Industry warned to come clean when using concrete
Industry warned to come clean when using concrete
North Shore City Council is targeting the construction industry, in particular concrete placers, cutters, pumping contractors and suppliers, in its latest pollution busting programme to reduce the amount of concrete and other toxic products from entering the city ' s waterways.
The lime component of wet concrete slurry dissolves easily in water ' burning ' and killing fish, insects and plants much like acid does, and was the cause of 22 per cent of incidents attended by the council ' s pollution prevention officer, Rowan Carter, over an 18-month period.
The programme aims at educating subdivision and building development site workers and contractors about how to prevent concrete-contaminated water and slurry from entering the city ' s stormwater system and so preventing streams, lakes and beaches from becoming barren and lifeless.
Mr Carter says while site and company managers are usually aware of their environmental responsibilities, the message often does not filter down to the person doing the work.
" It appears there ' s a general lack of training when it comes to workers ' understanding of how to dispose of concrete and similar products safely. Often they are completely unaware of the impact their actions will have on stream, lake and beach water quality if the run-off goes down a stormwater drain, " he says.
" They don ' t realise that their fishing trips will be far less successful in the future if they keep polluting the water the way they do. "
Tips for concrete placers:
* The small amount of sediment washed away during the concrete curing process is highly alkaline. All wash water and slurry produced, during the curing process must be diverted to unsealed ground (away from protected trees), an excavated pit or grassed area where it can soak into the ground, or be contained and removed for disposal off-site. * * The process of exposing aggregate on concrete surfaces produces a highly toxic waste stream. When washing exposed aggregate the sediment and wastewater must be diverted to an unsealed or grassed area (away from protected trees), or to an excavated pit where it can soak into the ground, or be contained and removed for disposal off-site. This also applies to acid washing.
* There should be an unsealed area on site designated for washing concreting equipment down, and this area must prevent run-off from entering the stormwater system. If an appropriate unsealed area is not available, wash water and slurry must be collected in a container for appropriate disposal off site. * Construction companies can be held liable for the actions of their workers and contractors who do not follow the rules and regulations for managing wet concrete discharges. Everyone must be aware of his or her responsibilities.
Tips for concrete cutters: * All concrete waste produced by wet cutting (no matter how minor) must be removed by either vacuum or submersible pump in a blocked off cesspit unless it can be safely diverted to unsealed ground. Concrete residue generated by dry concrete cutting must be collected after cutting and disposed of appropriately. Tips for concrete suppliers and pumping contractors: * Chutes, pump hoses, pumps and other equipment must be washed out in a designated and contained area on site away from stormwater drains and protected trees. If there is not an appropriate area on site, the site manager should be asked to create one. Alternatively, wash equipment to a barrel or other container and dispose of the washings appropriately e.g. back at the batching plant.
North Shore City ' s compliance and monitoring officers who keep an eye out for poor construction practice including the management of concrete run-off and the blockage of stormwater drains from concrete build-up, will be working closely with Rowan Carter to ensure the message gets across.
Those who do not respond to the council ' s educative approach can expect enforcement action and for serious offences, fines of up to $200,000 or up to two years in jail.
Council contractors, who must manage and control substances harmful to the environment under the terms of their contracts and in compliance with Resource Management Act and Auckland Regional Council requirements, will also be under scrutiny and appropriate action taken if they break the rules.
The council ' s works and environment committee chairperson, Joel Cayford, says this crackdown is a significant step in addressing this aspect of the city ' s stormwater quality issues.
" We need
to encourage the whole community to take responsibility for
minimising stormwater effects. Concrete by-products are
poisonous. The council will be actively pursuing those who
don ' t properly manage contaminated water that can flow
off setting concrete, and those who knowingly tip concrete
waste products into the natural environment, " says