Our Environmental Philosophy

The Morobe Mining Joint Venture (MMJV) is committed to achieving an excellent standard of environmental performance in all its exploration and mining activities in Papua New Guinea. At MMJV we believe it is everyone’s responsibility to protect the environment. The Hidden Valley Mine, the first of MMJV’s projects to be developed, is also the first to be approved and commissioned under Papua New Guinea’s modern environmental protection regime. The Hidden Valley Mine operates under a comprehensive Environmental Management Plan, which is founded on world’s best practice.

An integral part of this practice involves an extensive onsite and offsite monitoring program by HVJV environmental staff and the facilitation of continual specialist inspections, reviews and audits of the Hidden Valley EMP by independent international organisations such as Klohn Crippen Berger and SMEC among others. This helps ensure the HVJV EMP is constantly monitored for compliance as well as provided for with alternatives to continuously improve upon.

All tailings from the Hidden Valley process plant are permanently stored in the engineered Tailings Storage Facility (TSF).

Environmental Challenges and Solutions

The mine is located in a high rainfall area with permanently flowing streams at altitudes of around 2000 metres. The year round rainfall produces substantial water run-off from the site, and particular attention is paid to water quality, soil stabilisation, waste management, and containment of tailings generated by the mine’s mineral extraction processes.

All water used in our process plant is recycled, being first treated and then re-used in the milling and metallurgical circuit. This reduces the amount of fresh water required from local water sources.

Tailings from the processing plant are treated and stored in a purpose built Tailings Containment Facility, the only one of its kind in Papua New Guinea. All mine tailings, the residues of the gold recovery process, are permanently stored in this large and stable facility. No tailings are discharged from the Hidden Valley mine. From the earliest days of mine development and construction, extensive rehabilitation and revegetation has taken place. Most of the species planted are native to the area, with a limited number of plant varieties introduced from external sources because of their particular value to the rehabilitation process. Many local people have found employment in stabilising earth banks, and planting shrubs and trees as part of this ongoing revegetation program.

The construction of a 4.5 kilometre state-of-the-art overhead conveyor to carry ore to the mill further lessens the impact of the mine on the natural environment, by partly reducing the need for trucks and haul roads.

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Environmental Studies

Very detailed studies have examined the possible impact of the mine on the river system, and on local communities living downstream of the area of operations. Baseline studies have recorded the levels of natural turbidity occurring in the streams, which are tributaries of the Watut River. Levels of suspended solids are naturally high in most PNG rivers, caused by high rainfall and run-off, erosion, landslips, gardening and other events not related to mining activity.

These studies, which include the collection and testing of aquatic life forms from the river system, and observations of forest life, contribute to a large database of knowledge relating to the natural environment close to the mine and further downstream. Environmental studies are ongoing, and will continue throughout the life of the mine. Advanced monitoring technology is employed

Cedar bridge Hydrology Station - Golden Pine

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Sedimentation in the Watut River

Sediment entering the Watut River during the mine construction period has caused concern amongst local communities. The mine transitioned from construction to operation in October 2010 and mine sediment run-off is now significantly lower due to extensive mitigation measures. These included ceasing side casting of waste rock and overburden, ongoing revegetation of exposed slopes, erosion control and storage of waste rock in engineered waste rock facilities.

The Hidden Valley mine places a high value on responsible environmental management and its relationship with local communities. As an example, the HVJV has been making voluntary garden compensation payments to communities along the Watut River for flood damage to crops and gardens, regardless of whether the damage was due to additional sediment run-off from the mine construction or from natural events such as landslips and heavy rain. To date, the HVJV has paid a total of K3.8 million to 3,700 Watut River landowners.

Aquatic monitoring

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Environmental Projects

As a contribution to the betterment of village life, HVJV has sponsored water supplies to provide clean, fresh water to village taps which delivers a more healthy, convenient and reliable water source than seasonal river flows. Other HVJV environmental programs include ongoing health and sanitation awareness.

The green credentials of the Hidden Valley Mine are further enhanced by the increasing use of hydro-electric power from the Yonki and Baiyune power stations. This greatly reduces the use of fossil fuels on site.

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Environmental Consultation and Advice,

There is an ongoing program of consultation with stakeholders, including landowners, downstream communities, and local, regional and national governments about the Hidden Valley Mine’s environmental activities and programs. An External Stakeholder Advisory Panel (ESAP) has been formed to provide the HVJV with independent and best practice advice on its environmental and related social impacts and activities.

Hidden Valley Mine is committed to minimising its impact on the environment and meeting all its environmental permit conditions.

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Our vision is to create a world class mineral province within PNG


Honesty, Integrity, Respect, Working Together, Courage, Creativity & Innovation and Commitment to our people


Discovering, developing and operating gold mines in Morobe Province to build a sustainable long term business to benefit all our stakeholders