A guide to leading practice sustainable development in mining

Table 2. Typical water quality issues for the mining industry
Mine-life stage Water quality related
activity
Exploration Erosion from temporary roads
Runoff of drilling fluids,
petroleum products from drill
pad construction and operation,
camp wastes.
Resource development and
design
Mining, minerals processing and
refining
Developing water management
plan.
Preparing EIS.
Discharge management.
Possible acid-rock drainage.
Tailings management.
Solid waste management.
Action
Initial baseline monitoring
program developed (weather
station, several water quality/
biology sites, water flows).
Baseline inventory and
monitoring at key sites, including
those in reference catchment(s),
implemented for water quality
and ecological features.
On-site monitoring (discharges,
storage and holding dams,
groundwater)
Off-site monitoring of receiving
system and reference sites
(quality, flows, biology).
Water management plan
implemented.
Rehabilitation Management of onsite water. On-going assessment of impacts.
Closure and post-mining Considering all possible future
impacts (e.g. acid rock drainage).
Continued off-site and onsite
monitoring.
Shipping of products Possible spillage, dust control Monitoring of receiving system
and reference sites (quality,
flows, biology).
The Cadia case study illustrates the importance of collecting data during the EIA
and feasibility stages of a mining project. The Cadia Hill gold mine was approved on
6 September 1996 with several conditions. These conditions related to the release
of water from Cadiangullong Dam and the maintenance of flows in Cadiangullong
Creek to provide environmental flows and as well meet the requirements of
downstream users.
Limited baseline data on the aquatic ecology and hydrology of Cadiangullong Creek
was available at the commencement of the project and additional data was collected
as part of the environmental impact studies. At the time of the construction of the
Cadiangullong Dam, empirically based processes for determining the riparian and
environmental flows needed to maintain riverine ecosystem integrity were in their
infancy in Australia. Virtually no research had been undertaken on these issues in
small upland streams.
Additional research was required to be undertaken to assess and model the
effects of changing flow regimes (drought, low, medium and flood) on in stream
and riparian environments and their associated organisms. The Environmental
Studies Unit at Charles Sturt University was contracted by Cadia to design and
carry out appropriate research to satisfy the requirements of this condition. The
researchers concluded that there was no evidence of a decline in stream diversity
and that under the range of flows available during the study period, a very high
58 LEADING PRACTICE SUSTAINABLE DEVELOPMENT PROGRAM FOR THE MINING INDUSTRY