Worldwide, the very mention of asbestos sparks fears of deadly consequences to those exposed – and rightly so. A group of minerals made up of many small fibres, asbestos is a known carcinogen linked with a range of diseases including lung cancer, asbestosis and mesothelioma.

Since the 1990s, our understanding of asbestos and the potential health risks it can cause has greatly improved. We now know that if left buried and undisturbed, asbestos doesn’t pose a health risk. But what if your project requires asbestos to be disturbed, exposed or removed?

When asbestos fibres become airborne, the potential health risks change significantly. Stringent rules and legislation are abundant, and dealing with asbestos can be a costly exercise causing unwanted attention if not managed appropriately.

But what is the best way to manage this? In many contaminated land cases, the level of asbestos in soils is low – yet our immediate reaction is to treat it as a high-risk waste.

Asbestos was commonly used in New Zealand from 1940-1980 in various building materials. As a result, there are now increasing examples of asbestos contaminated sites being discovered. Growing population in cities like Auckland have resulted in a flurry of new building construction and infrastructure improvement – often where asbestos buildings have been inappropriately demolished or where asbestos waste was previously dumped.


Many places in the world, including New Zealand, currently treat asbestos in soil differently than all other contaminants, but why?

Asbestos-related diseases are linked to exposure to free asbestos fibres, generally at high concentrations over the long-term. But long lag times between exposure and becoming sick, growing fears fanned by media reports and an ever increasing New Zealand asbestos register is influencing the way we deal with it. Perhaps more than necessary.

With no New Zealand guidance for assessing, remediating or managing asbestos-contaminated sites, any asbestos found in soil is managed in accordance with the Health and Safety in Employment (Asbestos) Regulations 1998, developed to manage asbestos in buildings – quite a different situation to asbestos in soils.

Owners in both the management of the soil during earthworks and off-site disposal of excess spoil are under pressure to over deliver when it comes to handling this material, for fear of a mis-step under the public eye.

Up until now, low-level asbestos contaminated soil has been disposed of at a Class A landfill. These facilities use systems designed to provide a degree of redundancy for leachate containment, and collect landfill leachate and gas. Many of these measures aren’t applicable to the safe disposal of low level asbestos contaminated soil – and prove to be a costly solution for owners. Because of this, Coffey is taking a new approach that allows owners to effectively manage the risk of low level asbestos in soil, rather than disposal sites traditionally designed to deal with much higher risk contaminants.

Sometimes the simpler option is the most effective one

Safety is always at the core of what we do – which is why mitigating risks to both our people and others exposed to asbestos is our key concern.

But we also believe that with such serious consequences at stake, decisions for dealing with asbestos must be information driven – not emotive.

Instead of disposing of all low-level asbestos contaminated soils at Class A landfills, we should consider the degree of risk that actually exists. At the end of the day, our actions should be dictated by one simple question: how can we effectively manage the risk of asbestos becoming airborne?

Minimal disturbance and encapsulation are key to disposal cost savings

We know asbestos is a risk to human health when fibres become airborne, which is why we believe that often the most effective way to deal with this contaminant is to disturb it as little as possible and manage it in situ.

We’ve assisted several developers in managing risks during earthworks for redevelopment of asbestos contaminated sites using cap designs and on-going land use controls to protect future site users. A key element of these solutions has been our experts working with council to gain appropriate consent approvals.

In situ asbestos management is often feasible at a development where land use controls can more easily be enforced. But residential and commercial developments often call for soil to be removed from site. And until now, the only option has been for removed soil to be taken to a Class A landfill.

But managed fill sites are now a genuine alternative. These sights are cheaper to access and provide a simpler, more cost effective solution for the project owner. In our experience, capping and land use controls associated with many managed fill sites (disposal sites requiring resource consent to accept well-defined types of non-municipal waste, for example low-level contaminated soils) are more than enough for minimising risks of asbestos in soil – effectively cutting your disposal costs by two thirds or more.

Worksafe NZ recently endorsed the Western Australian guidelines for asbestos investigation and management. These guidelines advocate a weight of evidence approach to assessing risks associated with asbestos in soil. This takes into account laboratory data as well as other lines of evidence, like frequency and occurrence of positive asbestos results.

This method allows for more informed decision making on asbestos disposal options, and is an approach we’ve adopted successfully within New Zealand – gaining regional council approval for our client to dispose of low-level asbestos contaminated soil at a managed fill site.

By avoiding the need to use a Class A landfill for disposal, we’ve been able to save our client significant disposal fees.

How can Coffey help?

By using our expertise and ingenuity, and collaborating with our clients and regulators, we’ve delivered real cost savings on management of soil contaminated with asbestos in New Zealand.

These strategies have been reviewed and approved by the local and regional councils – with very little risk to our client.

Asbestos is an emotive contaminant that should be treated in a risk-based nature – the same as every other contaminant we are exposed to.

Our specialists have the technical expertise and track record when it comes to dealing with asbestos contaminated soils.


Anne Hellie, Associate Environmental Consultant
Warren Sharp, Environmental Team Leader

Read more Ingenuity@Coffey articles

Client name: Housing New Zealand Corporation (HNZC)
Duration: January 2013 – June 2014
Location: Hutt Valley and Porirua, Wellington, New Zealand

Coffey helped Housing New Zealand reach a seismic resistance rating of more than 33% across their property portfolio to meet national legislation and new building standards.


Housing New Zealand owns a large portfolio of residential properties.

Following the Canterbury earthquake sequence, Housing New Zealand made the decision to assess its properties across the country to determine whether they were potentially earthquake prone, as a health and safety measure. This initiative identified a number of properties in the Wellington region to be upgraded to meet acceptable national seismic standards prior to being safely re-tenanted.

We were engaged to project manage remediation activities for 46 buildings in the Wellington region. Most of these were more than 50 years old.

To manage costs and on time delivery for such a large number of properties, our client needed a streamlined approach to working with the consultant team.

Structural designs were based on a limited number of generic building types, which meant many exceptions were expected to be found once building fabrics were exposed. Custom solutions would need to be efficiently applied to deliver the project on time and on budget.


Rather than the more traditional approach where various subcontractors worked independently and reported directly to the client or delegated site contact, we became the primary point of contact for our clients. Having one source of information ensured clearer visibility across the whole project to better inform the decision making process, reduce the likelihood of lost information and relieve project pressures from our client.

As the tender process was complex, we advertised works packages in bundles of 12 properties to ensure their fast turnaround and maximise client value.

Effective communication between our client, consultants and contractors was also established from the outset. This provided a collaborative environment to resolve any structural design issues and deliver practical solutions to minimise costs and delays.


Strong collaboration and communication throughout the project resulted in pragmatic solutions to meet the required quality standards for the EPB program. 198 homes were remediated to meet acceptable seismic standards, and a large base of affordable housing made available to the region.

Read more about our recent projects in New Zealand and around the globe.

Housing NZ EQ Prone Buildings

Knowing your geo-hazards could mean your property isn’t fated to restricted development consents due to unfavorable zoning says Adam Broadbent, Senior Engineering Geologist for Coffey Christchurch. 

Many home owners missed their opportunity to submit an appeal against the Christchurch City Council (CCC) District Plan and challenge their property’s zoning.

It’s so important to understand your property’s geo-hazards resulting from the Canterbury earthquake sequence, and how they are classified in the CCC District Plan “Instability Management Area”. CERA risk profiles have been used to apply ‘potential hazard’ zoning over all properties in the Port Hills area. But had a ‘site specific’ investigation been undertaken, many properties might not have been zoned this way.

Many of the hazards in your local area can be addressed in a realistic and cost effective way. Engaging with an experienced geotechnical team will help you identify the geo-hazards of your property, provide you with a quantifiable level of risk, and most importantly help you meet legislative requirements for consent approval.

Now is the time to think about your property’s future

Under the Resource Management Act, the CCC has revised their District Plan – which upon approval will be in place for the next 10 years. The revision identifies rockfall management and cliff collapse hazard zones in an effort to reduce residential exposure to natural hazards. As a result, many living in the Port Hill suburbs now find their properties located in instability management areas.

Placing owners at a clear disadvantage, the likely impact imposed is consent restrictions, reduced property value and saleability due to unfavourable hazard zoning.

Where to from here?

Justifiably, following the Canterbury earthquake sequence there’s a heightened awareness of potential hazards including boulder roll, cliff collapse and mass land movement – so it’s important to understand your own level of risk.

If your property is on a cliff, rockfall or mass movement hazard zone 1 or 2, then certain development activities will be prohibited, or rely on a Chartered Geotechnical Engineers site assessment to progress.

However, sound geotechnical advice will help you to demonstrate that the hazards have been correctly identified and mitigated.

A geo-hazard assessment will classify your property as high or low risk. Read more…

Thanks to all who joined us for the  4th Annual Coffey Lawn Bowls Competition on Friday 13th March 2015—good job we’re not superstitious!

It was a great way to spend a Friday evening, with clients and colleagues contesting the Cup, Plate and Bowl competitions in true knock-out form.

The sun shone again… though it was touch and go for a short while as we watched the thunder and lightning drift across the horizon. The drinks were cold, the food was good and the standard of bowling was—well let’s just say, varied.

We had 22 team entries this year which is a record turnout—a great effort was made by everyone, particularly those who dusted off and donned their fancy dress costumes.

Between rounds we broke for refreshments and the corner–to–corner competition to win a bottle of Grants whisky—and didn’t that bring out our competitive natures!

Results were as follows:

  • Cup winner: City Care Ltd
  • Plate winner: HEB Construction
  • Bowl winner: Ministry of Education Team #2
  • Wooden spoon: Southbase / Thiess
  • Best dressed teams: Southbase SWAT team, Christchurch City Council Pirate Bad Boys, CERA’s Hawaiian Mafia
  • Best dressed individual: Gordon McGregor, the US Convict

Thanks also to our friends and hosts at Burnside Bowling Club, and also for not laughing at our bowling expertise too openly.

We’re already looking forward to next year…

River restoration work as part of Te Papa Ōtākaro/Avon River Precinct project is nearing completion – ahead of programme.

Project managed by Coffey, contractor City Care has removed more than 5,000 tonnes of liquefaction sediment between the bridges of Colombo and Barbadoes streets, with gravel cleaning and preparation of areas to accommodate planting.

Aquatic scientists have already observed the return of native species to the river as a result of the revitalisation work.

Shelley McMurtrie, of EOS Ecology, says:

The focus of the in-river works was to improve the health of the river. The shape and nature of volcanic rock lent itself particularly well to the ecological-design criteria, providing undercuts and cavities for longfin eels – a habitat that was previously limited along the river.

The ecological benefit of the volcanic rocks is already evident, with large eels found in residence in the newly created eel cavities.

ARP_InRiver_Planted Fresh Plains_b

There are still a few places left for teams or individuals to join our lawn bowls tournament on 13th March at the Burnside Lawn Bowls Club. Don’t miss out on the chance to join the coveted ranks of Coffey lawn bowls champions.

Please RSVP to Tess Martin as soon as possible if you are interested in taking part. If you don’t have a team of four we can organise one for you.

Tess Martin
t: 03 336 5402

2012 winners: Structex

2013 winners: Christchurch International Airport Ltd

2014 winners: Pedersen Read

It’s that time again and here in the Christchurch office we are busy preparing for our annual afternoon of bowling and socialising at the Burnside Lawn Bowls Club.

Like previous years, we will play a knock–out tournament with teams of four and prizes for winners, losers, and the best–dressed.

Please RSVP to Tess Martin as soon as possible with your team details to secure your spot in this year’s tournament. If you don’t have a team of four we can organise one for you.

Tess Martin
t: 03 336 5402

Please confirm the names of your team members when you RSVP.

Click here to download pdf invite.

Coffey Lawn Bowls invite_2015


Get every new post delivered to your Inbox.