Media Release

Rock fall barrier demonstrated at Stockton Mine

10 June 2005

A 4 metre-high rock fall protection barrier has been on show to community representatives at Stockton Opencast Mine, north of Westport, as part of Solid Energy's proposal to mine coal along the Stockton ridge.

Solid Energy senior management and staff, along with members of the Stockton Consultative Group, representatives of the West Coast Regional Council, Department of Conservation and Buller District Council yesterday attended a demonstration of the type of barrier that the company plans to install, as one of a number of measures, to stop rocks and debris falling down the slope into adjoining Department of Conservation land, during mining of the ridge within the Stockton Coal Mining Licence (CML).

Solid Energy has finalised the technical approach for this work, designed to minimise impacts outside the CML area. The proposed measures include:

Stabilising large unsupported blocks at the top of the slope prior to blasting, using rock bolts, cable anchors, mesh and shotcrete.
Specialised blasting techniques engineered to control vibration and minimise ground movement; monitoring of blasts to assess and refine techniques.
Water management - to ensure drainage of run off back into the CML area for treatment, along with continuous monitoring of streams in the surrounding catchment.
Detailed slope and environmental monitoring programmes.

As a final control a 4 to 7 metre high rock fall protection barrier will be erected on the coal floor. During mining, on the down slope, a 4 to 8 metre berm (bench cut), will be constructed, where terrain allows, to contain loose rocks and provide a path for any contaminated mine water to run back into the Stockton CML.

Solid Energy estimates around 5 million tonnes of high value coking and other coal at Stockton borders and is within the CML in three areas known as Mt Augustus/A Drive, Mt Frederick and Rockies.

Solid Energy Chief Executive, Dr Don Elder, says: "We completely understand the concerns of the local community about the potential impacts of mining along the Stockton ridge - the impact on flora and fauna, the visual impact during mining and the cultural impact of permanent changes to the topography, and the potential for rock and water impacts on the adjoining DoC land.

"We are also in discussion with DoC about minimising the effects on flora and fauna and expect to release more information about this in the next few weeks. We are also talking with local iwi, Ngati Waewae, about their concerns and are committed to carrying out this work in such a way that the final topography will reflect the natural lines of the existing landscape.

"Yesterday's demonstration is part of a commitment to discuss with our local communities our plans for mining along the Stockton ridge both safely and with minimum impacts."

During the demonstration several rocks, weighing between and 1 to 2 tonnes, along with a 7 tonne boulder, were rolled into the 30-metre long demonstration barrier currently erected in the Webb East area of the mine. The barrier has already been tested extensively on site over the last month and certified to a 1000kJ impact without failure.

Rock fall protection barriers have been used extensively over the last 50 years in Europe and North America, particularly on ski fields and to protect roads traversing mountainous terrain. A similar rock fall barrier has been erected above the state highway along the Kaikoura Coast, the first in New Zealand. The design, layout and anchoring of the barriers takes into account that they are mostly installed in difficult, steep and remote terrain.

The ridge project has been peer reviewed by Dr Raymund Spang, an independent leading world expert on rock slope stability and rock fall mitigation. Dr Spang's German-based company has worked on rock stability projects throughout the world including mitigation projects for California's State Highway 1 and Japan Railways. Solid Energy plans to start mining the Stockton ridge later this year,

For further information contact

Vicki Blyth,
Communications Director,
Solid Energy New Zealand Ltd,
Phone 03 345 6000,
Mobile 021 670 250,
Email vicki.blyth@solidenergy.co.nz

Links referenced

vicki.blyth@solidenergy.co.nz: mailto:vicki.blyth@solidenergy.co.nz?subject=enquiry from your website

Location http://www.coalnz.com/index.cfm/1,209,588,0,html