Landfills are extending their lifespans and saving thousands on operating costs by using Posi-Shell as a daily cover system.
A daily landfill cover system has been saving landfill managers time and money in more than 300 sites around the world.
Originally developed in the US, Posi-Shell is now manufactured in Australia by landfill equipment supplier Envirofix.
Posi-Shell is a patented blend of mineral binders, reinforcing fibres and polymers that, when mixed with water or leachate, turns into a thin but durable stucco-like material. It’s applied by a specific applicator that sprays the material onto the landfill at the end of each day where it forms a daily cover.
Richard Woolley, Director at Envirofix, says the Posi-Shell requires substantially less capital for landfill operators than the machinery required to spread soil onto the tip face.
“Posi-Shell is cheaper and quicker to apply. It also requires a fraction of the fuel, and no specially trained or skilled labour to apply it. Because it’s a spray-on system, it’s also totally scalable to any size or shape of landfill,” Richard says.
“As the amount of waste being sent to a landfill on a day-to-day basis can fluctuate, Posi-Shell can be applied to suit each day’s needs, with any remainder able to be carried over and used for the next day.”
By replacing traditional soil cover, the Posi-Shell system dramatically preserves landfill airspace. Richard says this is a major benefit for landfill operators looking to extend the life of existing cells.
“Landfills are very expensive to build, so it’s important to make them last as long as possible and get the best return from the available airspace,” he says.
“It is applied quite thinly, at around three to five millimetres thick. When the next load of waste is applied, it breaks up and avoids creating layers of soil so as to not limit landfill gas production.”
Another unique property of Posi-Shell is that it is non-flammable wet and dry and can also be used to put out and prevent landfill fires.
“On top of that, the applicator also doubles as firefighting equipment and can be used to put out fires if any occur, with no need to double up on equipment,” he says.
It has also been developed to manage strong odours, with a neutraliser used in the solution.
“Because Posi-Shell creates a sealed layer, odours aren’t able to escape and spread,” Richard says.
“This can be critical for landfills that handle particularly odorous waste streams.”
Richard says he hasn’t found a landfill that couldn’t benefit from the system, with all sizes being able to take advantage it.
“In particular, Posi-Shell provides a fantastic solution for smaller regional landfills that are looking to reduce the running costs and high capital cost of expensive machinery,” he says.
“Both large and small sites share similar challenges, often finding it difficult to source cover material, not to mention the cost involved in moving and spreading it.
“Being a totally scalable and a non-geometric system, Posi-Shell is easily implemented into a landfill’s daily operations. This technology is an exciting opportunity for the industry and offers many advantages for operators to reduce operating costs and extend the landfill life.”