Heavy
machinery - Wellington
City Council
Summary
In 2003 two significant pieces of heavy machinery were purchased by council, a road sweeper and a machine to assist in the replacement of underground pipes. Both purchases involved significant capital expenditure and council recognised the opportunity to ensure that environmental considerations were taken into account in the purchase of these machines.
Key drivers
The key drivers for the procurement of heavy machinery that reduces environmental impact is increasing ratepayer expectations:
- that emissions to air are minimised and suppressed wherever possible,
- that underground work does not disturb the environment, and
- that waste to landfill/cleanfill is minimised.
Project detail
In the case of the road sweeper, a review of the market revealed that there were only two sweepers available that would meet the requirements of Wellington City. Both were evaluated, and included in the evaluation criteria was a requirement of consistency with the principles of Wellington City's EFP policy. One sweeper was clearly identified as superior in this and other respects, as emissions into the atmosphere and fuel consumption were reduced.
A road sweeper with a regenerative air system was procured. Although more expensive than the competition it expels cleaner air. Council chose a more expensive replacement road sweeper because regenerative or recycled air is used to collect debris and to pack it into the hopper over a "loop of air". Because the air remains within the sweeper and passes through a filtering screen, virtually no dust or polluted air is vented into the atmosphere.
A trenchless technology machine was procured that removes the need to dig holes in the ground when replacing pipes. The environmental benefits of this machine were the reduced need to cart tonnes of waste to cleanfill or landfill and a reduction in the need for virgin material to be quarried for reinstatement.
Key challenges
The purchase of both machines required additional up-front expenditure that presented the key challenge. The expected benefits (environmental and other) were presented to management who approved the additional expenditure in both cases.
The road sweeper was not only environmentally superior, but also able to sweep at a faster rate, improving productivity and causing less traffic disruption. It can also be used to duct sump drains, meaning it can be multi-tasked, saving another vehicle from being purchased.
The trenchless technology machine also had a number of additional benefits as well as the environmental benefits, including a reduction in public and traffic disruption, underground and overhead service interruption and reinstatement quality. The trenchless technology machine also means that council can work in close proximity to neighbouring pipes, cables or buildings.
Financial as well as non-financial improvements are now being reported.
Outcomes of project
Both items have very high profile and there has been significant industry interest.
The road sweeper now picks up around 35 kg/km of waste, an improvement of approximately 50%. This improvement means that stormwater pollution is reduced. Improvements to air pollution and fuel usage have not been measured.
Additional to the environmental benefits, the new road sweeper has also resulted in increased productivity as its increased speed means that it can cover twice as much distance. The Residents Satisfaction Survey had also indicated that residents believe the standard of road sweeping has improved. As a result, Wellington City Council intends to purchase another similar sweeper and dispose of two older vehicles.
As well as the environmental benefits, the trenchless technology machine has resulted in productivity improvements of between 25% and 50% over open trenching, fewer complaints from residents about pipelaying (only one complaint has been received), lower landfill fees (due to reduced dumping) and no quarry purchases.
