Anadarko’s oil exploration drilling operations off the New Zealand coast late in 2013 involved a variety of land-based operations including support from Intergroup for liquid waste disposal.

The waste disposal operations were carried out under intense health and safety, environmental and logistical pressures.

Despite these strictures, Intergroup successfully delivered the full contract with no health and safety or environmental incidents and completed all the waste removal operations compliant to Anadarko’s performance and quality standards.

Onshore waste transport and processing

Anadarko’s New Zealand oil exploration drilling operations were centred on the deep sea drilling ship Noble Bob Douglas, which carried out a series of investigations in areas off the coast of both the North and South Islands over a three-month period late in 2013.

Three drill ship supply vessels operating in rotation transported waste material produced by the drilling operations to land for processing. Contractors servicing the vessels were under intense pressure to keep the supply vessels in service, due to the high costs involved.

Intergroup provided industrial operators and specialised equipment to:

A late change to Anadarko’s operating procedures meant that a wider range of waste materials required processing than was originally contracted. However, due to Intergroup’s extensive resources, we were easily able to handle this unexpected extended requirement.

Over the period of the drilling project, Intergroup handled more than 3000m3 of liquid waste, requiring 136+ truck movements and over 1000+ man-hours of work.

Waste materials included SBM (synthetic-based mud), oily water, dry cement powders, bilge water slops, waste oils and empty chemical drums. Some of these materials were converted to fertiliser, while oil was recycled and cleaned chemical drums went to scrap.

Meeting the resourcing challenge

A critical aspect of this contract was Intergroup’s ability to mobilise staff and equipment at short notice to undertake waste material unloading when a supply ship arrived in port. This included the need to handle 24/7 operations as required.

Usually, only one ship was in port at a time, while the others were in transit to or from the Noble Bob Douglas. However, at one point, all three ships arrived in port at the same time, putting extreme pressure on all contractors and requiring a substantial increase in our waste removal capacity.

We comfortably handled this unforeseen demand within the programme, through mobilising additional resources from elsewhere in New Zealand.

Significant health, safety and environmental hazards

Working with a variety of waste materials, in a tight working environment amongst live port operations and alongside numerous other equally time-pressured contractors servicing the same ship, meant high health, safety and environmental hazard risk. Mitigating this risk required excellent communications, sharing of hazard information and meticulous logistics management.

Paying attention to Health and safety of all personnel

All Intergroup personnel working on-site were well trained and complied with a stringent set of overlapping Health and Safety requirements, including Intergroup’s own standards and procedures, the Port of Taranaki’s compliance provisions and also the specific requirements of the ships being serviced.

Through a combination of good coordination with other contractors, careful logistics management and having skilled staff with good situation awareness, no health and safety incidents occurred.

Environmental risk management

In handling a variety of waste materials around the marine environment, Intergroup took special care that to ensure no spills occurred, to the extent of catching drips from pipe connections. Staff were constantly vigilant of any change in environmental conditions, such as deterioration in the weather, which could affect operations.

As a result of this constant attention, no environmental incidents occurred.


Watercare’s Eastern Interceptor is a large reinforced concrete cast in-situ tunnel that follows a 19km long path from Orakei to the Mangere wastewater treatment plant. It delivers two-thirds of the total wastewater flow processed at Mangere. Sections of the tunnel have been affected by corrosion, significantly reducing the durability and performance of the sewer at these locations.

We were approached by Watercare’s head contractor, BBR Contech, in 2013 to undertake blasting inside the tunnel to remove debris and degraded concrete in the preparation of application of a new protective coating.

The work inside the sewer involves a logistically complex exercise where cleaning, preparation, application of high-performance concrete and curing all take place within very short operational windows.

Working in a live sewer also presents a number of health and safety issues, including biological risks and gases. In response to this challenging environment, we designed and built an automated trolley-mounted unit equipped with ultra-high pressure (UHP) water blasters to undertake the blasting work. UHP water blasting is very efficient and results in considerable time-savings. The technology is also very effective at removing the concrete without disturbing the sewage.

Winches attached to the trolley allow the unit to be pulled through the tunnel at a controlled speed. The trolley is capable of blasting 500m of tunnel at a time although we generally operate it over stretches of 150m.

Operators stationed outside the tunnel operate the ultra-high pressure blasters mounted on the trolley via remote control. The operators can monitor progress and work quality via CCTV cameras mounted on the trolley.

Using the remote controlled trolley and the CCTV equipment substantially reduces the amount of time that operators need to spend inside the tunnel, minimising health and safety risks.

You can find more details of our wide range of infrastructure services here. Or Contact your nearest office to see how we can help


Industrial services delivery on various offshore oil facilities in the Maari and Tui oil fields are now being delivered by Intergroup as the company ramps up its services in the sector.

For example, Intergroup staff on a floating production, storage and offload (FPSO) vessel have begun a difficult cleaning operation in the ship’s forepeak area. This job, which two other contractors have previously attempted, is especially difficult because of the confined space nature of the area and the materials involved.

Using rope access and steam cleaning technology, operators have made significant progress that fully meets the client’s expectations.

Other services that Intergroup will be providing include running a blasting and painting programme for corrosion protection, ultra-high pressure (UHP) water blasting and dry blasting, as well as running quality assurance, inspections, technical support, and unique requirements such as rope access non-destructive testing (NDT).

To support delivery of the services, Intergroup will introduce new technology and equipment, such as that used for tank cleaning and sludge removal. All equipment introduced to the job will be rig safe and zone rated, to reflect safety requirements around the highly volatile working environment. The new equipment will include UHP pumps, air compressors and low-pressure water blasters.

Examples of the specialist equipment that Intergroup is deploying to its offshore oil work sites include Hammelmann and Woma pumps.

The Hammelmann is a Zone 1/Zone 2 T3 rated high-pressure pump able to operate at UHP or low pressure. Designed for use in highly hazardous areas the Hammelmann can operate anywhere on a vessel or oil rig, rather than being confined to safe zones.

Like the Hammelmann, the Woma pump is a Zone 1 certified industrial pump unit specially designed and built for offshore tank cleaning. Capable of delivering 4000psi and 25 l/min the Woma can be used across a wide range of applications on offshore oil facilities. With a built-in offshore lifting frame, the Woma is highly portable as well as powerful and able to operate in hazardous areas

Intergroup has fully qualified offshore operators trained and ready to put the Hammelmann and Woma pumps into action.

All staff on site are certified and fully accredited to the standard required for the multi-hazard wok environment and the hazardous nature of the work they’re required to carry out. This includes BOSIET, UKOOA medical certification, and UHP operator, confined space and working at heights certification.

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Auckland 2163