improving the Water Quality of Emily Bay, Norfolk Island. Parks Australia.
Golding L.A., Currie S., Donaldson D., Greenwood D., Lamontagne S., Tavener N., Taylor N., and Vanderzalm J. (2023). Norfolk Island Water Resource Assessment. Marine Water Quality – Year 1 of water quality monitoring and interim site-specific guideline values. A report from the CSIRO Norfolk Island Water Resource Assessment Team to the Australian Government.
Hoffman, G.T., Broyd, D., Talbot, S., O’Donovan, G., Drydale, M., Teis, M., and Roderick, I. (2020, November 15). Norfolk Island Regional Council Independent Governance and Financial Audit. Report for Commonwealth Department of Infrastructure, Transport, Regional Development and Communications, 5, 14, 65–68.
Leggat, W., Gaston, T., Page, C., Ainsworth, T. (2023). Reef Health Survey for Emily and Slaughter Bay, Norfolk Island (January 2022 – April 2023). Australian Marine Parks.
Vanderzalm, J., Currie, S., Smith, W., Metcalfe, S., Taylor, N., Ahmed, W. (2024). Microbial source tracking of fecal pollution to coral reef lagoons of Norfolk Island, Australia. Science of The Total Environment, 912.
Wilson, P.J. (2017). Water Quality in the KAVHA Catchment. Norfolk Island Regional Council.
Wilson, P.J. (2022, April 14). Are you planning an upgrade to your septic tank: media release. Norfolk Island Regional Council.
More detail on NIRC’s testing regime
The water quality testing for Enterococci, E. coli etc. was formerly undertaken by a qualified local contractor, Biotec, using traditional individualised testing methods. The results were reported as CFU/100 mL (colony forming units per 100 milliliters). The number of CFUs is determined by the number of visible colonies of bacteria grown on a plate over a fixed period, usually 24 hours. You can click on the image to enlarge the media release.
NIRC switched to testing the water with the Quanti-Tray 2000 test kits, which are considered to be a more efficient and cost-effective way to detect bacterial contamination compared to traditional methods. They are used widely by businesses and government departments. Quanti-Tray test kits are semi-automated and use the Most Probable Number (MPN) technique to quantify bacteria such as Enterococci, total coliforms and E. coli in water samples. The MPU technique measures the growth of bacteria statistically rather than visually. For our purposes, the MPU is considered to be interchangeable with a CFU, ergo, 500 MPU/100 mL is the same as 500 CFU/100 mL
Each Quanti-Tray 2000 test kit costs around $15 and will count up to 2419 CFU/100 mL, with any results over 500 CFU/100 mL considered to be a health hazard. Helpfully, NIRC has a page on the website that discusses the water quality testing, and provides a table of the levels. For Enterococci, anything above 500 MPN/100 ml is described as ‘bad’ and given a red alert.
Traditional, individualised water testing for faecal contamination costs a great deal more and probably gives more detail than is necessary for NIRC’s purposes; although, having said that, it does give you a better idea of the real severity of the problem when you get results for Enterococci of 900,000 CFU/100 mL as we did back in July 2020.
Quanti-Tray kits are approved by NATA, an organisation that accredits laboratories so that, to quote their website, they can give ‘consumers [in this case, NIRC] the assurance they need to make safe, healthy, reliable choices’. For laboratories, it says ‘When you choose to become NATA accredited, you can be sure of a number of competitive advantages for your business.’
NATA provides quality assurance by accrediting laboratories. Laboratories are charged a fee and the consumer is reassured that any testing done will be standardised and done to the highest standards.