Opinion

Merimbula Ocean Outfall – is that really our best option?

Ian Campbell26 April 2019
The poo pipe that once did extend into the sea was destroyed in the 1970's, ever since the remains of the pipeline have dumped excess treated effluent on to Pambula - Merimbula beach. Photo: Brent Occleshaw for BVSC.

The poo pipe that once did extend into the sea was destroyed in the 1970s, ever since the remains of the pipeline have dumped excess treated effluent on to Pambula – Merimbula beach. Photo: Brent Occleshaw for BVSC.

The proposed ocean outfall for Merimbula Bay has been on my mind, perhaps a little too much, but at the same time, I feel like this is a big deal.

It wasn’t on my mind however when I walked into Bemboka Pie Shop to buy a caramel slice and a lamington for a ‘meeting’ I was headed into. I wasn’t really sure what we’d talk about at this ‘meeting’ but I had a sense it would be challenging – baked treats, I thought, would be good for all concerned.

What struck me as I stood at the till paying for my goodies was the full page of signatures on a petition resting on the countertop.

“We the undersigned do NOT want a deep ocean outfall for our waste management,” the petition read.

“We would prefer the tertiary treated effluent to be used as a bi-product for making wetlands to attract birds. An irrigation system to farmers and or storage for times of drought. Similar to what the Byron Bay Shire has been doing for the last 10 years.”

The petition was launched on behalf of the Merimbula Sailboard Club by local abalone diver John Smythe, who is also a member of Council’s ocean outfall Community Working Group, and Marianne Kambouridis, the convenor of the Merimbula/Pambula Wastewater Alternatives group.

The fact that a petition at Bemboka, a village so far from the sea, had managed to attract a long list of signatures struck me.

But then again, Bemboka’s poo and wee does end up at the Merimbula Sewage Treatment Plant (STP) in the back of a truck after a septic pump-out.

I don’t think Bembokans realise their five-yearly pump outs end up in Merimbula STP. In fact, all of the shire’s poo trucks dump at Merimbula. More so I think the strength of the response to the petition at Bemboka was more about the treasured Bega Valley environment and the commonsense of reusing wastewater.

These are values Bega Valley Shire Council says it holds dear.

“Our region’s reputation is based on our unspoilt natural environment and I am absolutely determined to safeguard our precious environment,” Mayor Kristy McBain said last month.

Being able to action those values and put resources behind them is always the challenge, which might explain why the region finds itself with a proposal that is at least six years old to build a 5 km pipeline into Merimbula Bay to discharge treated effluent.

There is much about Council’s plan that, to my mind, is compelling.

The existing beach-face outfall half way along Pambula – Merimbula Beach is simply unacceptable. When I first arrived in the Bega Valley 23 years ago I had to find this thing to believe it. Following a big storm in the seventies, the poo pipe that once did extend into the sea was destroyed. Ever since the remains of the pipeline have dumped excess treated effluent on to the sand.

Dunal exfiltration ponds currently used by BVSC impact groundwater and Aboriginal heritage. Photo: Brent Occleshaw for BVSC.

Dunal exfiltration ponds currently used by BVSC impact groundwater and Aboriginal heritage. Photo: Brent Occleshaw for BVSC.

The other arm to disposing of the excess is the dunal ex-filtration ponds in the sand dunes immediately behind the beach-face outfall. Again, simply unacceptable. The treated effluent ends up in groundwater and finds its way into Merimbula Lake posing a threat to the town’s famous oyster leases.

On top of that, these sand dunes hold great Aboriginal significance.

At a Council media briefing about the ocean outfall project, local elders BJ Cruse and Graham Moore talked about the area being a burial site, with at least nine bodies.

“There is a high possibility of finding other remains,” Mr Moore explained.

“This was a place of tribal huts and was a consistent place of camping and was still in use by Aboriginal people at the time of Bass and Flinders.”

We need to stop dumping our ‘shit’ in this place.

For all those reasons, in 2009 the NSW Environment Protection Authority (EPA) instructed Council to find better disposal methods but for the last 10 years has given Council a period of grace but not the big money to do anything.

The $30 (ish) million outfall project has however been listed as ‘State Significance Infrastructure’ implying that NSW Government money will be there when the project is ready. That day is getting closer with the Environmental Impact Statement due in May next year followed by project approval five months later.

A secondary part of the project is an upgrade to the effluent treatment process and infrastructure that allows for a greater potential for reuse.

Pambula Merimbula Golf Club has 1000 sprinklers all irrigating from the Merimbula STP. Photo: BVSC

Pambula Merimbula Golf Club has 1000 sprinklers all irrigating from the Merimbula STP. Photo: BVSC

Council currently reuses about a quarter of the recycled water from Merimbula STP for irrigation at Pambula Merimbula Golf Club and Oaklands Farm.

“We’ve been distributing recycled water to the Pambula Merimbula Golf Club for over 40 years and irrigation to Oaklands began in 2013,” Council says.

“The amount of reuse varies according to rainfall and in those years of high rainfall, these sites need less irrigation.

“As much as we’d like to be able to, it is just not possible to reuse all of the treated wastewater because of our climate, existing land use and topography,” Council says.

In short, when it’s raining – we need a place to put this stuff.

On top of liquid reuse, “Merimbula STP processes beneficial bio-solids from Cobargo, Wolumla, Candelo, Kalaru, Merimbula and Pambula.”

‘Bio-solids have high nutrient value and can be used as a nutrient-rich organic soil conditioner on farms,” Council says.

“Bio-solids used to go to landfill but we are now supplying a contractor, who is working with local farms and the NSW EPA to reuse organic bio-solids.”

However, the kind of 100% reuse options suggested as an alternative to the ocean outfall have been rejected by Council as being unsuitable. Indeed, some Bega Valley Shire Councilors have suggested the EPA wouldn’t allow wetlands and the like in this region.

The reasons given come from qualified, experienced Council staff and seem sound, but essentially go back a decade.

The one thought I haven’t been able to resolve is that in these times of a changing climate, dumping what is already close to being fresh water into the ocean is our best option. It might have been in 2009 when this issue come to a head but in 2019?

In the almost ten years this project has remained unfunded by both sides of politics at a State level. Bega Valley Shire Council and the community more broadly has embraced a range of bold environmental initiatives – FOGO is the most recent and obvious.

Is something equally as bold possible with the shire’s waste water?

The Bega Valley has 10 ocean/river/beach face outfalls all discharging into an environment we treasure, the fact that after 10 years the NSW Government hasn’t yet funded the Merimbula STP upgrade presents an opportunity to do something different.

Cake anyone? I know a great little bakery!

Do you think the decision to build an ocean outfall at Merimbula should be revisited or are we too far down the track?

What's Your Opinion?

62 Responses to Merimbula Ocean Outfall – is that really our best option?

Peter Bond Peter Bond 5:54 pm 01 May 19

There is a water shortage. Pump or truck the water to central Australia.

Sydney sewerage is being sold profitably, so why not?

David Porter David Porter 10:12 pm 30 Apr 19

This current council is not interested in community consultation, it’s simply how do we bully ratepayers into accepting our position, for example, the bike path in Tathra, 3 options and the residents say we don’t want option 1 but the council claims to have consulted the community and yet goes with whAt they want, screw the ratepayers, example 2 the great FOGO scam, council says 27% of our garbage by weight is fogo, now that equates to 5% by volume, but despite complaints our red bin garbage service has been reduced by 50%, rubbish is one of the fundamental responsibilities of council yet the smelly garbage is piling up, we have NEVER EVER seen a rat or cockroach in our house until this slovenly council stopped performing their sworn duty. I could go on with examples all night, e-zones, lot sizes, property access, the disgraceful tourism tender sham and of course this wastewater deal, can all the people signing the contract remember the names in council and change them all next election so we can have some councillors working for the benefit of the RATEPAYERS!

Connie Crawford Connie Crawford 4:50 pm 28 Apr 19

Told you before - No amount of conversing with the Shire is going to change the out come - Outfall is it... it’s all just PR work!! 🥵

John Richardson John Richardson 10:26 am 27 Apr 19

The Bega Valley Shire Residents & Ratepayers Association (BVSRRA) believes that council is determined to pursue the ocean outfall pipeline, regardless of the merits of alternate, more responsible environmental options, such as exfiltration & re-use.

We believe that if council was seriously interested in pursuing the “best” solution for the community (environment), then it would be doing its utmost to ensure that all possible alternatives were fully examined in an open & transparent fashion, instead of working assiduously to dismiss alternate options.

For those who would dismiss the exfiltration/reuse option, please be aware that it was council’s original Focus Group that recommended that should funding by State and Federal Governments not be forthcoming, then council should “consider an effluent management strategy involving a Shallow Dunal Exfiltration system for disposal, additional treatment plant upgrades including nitrogen reduction & the expansion of effluent irrigation on the Pambula Merimbula Golf Club”.

Along the line, council has insisted (falsely) that the pipeline option is the only option & that that decision was taken by the Environment Protection Agency (EPA).

Council, including Mayor Kristy McBain, has recently made much of the need to close the exfiltration works in the dunes adjacent to the beach behind the current beach outfall pipe, on the basis that there is a need to respect Aboriginal artefacts & burial sites, & to prevent the ongoing seepage of sewage pollution into the nearby lakes system.

At the same time, in response to community concerns voiced over the proposed outfall pipeline, council’s general manager, Leanne Barnes, tried to downplay its significance by saying that it would only be used as a “last resort”, before going-on to make the ridiculous claim that council would “love to be able to do 100% reuse”.

Notwithstanding the smoke & mirrors being used by council to justify its actions & confuse the community, the community needs to recognise that if the dunal exfiltration system is shut-down & the reuse system remains as it is, then 70% of all sewage effluent will travel into the ocean 5kms offshore from Merimbula/Pambula beach.

Since most of the key decisions that council is blindly pursuing were made almost a decade ago, this country has come to better understand the real value of water resources, as well as the sheer stupidity & irresponsibility of despoiling our environment with pollutants simply because we are too ignorant & lazy to seriously examine the alternatives. John Richardson, Secretary/Treasurer, BVSRRA.

    Grant Webster Grant Webster 7:26 pm 27 Apr 19

    Given that all things are possible if you have the money to pay for it, I wonder what the BVSRRA would have to say about BVSC spending an extra few $M of rate payers' money on "the “best” solution for the community (environment)" given that they scream blue murder every time BVSC spend ten bucks on anything. SCT spent $4M on tourism promotion in a decade and BVSRRA banged on about it for years - even though tourism expenditure increased $19M in one year. Fraser was on the radio a while back arguing that SCT was a waste of money because "the tourists are coming here in droves anyway". Um yeah. I wonder why they're coming in droves Fraser. My experience of BVSRRA is they love an argument regardless of how baseless their concerns are or how incoherent their arguments are. They have a membership base of 75 people - out of 33,000 shire residents.

    John Richardson John Richardson 5:32 pm 28 Apr 19

    Grant Webster Hi Grant. I can see you haven't lost your capacity to twist the facts to suit your agenda. For the record (& not for the first time) our bitch with council's spending of ratepayers funds in support of the tourism industry was not about the expenditure itself, but rather that there was no oversight of that expenditure & no accounting for it, not to lose sight of the fact that there was little to show in the way of benefits). As for your observation about Fraser's comments, her was referring to unconscionable waste of money being frittered-away on the expansion of the airport in pursuit of an alleged 600,000 increase of inbound tourist number when we already attract upwards of 1M every year without that. The BVSRRA has always supported tourism but it has also argue that the tourism strategy should be targetting his value low volume tourism rather than the low value high volume approach being pursued by Constance & his ilk; even though they know & understand that we do not have the infrastructure to support those numbers. Coiming back to the issue at hand, given that council is already talking about spending $30M + for the sewage outfall pipeline proposal, we think that there is ample room to examine alternate proposals that might well cost less than that. Of course, if you aren't even interested in exploring that possibility, you really have no point to make. BTW Grant, why are you so positive about outfall proposal or is it that your real issue is with the BVSRRA?

    Grant Webster Grant Webster 6:10 pm 28 Apr 19

    1) Fraser was talking about SCT funding on the radio when he said "tourists are coming here in droves anyway". 2) I don't know anything about the airport expansion and have never commented about it. 3) The tourism strategy, since 2008, has targeted "well heeled experience seekers" (high value, low volume) through the Coastal Wilderness branding and partnerships with entities such as Paddy Pallin. "Constance and his ilk" are typical Liberals - 2D minds in a 3D world. 4) BVSC has already examined several alternative proposals in consultation with the community and qualified experts. 5) It's not that I am "positive about the outfall proposal", I just see an endless stream of uninformed comment and misinformation about the project. Hysteria has overwhelmed any chance of an adult conversation and reality has gone out the window. 6) BVSRRA always has lots to say and nothing to contribute.

    John Richardson John Richardson 5:32 pm 30 Apr 19

    Grant Webster Thanks Grant. Would you like us to add you to our distribution list so you can be better informed?

    Grant Webster Grant Webster 5:33 pm 30 Apr 19

    Sure John.

Fraser Buchanan Fraser Buchanan 10:07 am 27 Apr 19

The proposed treatment upgrades are limited to some phosphorous reduction and UV treatment to kill bacteria and pathogens, there is no additional proposal to remove nitrogen....we are dealing with a product that has many chemicals, micro plastics, medicines and endocrine disruptors and high levels of nutrient, a cocktail of nasties to be pumped into our bay for perpetuity something so archaic and destroying our marine environment in the process........back nearly a decade ago when the council carried out there options studies they looked at the idea of treating the effluent to the very highest standard, to a standard that would remove all of these nasties and provide a product that would be drinkable and could be returned to the Yellow Pinch dam water supply, this at the time was costed and was marginally dearer than building a mega outfall pipe and just doing minor treatment upgrades, it was seen by the then focus group as unacceptable because they didn't believe the public would accept having recycled effluent in their water supply.... perhaps true....but if you take the cost of running a pipeline out to the dam out of the equation then the project would be way cheaper than the outfall option and you have a product that is literally best quality and drinkable and of no harm to the environment......and to deal with excess water an exfiltration trench also costed at the time could be built away from the existing pond area's at a minimal additional cost addressing any Aboriginal heritage issues by Xray scanning the sand dunes beforehand.....additional reuse for the Golf course and farmers desperate for water given as a priority......it has got to be a better outcome.

Elaine Cozens Elaine Cozens 9:47 pm 26 Apr 19

Just do the wise thing council it is clear enough to residents

Dörte Planert Dörte Planert 6:39 pm 26 Apr 19

So much money spent on an inferior option, which is not a real solution. It can't be the best option. If the water is clean enough, it can be reused for e.g. irrigation. If not, it should not end up in our oceans either.

Anthony Grant Anthony Grant 5:45 pm 26 Apr 19

Treatment Plants ....

👁👁

Are the ONLY WAY forward, OTHERWISE your just increasing the pipe pumping SEWAGE and RUBBISH INTO OUR OCEANS which is NOT OK ... 😡😡😡😡😡

Elly Bloch Elly Bloch 5:09 pm 26 Apr 19

No do not approve. X

Grant Webster Grant Webster 2:09 pm 26 Apr 19

This has been a 10 year process and BVSC have considered every alternative people are now proposing and have done so in consultation with the community and qualified experts. It's all to simple to just say "we should pump it out on to farms or into dams" without understanding the full implications of those alternatives.

    Stephen Kambouridis Stephen Kambouridis 2:14 pm 26 Apr 19

    Sounds like Tony' s logic. Trust us. Coal is the way to go.

    Marianne Kambouridis Marianne Kambouridis 2:35 pm 26 Apr 19

    And 10 years ago, we had fewer options. Today we can find examples of serious reuse options, crops, wetlands, eco-forests and irrigation systems with the use of plastic media trickling filters. We have three engineering companies who all state without at doubt, that an ocean outfall is madness. While you are at it Grant Webster, have a look at Clean Ocean Foundation, as they have an outfall data base with some very disturbing facts. Facts that councils do NOT want us to be aware of.

    Dörte Planert Dörte Planert 4:34 pm 27 Apr 19

    Germany is transforming/recycling its water back into the system, running it through 5x filtration e.g. natural rock pools and weed ponds, making it fully drinkable. Perhaps Australia needs to look at such options, instead of only looking for the cheapest solution. Berlin does not even need to chlorinate because of natural filtration, only uses UV to kill bacteria.

    Grant Webster Grant Webster 6:34 pm 27 Apr 19

    With all due respect Marianne, "crops, wetlands, eco-forests and irrigation systems with the use of plastic media trickling filters" were not invented in the last 10 years. I suggest you draft a comprehensive proposal for an alternative system complete with feasibility studies, environmental impact studies, detailed plans and engineering and a budget to present to council. Everything you have proposed is possible, but is it viable at this location when all the variables are taken into account? I heard you interviewed on Sapphire FM a while back and you said you accept the fact that an outfall is a necessary part of any system we have. You even went so far as to suggest we could just keep dumping it on the beach instead of taking it further out. No thanks. Who are the "three engineering companies who all state without at doubt, that an ocean outfall is madness"? Peace.

    Marianne Kambouridis Marianne Kambouridis 7:05 pm 27 Apr 19

    Grant Webster Our council are the ones who should be undertaking a feasibility study on current options. The three engineering compainies are, The Water and Carbon Group. David Flegilman's TYR treatment and reuse group and The Global Water Institute. I also have Michael Bingham from Byron Bay Shire council who went through similar community opposition for their STP who has been a goldmine of information and support for us. Peace

Rob Tweedie Rob Tweedie 10:39 am 26 Apr 19

im sure everyone including the council would like to re-use and irrigate, not let the product go out to sea but is there an actual alternative atm, is someone putting their hand up for the product. We cant just say lets build a pipe and pump it to Cathcart for instance unless we come up with a plan to present to council where someone is willing to take and distribute the excess product. It seems atm no one has that plan or costings. I hate the thought of the outfall but i dont personally have the answer to an alternative.

    Grant Webster Grant Webster 2:09 pm 26 Apr 19

    Exactly Rob. This has been a 10 year process and BVSC have considered every alternative people are now proposing and have done so in consultation with the community and qualified experts. It's all to simple to just say "we should pump it out on to farms or into dams" without understanding the full implications of each alternative.

    Marianne Kambouridis Marianne Kambouridis 4:32 pm 26 Apr 19

    yes we do have a hand up. Stuart Whitby has a dam that can be filled and irrigated from. This dam can store 40ML and can then be used as a gravity run irrigation system to other farms. There is another farmer who wishes to remain unkown for the moment who is also after this resource. As more farmers aquire this knowledge, we will have more options for storage and irrigation. The area at Lochiel has been recommended by another wastewater engineer who is in Byron Bay and agrees that Lochiel is similar to Maleny with its undulating land and pockets for dams.

    Marianne Kambouridis Marianne Kambouridis 4:39 pm 26 Apr 19

    Grant Webster This has been going on for 10 years and every alternative has been 'looked' at but not in a great deal of detail. The ocean outfall will 'fix' our sewage issues in one hit, so to speak. However, when one looks carefully into the alternatives that are actually being done right now, one can only wonder why our shire, given the large rural areas surrounding us, will not reconsider adopting a similar approach to Maleny ( Sunshine Coast Council). Looking at Dr. Keith Bolton and his Hemp crops grown on effluent, or the numerous benefits to a community when a wetland/eco-forest is constructed; tourism, carbon sink, green spaces, research and study oportunities for schools, reuse of a once thought of 'waste' product, increase in birdlife......The research done on the deep ocean outfall has been huge! We only ask that the same energy be spent on contacting farmers, employing engineers from The Water And Carbon Group, or TYR treatment and reuse and have another study undertaken on using land at Lochiel which will not impact on the Oysters.

    Dörte Planert Dörte Planert 4:36 pm 27 Apr 19

    Germany is transforming/recycling its water back into the system, running it through 5x filtration e.g. natural rock pools and weed ponds, making it fully drinkable. Perhaps Australia needs to look at such options, instead of only looking for the cheapest solution. Berlin does not even need to chlorinate because of natural filtration, only uses UV to kill bacteria.

    Fraser Buchanan Fraser Buchanan 5:18 pm 27 Apr 19

    Grant Webster certain options were well considered back between 2009-12 but not all options were thoroughly considered, there have been other option put on the table since that should be properly assessed, did you not read my suggestion about treating it to potable standard?

    Grant Webster Grant Webster 6:53 pm 27 Apr 19

    Fraser Buchanan I personally think treating the water to potable standard, or close enough to add it back to our storage system, is the ideal solution but we'd face enormous cultural resistance within the community - the urk factor - people just can't get past the deeply ingrained belief that it is somehow dangerous. A bit like the waterless compost toilets I've been promoting for 33 years - people just can't get their heads around the fact they don't smell - cultural resistance based on a fallacy. Here's me talking about waterless (get it - 'waterless') compost toilet systems (CTS) in a discussion about how to reduce effluent volumes. Just let that sink in a minute. We take a handful of waste and turn it into a whole bucket of waste by flushing it down a toilet. 30% of what we are dealing with here comes from that single stupid habit we have been conditioned to. Thankfully and finally CTS are being accepted into the mainstream. I've been 33 years in this space. Treat the waste and put it in Yellow Pinch dam.

    Grant Webster Grant Webster 7:01 pm 27 Apr 19

    Marianne Kambouridis as I said above, everything you have proposed is possible, but possibly not feasible. When you say "every alternative has been 'looked' at but not in a great deal of detail", how much detail are you talking about? BVSC engaged highly qualified consultants with a comprehensive track record in the field who I would expect to have looked in detail at each alternative before presenting their report - see Fact Sheets #1 - 16.

    Marianne Kambouridis Marianne Kambouridis 7:08 pm 27 Apr 19

    Fact sheets do cover general information however when you compare this to the research, studies etc on the ocean outfall, you realise that these fact sheets appear as token gestures.

    Marianne Kambouridis Marianne Kambouridis 7:09 pm 27 Apr 19

    Look at Emerald beach to see how the community there stopped a proposed outfall.

    Marianne Kambouridis Marianne Kambouridis 7:12 pm 27 Apr 19

    There is only ONE reason our council have dictated to the focus group as to why we MUST have an outfall ($30 M) and that is the 30 year plan of mega development. This place will be like the Gold Coast-guarenteed! There is always some bean counter out there, employed by local government to stipulate what has to be done. We are just going through the motions. The whole of Mirador was planned from way back in 1989!

    Grant Webster Grant Webster 7:34 pm 27 Apr 19

    Marianne Kambouridis on the contrary, I think it is the BVSC's job to plan for growth and I'd be disappointed if they didn't. It doesn't necessarily mean "mega development". I think it would be far worse not to plan for growth, thereby setting us up for a crisis management scenario when and if the population outgrows the current system. BVSC can control the extent and types of development they allow, but population growth is something we have to prepare for - especially if everyone continues to insist on flushing toilets. 🙃

    Fraser Buchanan Fraser Buchanan 8:28 pm 27 Apr 19

    Grant Webster I am with you about the composting toilets and probably about the publics perception regarding recycled effluent going back into the water supply......but you would have to consider expending $30-40million to run a mega pipe out into the bay to dispose of effluent that is only treated a bit better than the current quality with (phosphorous reduction and UV treatment) as against expending a lot of that money on treating the effluent to a drinkable standard where you have a product that is not anymore harmful than rain itself and therefore disposal is minimal concern, it could be either used by expanding the reuse on the golf course or extending the pipeline out to farms at Lochiel or going with the original focus groups second preference of developing a shallow dunal exfiltration 400m trench to the north of where the current exfiltration ponds are, the environmental concerns for all options are minimalised by the fact the effluent is treated to a potable standard...it could be the existing outfall pipe is retained

    Fraser Buchanan Fraser Buchanan 8:39 pm 27 Apr 19

    The Golf club have floated the idea of putting a massive holding capacity at the top of their course in the bush and developing and converting their other dams into effluent ponds, soaks, reed beds, etc linked together meandering down through the course as an extra polishing process with the effluent finishing back at the treatment works ready for distribution to reuse users and or disposal through exfiltration trench....what a great concept another concept that has never been given any consideration by the council or the previous focus group.. amazing how things can change and evolve over time..

    Grant Webster Grant Webster 9:51 pm 27 Apr 19

    Fraser Buchanan it sounds simple. I've looked at UV for greywater and turbidity is an issue. Better to use a wetland/reedbed, but that's not always possible and comes at an expense - both money and space. There's lots and lots and lots of variables at play (and interplay) and this Facebook discussion can, at best, scratch the surface. The council has investigated every alternative that this forum has proposed and is investigating lots of alternatives for reuse - PMGC, Oaklands, Pambula Sports Complex. Your whole argument is full of holes mate. You're either suggesting something they've already done or something that relies on it never raining. In case you don't know, the current committee is weighing up how much of the budget goes to treatment and how much to the outfall pipe. Better treatment = shorter pipe. Most of the impact on the ocean environment from effluent is from nitrogen in ammonia - hence the group is proposing allocating money for a denitrification unit as part of the STP. BUT the point is ... you need a relief valve in every system - that is what the outfall is. After that the trick is to reduce the volume that goes out that valve - and that's an ongoing job.

    Fraser Buchanan Fraser Buchanan 10:05 pm 27 Apr 19

    Grant Webster you think you you know what you are talking about, I am on the working group and each of those proposal haven't been properly considered by council or the consultants, so get you facts right

    Stephen Kambouridis Stephen Kambouridis 3:30 pm 28 Apr 19

    Grant Webster . Turn up at the next public meeting and ask for the details of the "considered "wetland proposal. You will get the same answer l did. Outfall. Outfall. Outfall. A bit like Barnaby and Labor. Labor Labor.... blah blah blah.

    Marianne Kambouridis Marianne Kambouridis 7:54 pm 28 Apr 19

    CONSTRUCTED WETLANDS FOR STP UPGRADES

    A WATER UTILITIES EXPERIENCE AND INITIAL PERFORMANCE RESULTS

    Andy Constantinou1 Vanessa Personnaz 2, Ian Kikkert 3 Ted Aston4

    1. Queensland Urban Utilities, Brisbane, [email protected], 0488 734 830

    2. The Water and Carbon Group, Brisbane, [email protected], 0438 412 899

    3. The Water and Carbon Group, Brisbane, [email protected], 0437 000 628

    4. Queensland Urban Utilities, Brisbane. [email protected], 0421 336 221

    ABSTRACT

    This paper presents Queensland Urban Utilities

    decision making process on selecting a constructed

    wetland as the process solution of choice to

    upgrade a regional sewage treatment plant at

    Helidon,

    By February 2013 the construction of an

    engineered free water surface wetland was

    completed with the purpose of providing further

    treatment for the lagoon effluent. In addition to the

    construction of the wetland, two stub baffles were

    added to the first lagoon to reduce the risk of short

    circuiting as a result of the new inlet/outlet

    arrangement.

    Lagoon STPs can be a cost effective technology for

    the treatment of wastewater, particularly in rural

    areas which have a low population density and land

    availability is not limiting.

    In addition to requiring a higher footprint compared

    to more traditional sewage treatment technologies,

    the performance of lagoon STPs is often

    compromised by high effluent TSS and

    consequently, elevated effluent BOD. This is due to

    the presence of algae released in the effluent,

    which unlike bacteria in activated sludge processes,

    do not form readily settlable flocs. The algae is

    however critical to the functioning of facultative

    lagoons, as they provide biological treatment as

    well as producing oxygen in the presence of light to

    facilitate the growth and functioning of bacteria that

    provide further treatment. The Helidon STP noncompliance

    was attributed to the presence of algae

    in the effluent. (See historic results in Figures 4-7).

    WHY WETLANDS

    A project to address the deficiencies with the lagoon process at Helidon STP was initiated by QUU’s Planning Section following an investigation which identified that standards of service were not being met. A Terms of Reference was prepared for a feasibility study to be carried out by an Engineering consultant. In seeking to find a cost effective solution, low technology, passive treatment solutions which closely resembled the existing process were favoured. The solution prioritisation was set as follows in order of preference:

    1. Maximise existing assets;

    2. Retrofit and modify existing assets;

    3. Application of additional low technology; and

    4. Application of more complex technologies.

    PROCUREMENT

    The scope of the proposed contract was for:

    • The construction of a Free Water Surface Wetland including earthworks, planting and plant establishment;

    • Works as required for the integration of the wetland into the existing lagoon process;

    • Minor works to the existing lagoons to accommodate the wetlands and improve operational efficiency;

    • Operational and maintenance support for a period of twenty four months after practical completion; and

    • Provision of performance guarantees.

    PERFORMANCE RESULTS

    . After the six months establishment phase, BOD and TSS have decreased to below the license limit and pH values have stabilised to within a 1 unit range. Finally, Total Nitrogen (TN), although not a licenced limit, has shown significant reductions compared to previous seasons.

    Overall, the actual treatment performance of the wetland has been demonstrated to exceed the modelled results for BOD and TSS 50th %ile and 80th %ile values. This confirms that the wetland models used to design Helidon were a reliable tool to predict performance in the field.

    LESSONS LEARNT

    While constructed wetlands are a less complex passive treatment solution it was evident that it is critically important to engage the specific expertise during the design, construction and establishment and to communicate this knowledge with operational staff during the project and handover.

    Another lesson learnt was the need to manage algae during wetland establishment – internal and external algae. The project provided an opportunity to further refine the effectiveness of some of the common strategies employed, to make them more effective. Further enhancement of the inlet gravel beds were made to support the other temporary control strategies instigated during the establishment period.

    The criticality of achieving accurate finished surface levels within the wetland cannot be overstated. In the Helidon STP wetlands, finished surface levels were slightly affected byflooding experienced during the high rainfall event in February 2013, a day after the wetland planting. This unforeseen event required the water level to be managed promptly for plant survival. Minor grade loss across the width of the cells was also observed with the heavy inundation causing the plant media to settle within the cells. The subsequent slight difference in water level across the cell meant that the cell depth and drying phases needed to be managed with greater sensitivity. Despite showing some visible differences in plant growth early on, after 12 months the impact has proved to be a temporary one which no longer has any noticeable effects.

    Another challenge encountered at Helidon was the presence of turtles in the facultative pond. During the HAZOP workshop, turtles were discussed but were not considered an issue for the Helidon STP. Unfortunately, turtles were in far greater numbers than initial thought. Turtles found their way to the transfer pipe and wetland inlet distributors. To address this, a pit with 20mm stainless steel screen was installed downstream of the pond outlet preventing future blockages.

    CONCLUSIONS

    QUU have achieved a dramatic improvement to the effluent quality discharged from the Helidon STP by installing an engineered wetland at significantly lower cost than the alternative and have significantly lessened the operational requirements environmental footprint in comparison to a more mechanical solution. The wetland model used to develop the Helidon STP also proved to be an effective tool for designing a suitable wetland system with the actual performance showing good agreement in terms of TN results whilst actually outperforming in terms of BOD and TSS.

John Browne John Browne 9:45 am 26 Apr 19

The biggest polluter of beaches is from storm water runoff in urban and town areas NOT sewage. The outfall is the best environmental option for STP overflow. It's basically putting treated/filtered fresh water into salt.

    Stephen Kambouridis Stephen Kambouridis 1:44 pm 26 Apr 19

    But why waste clean water? The ocean doesn't need any more. The inland does.

    Marianne Kambouridis Marianne Kambouridis 2:32 pm 26 Apr 19

    Not the best option John Browne. Do a search on the Maleny Project and you will see what is possible with the current technologies.

    Marianne Kambouridis Marianne Kambouridis 4:50 pm 26 Apr 19

    Stormwater is definitely not good for our oceans and this too needs to be addressed. The stormwater can be piped into Panboola wetlands but our council can only cope with one issue at a time ;-)

    Allan McIntyre Allan McIntyre 7:24 pm 27 Apr 19

    Marianne Kambouridis wouldn't you think at times when there is excess stormwater, that Panboola wetlands would be at near maximum capacity already from local runoff and adding excess stormwater from elsewhere could be detrimental to the system. If your able to store the water and use in dryer times yes its possible.

    Fraser Buchanan Fraser Buchanan 8:38 pm 27 Apr 19

    The Golf club have floated the idea of putting a massive holding capacity at the top of their course in the bush and developing and converting their other dams into effluent ponds, soaks, reed beds, etc linked together meandering down through the course as an extra polishing process with the effluent finishing back at the treatment works ready for distribution to reuse users and or disposal through exfiltration trench....what a great concept another concept that has never been given any consideration by the council or the previous focus group.. amazing how things can change and evolve over time..

    Marianne Kambouridis Marianne Kambouridis 2:27 pm 30 Apr 19

    Allan McIntyre, Panboola cannot take any of this treated effluent due to the oysters, however, as mentioned earlier, dams on the Golf course and on farms are avaiable for storage, use, irrigation and the cycle continues throughout a wet year also with minimal discharge that can be treated to a very high level which means we could keep the outfall on the beach, negating the need and expense of a deep ocean outfall of $30 million.

Annie Clarke Annie Clarke 9:13 am 26 Apr 19

Great article Ian, I can't imagine that one person would consider and ocean out fall a good idea in this country.

So, what do inland towns do, with poo?

Surely there are many close and inventive examples with inland towns, too be honest I've never given it alot of thought.

What happens to POO in the ACT?

    Marianne Kambouridis Marianne Kambouridis 4:48 pm 26 Apr 19

    Exactly Annie Clarke. Because we have an ocean nearby, we apparently can abuse it! Australia has over 250 ocean outfalls and the Clean Ocean Foundation is working with communities, and ours, to educate councils into alternative systems.

    Ruth Maher Ruth Maher 5:52 pm 26 Apr 19

    Annie Clarke goes into rivers, tributaries, creeks

    Bill Jackson Bill Jackson 7:22 pm 26 Apr 19

    Canberra's treated effluent is emptied into the Molonglo river just upstream from its junction with the Murrumbidgee. 80 to 90 million litres a day.

Stephen Kambouridis Stephen Kambouridis 8:28 am 26 Apr 19

Inland irrigation. Created wetlands. So many solutions, so much information available. I don't believe there are many who want the development that an outfall system would allow. A large wetland system would encourage Bird life and tourists. Sounds a NO brainer.

Kasdon Haantjens Kasdon Haantjens 8:10 am 26 Apr 19

Pump all coastal treated sewage inland and grow Hemp or Ironbark

    Marianne Kambouridis Marianne Kambouridis 4:49 pm 26 Apr 19

    Yes, if anyone out there has land closeby and is willing to lease it to our council, then this would be a great help! I know of two farmers who are very serious about getting this treated effluent.

Ann Wright Ann Wright 8:01 am 26 Apr 19

No ocean outfall please, irrigate and save a fortune at the same time.

Julie Pennefather Julie Pennefather 7:55 am 26 Apr 19

Surely we are smarter than this😥

Samala Morgan Samala Morgan 7:44 am 26 Apr 19

Irrigate!

Bev Tennyson Bev Tennyson 7:36 am 26 Apr 19

Why can't this water for irrigation? This is such a waste Non food pasture would benefit from this water Just saying

    Marianne Kambouridis Marianne Kambouridis 2:30 pm 26 Apr 19

    Certainly would be better to reuse as much of this as we can Bev. Go to Merimbula/Pambula Wastewater Alternatives where you will find heaps of examples of alternative ways of managing wastewater.

Simon Haynes Simon Haynes 7:36 am 26 Apr 19

Good luck.

NSW government interest in the environment seems to have disappeared after the recent election.

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