Tailings Disposal - Mining and the Environment: From Ore to Metal - page 745

A particular concern with tailings storages is that they are generally required to maintain
their integrity in perpetuity, regardless of future changes in climate, surface drainage, land
use and other conditions that may not be foreseeable at present. Most onshore tailings stor-
ages are constructed above the surrounding landscape, which means that they are subject
to long-term degradation by wind and water erosion. It would be preferable for long- term
integrity, if tailings could be placed in below-grade storages in mined out voids or in areas
subject to aggradation rather than erosion. However, opportunities for such storages are
relatively uncommon.
To maximize the ongoing integrity of tailings storages, it is clearly benei cial if the
i nal tailings surface can be rehabilitated to support a productive land use. Once this is
achieved, the new users have an incentive to manage the area, maintain surface drainage
and control erosion, as they would for any other area. Appropriate and effective rehabilita-
tion to create a sustainable, economically productive land use, is therefore the most impor-
tant means of ensuring long-term integrity. This is discussed in more detail in subsequent
sections including Chapter Twentyone.

A particular concern with tailings
storages is that they are generally
required to maintain their
integrity in perpetuity.

Monitoring

Monitoring of tailings disposal operations and storages has several purposes, including:
●

Determining whether the tailings discharged to the storage have the same character-
istics as predicted in the feasibility and environmental studies, and if not, whether the
differences require changes in design or operating procedures;

●

Determining whether or not the structures are performing as intended;

●

Providing early warning of the development of conditions that could lead to unwanted
events;

●

Measuring densities achieved so that capacity calculations can be rei ned;

●

In the case of staged construction, providing data for the design of subsequent
embankment raises;

●

Identifying areas or installations requiring maintenance or repairs;

●

Providing feedback to improve management;

●

Measuring the environmental effects of the operations, particularly the quantity and
quality of seepage water.

Table 18.6 shows a typical monitoring programme for a tailings disposal operation.

Audits

For any major tailings storage, 15 m or more in height, it is advisable (and in many coun-
tries mandatory) to have the design checked by a suitably qualii ed and experienced inde-
pendent third party. It has also become normal practice for audits of active tailings facilities
to be carried out at regular intervals, usually semi-annually, annually or bi-annually,
depending on the circumstances. These audits, which are best carried out by the same tail-
ings expert who was responsible for the original design, involve a detailed inspection of all
tailings facilities, discussions with operating personnel, review of all monitoring records
and, in some cases, additional testing or sampling. Tailings facility audits may continue
into the post-closure period until such time as closure criteria are achieved.
Independent audits should commence with a review of the design and operation of the
facility against the standards as set down by the regulators of the country in question and

For any major tailings storage,
15 m or more in height, it is
advisable to have the design
checked by a suitably qualifi ed
and experienced independent
third party.