US engineer Neal Bolton explains the nuts and bolts behind landfill management and the difficulties operators continue to experience in managing their airspace into the future.
Esteemed US author and waste consultant Neal Bolton has focused his 40-year career on changing the status quo in landfill management.
In 1988, at the age of 29, Neal became an engineer, having previously worked as an equipment operator managing landfill operations and projects. From there, he decided to set his sights on engineering-consulting work, and established his own company, Blue Ridge Services in California. Neal’s experiences led him to believe that many landfilling practices were impractical or outdated, and he decided it was time to make a change.
“I was seeing a lot of things that weren’t efficient and I would ask people: why do you do this that particular way? Pretty often they wouldn’t have any other answer besides ‘that’s the way we’ve always done it’,” Neal explains.
As a waste consultant in the early 90s, Neal began to perform a cost-benefit analysis on daily landfilling practices across the US and soon discovered many businesses weren’t operating as effectively as they could be.
In 1995, Neal wrote what he says was the only book in the world at the time on landfill operations, titled The Handbook of Landfill Operations. The book aimed to break down landfill operations and discuss how they align with engineering concepts. It was targeted at landfill engineers, owners and operators.
“That became a turning point for me. We discovered we knew things that most people didn’t know and we wanted to spread the message to industry,” Neal says.
Neal’s goal was to make landfill operators consider whether their operation was truly the most efficient or cost-effective. It remains the central focus of Blue Ridge Services today.
“I’m a really practical person. I like to put numbers to things that are abstract and a lot of my work has been based on boosting airspace and compaction rates,” he says.
“We conduct financial and productivity analysis on practices people might never have even thought about.”
As a result of his audits, Neal discovered that landfill economics largely boiled down to costs versus revenue. Costs involve labour, equipment and capital expenditure for facility development, while revenue revolves around one principle – a landfill’s airspace.
A SIMPLE ASSESSMENT
In 2015, Neal developed the company’s trademark CORE Assessment, which stands for Comprehensive Operations Review.
“Every landfill has its own strengths and weaknesses and within that landfill is a unique quantity and value of airspace,” Neal explains.
“We work on an array of projects, but the one we do most commonly is the CORE Assessment. I have personally worked at more than 500 landfills in the last 40 years.”
It all begins with more efficient compaction, which can generate increased airspace, extending the life of the landfill and providing more revenue for the operator.
In a 2017 webinar, Blue Ridge Services polled 40 landfill managers, asking them how important compaction was, with 80 per cent highlighting it as their most important operational issue.
Neal says waste compaction is one of the most critical steps to optimising landfill airspace. It’s a simple concept: waste that is compacted better takes up less space, which means more available airspace to fill with more waste.
In Australia, optimising landfill airspace is of particular importance as the industry becomes constrained by environmental requirements, according to the 2009 report by Hyder Consulting – Australian landfill capacities into the future. The report highlights the number of landfills have been declining as waste streams are consolidated in larger, regional sites.
While the report found no evidence of a critical shortage of landfill capacity at population centres, it argues as landfills close, they are replaced by sites that are further away, so that the cost and environmental impact of transport is greater. Long-term problems with landfill capacity are deemed likely in two of the nation’s urban centres – south-east Melbourne and metropolitan Sydney.
Despite a push towards more recycling, Australia’s dependence on landfills remains firmly intact. The National Waste Report 2013, for instance, found landfills receive 40 per cent of Australia’s waste. Airspace therefore is a valuable commodity for operators and it’s why consultants such as Neal continue to emphasise its importance.
“Once you understand the value of airspace, then you can crunch the numbers to determine whether you need a larger bulldozer, compactor or alternative daily cover – or a combination of all of these.”
But he says achieving great compaction isn’t just about running a compactor longer, it’s about maximising the compactor’s effort and minimising waste. This is commonly achieved through equipment utilisation studies, where an operator is observed over a period of time. From this observation, areas of inefficiency can be identified and corrected.
“When we conduct these types of studies, we often recommend reducing machine work hours or even the number of machines which aims to improve the overall efficiency of the remaining machines. It’s all about working smarter, not harder,” Neal says.
THE BUSINESS OF AIRSPACE
As operators cover their landfill each day with alternative daily cover or soil, the value of airspace can vary. Neal says some landfills will have a higher cost of airspace in highly populated areas, while regional locations will process less waste and therefore the market value is considered lower. Others will have varying soil requirements which can boost the value of airspace.
Many landfills use soil as daily and intermediate cover, but there is a range of options for alternative daily cover (ADC). Non-waste-derived ADC usually comes in the form of spray-on foam, geo-synthetic materials and tarpaulins.
Neal says most landfills can benefit by switching from soil to ADC, as it is often more cost-effective and consumes less airspace. He says it can take up to three hours to excavate, move, tip and spread soil. That’s not to mention the difficulties satisfying environmental regulator authorities to cover landfills with a specific layer of soil and the challenges in actually measuring this. He says one of the best ADC options is tarpaulins. This type of ADC is rolled out over the waste at the end of the day, and then removed at the start of the day.
“We have often recommended Tarpomatic to our clients, which is one of the most efficient and cost-effective tarping systems available on the market,” he says.
According to Steve Brooks, Managing Director of Tarpomatic Australia, a landfill using a Tarpomatic with a working face of around 500 square metres might be preserving up to 500 cubic metres of airspace each week when compared to soil-based cover. That’s in addition to the savings made in time, machine hours, fuel and labour. Steve has calculated that for a site with a gate fee of $150 per tonne and a working face of 500 square metres, the value of the airspace that is filled with soil cover in just one week is around $75,000. In Victoria, where the daily cover requirement is 300 millimetres of soil, this is $150,000 per week.
A self-contained unit, the Tarpomatic ATM can be attached to the front of a landfill compactor or dozer, giving the operator the ability to seamlessly deploy or retrieve the specially designed heavy-duty tarpaulins over their working face. Each Tarpomatic ATM can be adjusted to suit the specific bulldozer or compactor, ensuring quick and easy attachment and removal.
Neal says the unique selling point of the Tarpomatic is its interchangeable spool, which allows for an unlimited amount of coverage with the one machine.
Among the host of benefits is also an odour control unit, which alleviates odours, litter, dust and leachate. Steve adds that alternative tarpaulin systems don’t last anywhere near as long, so operators could end up spending more over time.
Another quality of the technology is its durability. Tarpomatic’s tarpaulins are constructed using a heavy-duty dual-layer laminated polyethylene fabric and each tarp has more than 150 metres of heavyweight chain built in so they weigh 400 kilograms each. It means the tarpaulins remain in place in the event of strong winds.
COMMUNICATING THE VALUE OF AIRSPACE
Neal believes one of the challenges in educating operators on the value of airspace has been a miscommunication between landfill operators and engineers.
He says he has worked in 45 states in the US, along with some Canadian provinces, parts of Australia and other nations. In Neal’s experience, changing archaic practices requires a strong communicator who can articulate the financial benefits in a simple way.
“You’ve got people who have been in the business a long time and operate landfills traditionally and then you have people who are scientific and engineering-minded that perform geotechnical and engineering work,” Neal says.
“But those two groups don’t communicate well together, because engineers speak in an engineering language and operators don’t and that’s where our company comes in as the translator.”
He says Tarpomatic’s Steve Brooks has done an exceptional job communicating the value of ADC to the industry.
“Steve has taken a personal approach to laying out the benefits of his product. He’s in the same boat as us in taking an untapped technology and demonstrating its value to the industry.
“Fortunately for Steve’s customers, the benefit from Tarpomatic is phenomenal – it’s a very fast pay back.”
But all in all, Neal says the key benefit of the Tarpomatic is its cost savings.
“If you took a large landfill and looked at the capacity, and multiplied that against the gate fee, it’s not unusual to have large landfills show that they’ll generate more than a billion dollars over their lifetime,” Neal says.
“Aside from these considerations, there are safety issues, we need to make sure we’re working safely. There are environmental issues in protecting the groundwater and surface water and odours, but in the end if you don’t manage your airspace properly, you just won’t have the money to do those other things right.”
Faced with increasing pressures to reduce costs, Neal says he believes countries such as Canada and Australia are now playing catch-up to the US. He says they are up to a decade or so behind in applying efficiencies and techniques to their landfill, despite their effective use of liners, groundwater monitoring and, in some cases, ADCs.
“In Australia, you’re going to see over the next few years a tremendous increase in the awareness of the technology we have and learning how to compact better and use ADC better.”
As previously reported by Waste Management Review, in 2016, dozens of old Victorian landfills were suspected of leaking potentially toxic materials into soil and waterways.
While many landfill operators are operating to best practice, there have been some incidents of unlined landfills. Last year, the Environment Protection Authority Victoria (EPA) noted engineered landfill liners of a certain standard were not compulsory until 2004, when a new EPA policy came into effect.
Although, the EPA notes, the standards were previously well documented.
“When you talk about leachate or landfill gas that might not show up until closure, almost all of those can be traced back to practices during the operational phase of the landfill,” Neal says.
“If you have excessive leachate it’s probably because you weren’t maintaining good surface drainage as you constructed the landfill and filled it. This is the awareness I think Australian landfill operators are going to come to over the next few years.”