Rapt to be included in the December 2022 Contractor magazine, talking about our custom waste recycling plant, which takes hydroexcavation waste and separates it into clay, fines, sand and water. It was important to us as a company to develop a more sustainable way of dealing with waste and so far we estimate we’ve diverted over 2000 cubic metres from landfill.
See the December issue of Contractor magazine or read the article below:
HydroVac’s sustainable solution for waste
Andrew Williams used to look at the mountains of waste his waste management company HydroVac had to dispose of each month and think, “There must be a better way”. The HydroVac fleet of 57 hydroexcavation, septic and sucker trucks can deal with anywhere from 60-120m3 of waste a day from their work with construction and residential clients. This waste would traditionally end up in settling ponds, where the waste is left to dry and the water run-off primarily ends up in our waterways.
“I knew we needed to do better,” Williams says. “We’re always aiming to be environmentally responsible and offer our clients better solutions, so it was important to us to find a better way to deal with our waste. We were really keen to close the loop, rather than just taking waste from one place to another.”
With no off-the-shelf waste recycling plants available that ticked all the boxes for HydroVac, Andrew spent three years researching relevant technology and looking at other industries – such as mining – for inspiration.
“I went all over Europe, looking at different ideas. I checked out all kinds of industries to see how they were processing for their individual needs. Then I worked with our in-house engineer Brett Bowyer who is very clever and together we adapted learnings from those other industries to make our own custom design to suit our needs,” he explains.
The resulting HydroVac Waste Recycling Plant, set up in their Hobsonville yard in Auckland, sees drivers pull up at a dumping bay and unload. The waste is then put through a process that separates it into rock, metal, sand, mud and water. The water then goes through a further process of flocculation.
These valuable by-products are all recycled and reused in other ways, including drainage works, roading, horse arenas, farm tracks and landscaping.
“We’re currently talking to construction companies about taking the washed aggregate and using it on site. This means we can create that sustainable circuit by reusing waste products and they can feel good about being a part of that loop by using recycled materials. At this stage for us, it’s not about the money but about doing the right thing,” Williams emphasises.
100 per cent of the recycled water produced is reused. HydroVac trucks now use only recycled water, taking nothing from the grid – not only is this an environmentally friendly approach, it also gets around the very real issue of water being a scarce resource in Auckland, especially in peak summer.
“The trucks pull up, dump their load, wash out the truck with recycled water, fill the truck up with recycled water for their next job and then head off,” Williams says. “We also offer the water to key clients to use for dust suppression on jobs.”
The unique recycling plant went live in October 2021 and today it handles anything from 60 to 120m3 a day. Of that, 40% ends up as clay, 30% as water, and 30% aggregates (rocks, stones, and sand). So far, Williams estimates the plant has diverted well over 2000m3 from landfill.
The plant can be run by one person (HydroVac has two, to allow for sickness and days off), who is tasked with driving the loader to move the recycled materials around, flocculation of the water, and signing people in and out of site.
A more recent addition was the scales, so drivers can weigh their load before and after disposal, giving clients a true cost instead of a guesstimation. HydroVac also allows selected contractors in to make use of the facility for sustainable disposal.
“The feedback we are getting from clients has been amazing. We don’t know of anyone else treating their waste like we are, and clients are really happy that the waste from their sites is being disposed of in an ethical and sustainable way,” Williams says.
Williams set up HydroVac with business partner and managing director Dean Stuart 17 years ago. Today, HydroVac has offices in West Auckland, South Auckland and Canterbury and works with commercial, industrial, and residential clients, offering services of air excavation, stormwater, CCTV, drain maintenance, wastewater and sewer, grease traps and converters, and – of course – hydroexcavation.
“It’s really rewarding to be at the stage of our business that we can invest the time and resources into addressing issues like sustainability, working hard to find better solutions that have a lighter impact on our environment,” says Andrew. “It was a significant investment in terms of time and capital but being sustainable and doing the right thing is important to our clients and to us.”