Recycling concrete waste: the state should make the first move

An interview with Richard from Mapei Magazine 13/11/23

Richard Amadio, Director of PumperDump: Environmental awareness in Australia is still very low with traditional disposal methods still being employed

— How high is the level of awareness in your geographical area regarding the environmental impact of returned concrete and washing water slurry?

I believe that in Australia the importance placed on waste streams, and particularly on cleanly collecting and recycling concrete waste and concrete washout, isn’t yet high enoughon anyone’s list of priorities. The current focus on material and labour costs in the built environment is distracting from current opportunities in the circular economy that could offer savings in different areas. Whilst the carbon intensity of cement and concrete production is very high, this lack of concern around concrete waste is accentuated because builders can easily and simply go and buy Green Credits to tick the environmental boxes. This practice creates inadequate incentives which act as a major barrier to progress.Builders are still happy to line concrete washout trays and blow back bins using plastic and tip the dried concrete into the on-site skip bin, comingling it with other building waste. Concrete contaminated by plastic greatly reduces the quality and quantity of what can be recycled or considered for upcycling into new concrete.The washout slurry water is allowed to slop around and go wherever it runs, creating slip risks for workers and environmental run-off risk. The slurry part of the washout process isn’t even considered as a resource for the circular economy!


— In your opinion, what is the most important factor to be able to increase the usage of recycled aggregates in new concrete?

We believe that there are numerous factors needed to increase the usage of recycled aggregates in concrete and it starts with the prime driver, mindset. The mindset shift required will be assisted by policy, regulation and enabling technology. Policy will build awareness, regulation will create incentive and industry actors will undoubtedly then find the investment needed to innovate and collaborate to go forward. Clean waste streams, new systems, infrastructure and processes will follow to deliver upcycled concrete that uses significant proportions of recycled aggregate.



PumperDump has been operating in Sydney, Australia over the past 20 years providing solutions that assist in lowering the environmental impact, costs and safety risk of concrete waste. Sustainability has always been at the forefront of our business principles, driving further innovation and development of new systems for the industry, including the latest patent-pending 5 m3 blowback bin. PumperDump is member of The Green Building Council of Australia which has had a major role in educating, bringing people together, and helping develop new standards for the construction industry.

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Obligations of the concrete pumping contractor

The concrete pumping contractor has a responsibility to ensure that all staff and/or subcontractors act in ways that do not cause environmental harm through spillage or leakage of concrete. It is the responsibility of the concrete pumping contractor to ensure concrete residue and/or washdown residue from their activities does not contaminate drains or waterways. Clean-up of all equipment, including the receiving hopper, pipelines and hoses, must also be done in a manner that does not contaminate drains or waterways. 

Wash-down water produced during clean-up of equipment must be disposed of in a manner that does not and will not contaminate nearby drains, waterways or soil. It is the responsibility of the concrete pumping contractor to manage the disposal of excess concrete and wash-down water generated during the pumping and clean-up operation. Disposal to the sewer system is not permitted without prior consultation with the local sewage authority. 
Concrete pumper operator


Proper management during the pumping of concrete can minimise the risk of any detrimental impact on the environment.


• for concrete pumping contractors working on construction sites
• for site managers overseeing concrete-pumping activities

Best management practices

  • Where possible, concrete pumping equipment should be set up on the construction site. This reduces the potential of leakages from hoppers, hoses and fittings that could contaminate the stormwater system. 
  • Ensure adequate protective screens are erected around the pump area to prevent concrete splashing into street gutters or stormwater drains.
  • Where possible, ensure the pumping of concrete occurs at a location on the site where any spillage will not contaminate the stormwater system.
  • Where a concrete pump is located on a roadway or footpath where excess material could enter the stormwater system, appropriate bunding to trap spilled material should be installed. Portable concrete collection units (plastic or metal trays or receptacles) should be placed under pumping equipment to collect any spilled material during works (see figure 2).
  • Hoses, hoppers, wheelbarrows and other equipment must be washed in the site wash-down area after all excess material has been removed by hand.
  • Excess and residue concrete from the hopper and line should either be collected and sent back with the delivery truck or placed in the site’s designated concrete
  • masonry recycling receptacle.
  • To minimise the amount of wash-down water generated, scrape excess concrete residue from the hopper before washing. Do not wash out the hopper directly into the street gutter.
  • It is the responsibility of the concrete contractor to properly manage the disposal of wash-down water generated during the cleaning process. Options for collection, treatment and disposal of wash- down water should be discussed with the site manager.
  • Wash-down water from the hopper must not contaminate the stormwater system. The wash-down area should be used only for small volumes of wash-down water and is not to be used as a disposal point.
  • Mud, soil and stones carried off-site are regarded as pollutants. Therefore, tyres and undercarriages must be clean before vehicles leave the construction site.
Inspection and maintenance
  • Inspect and maintain the machinery regularly to minimise leaks and drips.
  • Pollution controls should be in place before concrete is pumped. The concrete pump contractor should inspect pollution controls to ensure they are adequate, and should liaise with the site manager if there are any problems. •The site or project manager or delegate must maintain vigilance during the work activities to ensure that pollution control procedures are being followed.
  • Placing equipment or material where it is likely to pollute the environment may result in on-the-spot fines or prosecution.
Get in contact with one of our field experts for a more efficient, cost-effective and environmentally friendly solution at 1300 366 668 or by using the PumperDump App (App Store) (Google Play) 

Ref: Extracted from the NSW Government’s Environmental Best Management Practice Guideline for Concreting Contractors
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