A good sense of waste

Michael Dobbs, Environmental Health Officer – Ballina Shire Council NSW

From 1 July 2009 the NSW Labour Government introduced the waste and environment levy to include local government areas in NSW along the coast north of Port Stephens to the Queensland border and west of Sydney to the Blue Mountains and south of Wollondilly.

This extended area became known as the “Regional Regulated Area” and the authority to attach the levy to these facilities was derived from application of “section 88 of the POEO Act 1997 (POEO Act)”. This meant that occupiers of certain scheduled waste facilities are required to pay the waste environment levy, similar to the charged to waste facilities in the metropolitan areas of Sydney, Wollongong and Newcastle.

The introduction of the waste and environment levy was meant to provide an incentive to waste facilities to recycle, reuse and reprocess materials for reuse in the marketplace. A deduction from payment of the S88 levy can only be claimed when waste is either:

• Transported from a waste facility to another place for the lawful reuse, or
• To another facility for lawful recycling, processing, recovery or disposal, or
• Where waste is used for an approved purpose

The current rate for Regional Regulated Areas is $10.00 per tonne with a rise of $10.00 + CPI in July for each of the next 6 years.

The levy is meant to be an economic driver of the resource recovery and the recycling and processing of waste in order to divert and minimise waste to landfill. The State Governments objective as enunciated in legislation  is for the diversion off 66% of waste currently disposed of to landfill by 2012

The levy is applied to all waste entering the landfill excluding waste approved for operational purposes. As each year passes the cost to councils of disposing of waste to landfill will increase along with the fees Council will be required to charge in order to recover costs. It is thought that this will drive programs that will reduce waste to landfill or provide an incentive to develop alternate processing and disposal methods.

In addition to the costs of disposal, the cost of licence compliance has also increased substantially. Materials entering the landfill for the intermediate capping, cell maintenance and road works, are now subject to the levy. This has immediate financial implications for the daily operations of the landfill due to licence conditions or licence compliance issues such as daily cover.

Prior to July 2009 sites were able to source shale/clay for $7 – 15 per tonne, but by placing the current $10.00 levy on top of this the cost of materials required for maintenance works and licence compliance has nearly doubled, as only approved final capping and cell construction materials attract the “approved operational purpose” levy exemption.

Within 5 years with the levy at $50.00 (+CPI) per tonne, landfills will only remain sustainable by establishing cost efficient recycling and reprocessing techniques and reuse recovery of materials for onsite purposes with daily cover, cell and road maintenance attracting the levy.

The DECCW initially indicated that 50% of the levy would be returned to Council for approved purposes which would generally involve sustainability and waste reduction, with the approved purpose not being specified or tied by the regulators. However, as the levy approached this was reduced to 50% of the levy pertaining to municipal kerbside collections, and the money could be used for purposes determined by the regulators. If a Council did not have approved programs as per the regulators’ deemed purposes, they risk not receiving the levy return. Additional, the amount was reduced to a percentage of the pool of funds dedicated for the payment by the State Government to be determined on a pro rata basis.

Jane McCrory, Mandalay Technologies

A little outside of the normal scope of A Good Sense of Waste articles, but I thought that you would appreciate the skill involved in working with such an unweildy material that’s normally seen as a pain to deal with! One man’s trash is another man’s…art?

Sam Bateman, Hanson Landfill Services

Hyder have completed a landmark LCA on the Wollert Landfill in northern Melbourne compared with AWT that concludes “While there is no clear “winner” amongst the scenarios and technologies assessed, all of them – including the current base case involving disposal at Wollert landfill – resulted in net savings of greenhouse gases.”

A far cry from the “we must divert organics from landfill at all costs” brigade!  Looking at the detail of the study the key variables were the efficiency of the methane capture at Wollert, the storage of carbon at Wollert and the net export of electricity from an anaerobic digestor.

Wollert has been conducting a series of emissions measurements over the last 2 years using flux box technology developed by Dr Stuart Dever at GHD.  The results were remarkable in that they found emissions of methane were much less than anticipated, especially from the current cell with no collection infrastructure.  The measurements showed that fresh waste takes considerably longer to start emitting methane than has been assumed and even then the emissions are low.  This is thought to be due to composting of waste in the early days and methane oxidation in the later stages.  The result is that methane collection efficiency on a whole of site basis is between 68 and 88 % using conservative upper and lower bounds.

Carbon storage in landfill is now an established scientific fact.  Long term accelerated degradation studies have found significant proportions of the organic fractions of the waste do not decompose in simulated landfills.  This is related to lignin in the waste that is known not to degrade in anaerobic environments.  The non-degraded organics effectively store carbon from the atmosphere permanently.  This is encapsulated in the IPCC models as the DOCf factor.

Anaerobic waste technology providers claim they have an net export of electricity, but this is yet to be demonstrated in Australia.  The LCA used a range of zero to 68 kWh/t based on manufacturers data.  Wollert landfill have demonstrated very reliable net export of over 100kWh/t and can achieve 160 kWh/t over the long term.

This study has ramifications for policy makers and alternative technology providers in that it is no longer tenable to claim that just diverting organics from landfill will save tonnes of CO2eq in greenhouse emissions.  Even in the worse conceivable case Wollert reduced greenhouse emissions rather than increased them.  With the perspective of energy recovery in mind, landfill far out performs any alternative except incineration and all with almost no greenhouse emissions.

Rob McGahey, Senior Waste Industry Specialist

Caterpillar Asia-Pacific

With the majority of the landfills getting close to capacity in Melbourne and Sydney, some landfill operators are still struggling to understand what influences the compaction of waste and how that can impact on their future business and earnings. Where will new landfills be? If they are out of the regional areas will there be additional costs involved in the collection and transportation of wastes to their final destination? By reviewing your compaction rates, opportunities exist to extend the life of your existing landfill while assessing alternative options.

Compaction is not relative to the operating weight of the machine alone – there are a number of factors that can affect it. These include ground pressure of the compactor, waste type, layer thickness (not daily lift thickness), amount of passes, working up hill or down hill and the ability to track where your compactor has been working on the face to ensure you are getting a good coverage of each layer.

Ground pressure is the one most landfill operators have difficulty in understanding. The easiest way to explain it would be to look at two dozers with the same operating weight and one with a Low Ground Pressure (LGP) track and the other with a standard track. You could drive your LGP dozer over a piece of soft ground and leave little or no imprint as it has spread its weight over a larger area, but drive the standard track dozer (same operating weight) over the same ground and you will see it sink into the tracks left by the LGP. This is the same with compaction – more ground pressure means more compaction (for the same layer thickness).

If you are able to increase your compaction rate by just 5% from what you are doing today, what would that offer you? For example, on a landfill that had a projected life of 10 years, if you were able to increase your compaction density by 5% you would be able to receive another 6 months of waste. What is this worth as revenue through the gate alone?

Fuel consumption is another factor that is important when looking at landfill compactors. You need a performance or production-based fuel consumption rate – hours per litre are of no use as you don’t know if the machine was idling or working or how hard it was working for the numbers you see. Fuel consumption should be measured by either litres used per tonne of waste handled (l/t) or litres used per tonne per cubic meter compacted (l/tm3), the same as you would do with a mining truck l/t (weight), or a dozer l/m3 of rock moved (volume).

So understand what your needs are then ask the questions to make an informed decision about your situation.

Olivia Robertson, Mandalay Technologies

Many councils in Australia are faced with the challenge of deciding what type of gas management system to install as EPA/DERM licensing requirements for maximum waste tonnages to landfill are reached.

What can councils do when placed in this position?

• Perform more investigations to ensure gas generation estimates are correct
• Install more gas wells and monitor them
• Confirm requirements with EPA/DERM
• Install a flaring system
• Continue to investigate gas extraction systems and power generation
• Perform CPRS calculations with a cost-benefit analysis completed for an active and non-active gas extraction system

Councils are placed in a position where they have to engage consultancy companies to carry out future landfill gas generation assessments to ascertain present and future landfill gas generation. These companies use a range of overseas kinetic models which provides an estimate of the possible production that can be expected under certain conditions (and can only be used a predictive model).

What options do councils have if they have to install a gas extraction system?  There are four:

• Design and Construct – contractor to design, construct and commission, council engages a specialist contractor to operate
• Design Build Operate (DBO) – Council engages a contractor to design, build and operate. Contractor to be paid based on $/MWh of electrical output. Council to receive all monies from sales, renewable energy credits and carbon credits.
• Joint Venture/Partnership – share all costs and revenue
• Build Own Operate (BOO) or Build Own Operate Transfer (BOOT) – council engages a contractor to design, construct and commission and operate and Council to receive a royalty.

Queensland faces a more limited range of options, given the lack of waste levy and associated lack of revenue from this source. DBO is the most feasible of the above options for Qld.

It appears Victorian Councils are leading the way in the uptake of this technology, engaging LMS and EDL to design, construct and operate the gas extraction systems on council-owned landfill sites. The council may then be paid a royalty on % of revenue earned by the contractor (gas extraction company) generally in excess of a base amount. Councils such as Wyndham, Geelong, Whittlesea, Hume and City of Melbourne have all been involved with such projects which have been extremely conducive to revenue raising.

Mike Ritchie, Mike Ritchie & Associates

In response to Sam Bateman’s article ‘Energy Recovery from Waste’, no-one including me has an issue with landfills capturing gas and using it to generate electricity. It is a brilliant use of a waste product. The more we do of it the better. The higher the national gas capture rate the better. The more energy we can extract from landfills the better.

Sam wants more organics to go to landfill, generating more gas which can be turned to electricity. Sounds sensible?

Where the argument falls down is that landfills cannot capture all of the gas. Fugitive emissions leak out from the landfill as methane. Methane is a potent greenhouse gas with a climate forcing effect of 21 times carbon dioxide.

So the more organics we put into landfill, the more fugitive emissions there are and the more we contribute to climate change.

If landfill gas capture rates could be substantially improved I would be agreeing with Sam (for organic waste anyway).

But there are real structural, engineering and cost implications of trying to capture all of the methane from a landfill.

The IPCC estimates that gas capture could be as low as 20%.

Work by Hyder Consulting showed that the balancing point was 90% gas capture. That is the capture rate you would need to achieve where the carbon savings from generating electricity from methane equalled the climate change effects of the fugitive emissions. Only a couple of landfills in Australia could claim above 90% gas capture rates.

The idea of putting NEW organics into landfill just does not stack up. Even if you take a conservative middle position of a national 60% average gas capture, the environmental costs of the fugitive methane emissions greatly outway the environmental benefits of the green electricity created.

The best thing to do with the organics is compost them, or anaerobically digest them in an fully enclosed system which captures 100% of the gas.

Which brings us back to the key point. We need to massively increase methane capture rates at landfills in Australia. One point often missed in the debate is that capturing gas is an expensive exercise. Capturing all of the gas is cost prohibitive.

Landfill gas capture can be managed for an ECONOMIC return or MAXIMUM gas capture, but you can’t do both at the same time.

What do I mean by this?

Continue Reading…

Sam Bateman, Hanson Landfill Services

The new leader of the Liberal Party has come out with the mantra that the Rudd Government’s ETS is just a “massive new tax”.  This is a classic political fear campaign.  Everyone that thinks about the threats posed by climate change agrees that to have any chance of solving the problem there must be a cost put on CO2 emissions – in other words, a cost on carbon.  The cost of carbon is an external cost that the user of that carbon currently does not experience, but the rest of us experience it collectively.  To redress this failure a cost must be imposed on carbon, otherwise society will continue with business as usual until climate change creates so much dislocation that the cost of the results of climate change forces us to change.  The ETS is a way of putting a cost on carbon now before that happens, with the least chance of political interference down the track.  All the government has to do is set a trajectory for emission permits (which in effect will be set by international agreement) and then issue permits for auction each year that meet that trajectory.  The money raised can be spent in a number of ways: compensating affected people, building mitigation schemes, providing assistance to other countries, etc.

However, like all government tax funds, it will be spent eventually in the community and can provide impetus for change.  A cost on carbon will impact us all and lead to a change in our behaviour.  When petrol prices go up, people buy cars that use less fuel or drive less; and so emissions from transport goes down.  We all know that.

The City of Stirling recently posted a blog about implementing a one bin policy and the success it’s had with recycling rates. One of our readers asked whether the City of Stirling used a side loader truck.

Attached is a diagram that explains the process City of Stirling uses to sort recycling from waste using a one bin system.

City of Stirling one bin policy – download.

Keith Rickman – Coordinator Waste Services, City of Stirling (WA)

All local governments in Western Australia are charged by the Western Australian Government with a responsibility to manage our waste streams so as to reduce the waste going to landfill to towards zero by 2020.

This means that every item in the waste stream must be seen as potentially recyclable. Multi-bin systems are generally structured around a view that householders can sort bottles, cans and paper out of the waste stream into a separate yellow-lidded wheelie bin. The rest is treated as rubbish. This approach only recovers in the order of about 14% of the household waste stream after you recognise that not everyone recycles and some people make mistakes and large quantities of the contents of these yellow-lidded bins are discarded as rubbish.

The fact emerging is that the more bins we provide and ask householders to sort in to, the more mistakes they make and the more difficult it is to recycle the material. We must also recognise that every additional bin collection introduces more fuel guzzling trucks in to service them, belching smoke and noise into the residential neighbourhood. Our community demographics are changing to the point that the Australian Bureau of Statistics reports that by 2020 up to 30% of all households will be single person households – and single person households are the worst recyclers of any demographic group in the community.

To meet all of these objectives the City of Stirling has adopted ground-breaking technology: using only a single bin, and by mechanical and manual means separating the contents of household waste. This allows the City to recycle glass and plastic bottles, steel and aluminium cans as well as all of the food and garden waste in the bin. The waste diverted from landfill by our single bin process stands at 69% and since the program’s inception has diverted over 220,000 tonnes from landfill. Single bin technology ensures that everyone recycles in the City of Stirling – no choice.

The City engaged an independent report by the Carbon Reduction Institute of NSW comparing the single bin technology to the traditional two bin system. The report determined that the City’s single bin system delivers the best environmental outcome as it produces 50,000 tonnes less greenhouse gases.

Sam Bateman, Hanson Landfill Services

When it comes to recovering energy from waste, landfills are far ahead of the alternative waste technologies (except for mass burn incineration). While anaerobic digestion of mixed waste claims to generate up to 150kWh/tonne of waste, 125kWh/tonne is needed to process the waste through the plant (thereby negating most of the benefits of the process). The reliability of the waste digestors is also questionable and electricity purchasers do not offer a premium base load price for the output.  The UR-3R plant at Eastern Creek NSW has created only 7500 MWh of renewable energy certificates (RECs) since it opened in 2005, though to be fair it digests only part of its organics.

In contrast, landfill can recover over 100kWh of electricity per tonne of waste with minimal internal energy use. Landfills have created 2.6 million MWh of RECs from 52 projects around Australia since 2005. This is an average of 50,000 MWh of RECs per site.  Landfill gas power is considered so reliable it attracts the base load power premium from the electricity purchasers.

The recovery of energy from landfill sites can provide a good income to the landfill owner.  Usually the contractor will construct the wells, pipes and electricity power station at no cost to the landfill owner and pay a royalty on the gas consumed.