|
|
RGC: Project Experience
Minnova Inc. Properties
North America
- Client:
- Metall Mining Corporation
- Years of Service:
- 1992
- Project Description:
- Metall Mining Corporation, prior to finalizing the purchase of Kerr Addison's interests in
Minnova Inc. in 1992, performed a due diligence assessment of the properties and assets of Minnova.
As part of this assessment, Metall Mining required an assessment of the potential liability associated with
each property to identify the major existing and potential environmental compliance, violation or closure
concerns.
- Services Provided:
- Dr. Robertson was the Project Principal and Senior Technical leader of
the SRK
team which was retained by Metall Mining to conduct an
environmental liability assessment and to estimate closure costs of Minnova's properties. The study
included four operating mines, 10 past producers, eight advanced exploration, and four exploration sites
in five provinces and Washington state. To perform this evaluation within Metall Mining's schedule
required the mobilization of three teams, each with a diversity of skills to review and assess all major
aspects of environmental liability. Our preliminary findings and closure costs were presented to Metall
Mining and to Minnova three weeks after the project started and a final report issued three weeks
later.
- A pre-acquisition site reconnaissance was conducted to assess current and potential issues of
environmental liability. Eighteen sites were visited including were made for producing mines or former
producers (properties with major surface disturbances or accumulations of tailings and waste rock), as
well as for exploration sites with significant surface or underground development. Inspections were made
of the major mine and mill components, the property compliance data was reviewed and site personnel
interviewed. Since many of the mines recovered base metals from sulphide ores, a number of the
properties had concerns regarding the potential for acid rock drainage (ARD), particularly after closure.
This is of particular concern for older sites, as the prediction and control of acid rock drainage is a
relatively new science and requirement for mines. Therefore, much of the effort in performing the
environmental liability assessments was devoted to ARD. Closure plan options were developed to address
the major issues, with an estimate of the costs for implementation of the recommended options.
Regulatory authorities were contacted for all sites to identify any concerns that they might have.
- In assessing financial liability, compliance under current permit or regulatory requirements was
assessed and also the additional environmental liability considered likely in the near future (less than 10
years) under the prevailing regulatory trends. These were non-sampling assessments, based on field
observations and technical review of the main components at the site.
- Consequently, the liability assessments and cost estimates relied, to a large extent, on the
experience and engineering judgement of our investigation teams. The estimated closure costs were
summarized in terms of capital costs for mine, mill, mine rock, tailings and other components, as well
as for a bond amount which must be set aside to provide a perpetual fund for long term maintenance of
a site.
| |
