Tailings Disposal - Mining and the Environment: From Ore to Metal - page 746

TABLE 18.6
Tailings Monitoring Programme

Parameter Purpose Method Frequency

Quantity discharged, solid: liquid ratio Assess storage capacity

Calculate water balance

Flow meter
Density meter

Continuous, compiled daily

Quantity recovered through decant
system

Calculate water balance Flow meter Continuous whenever decant system

is operating

Tailings liquor quality parameters.
e.g. pH, Electrical Conductivity (EC),
CN WAD

To assess compliance with
regulations or standards

Electronic probes (pH and EC)
Titration (CN WAD )

Depending on variability, regulations
or experience. May be from 30
minute intervals to 24 hour intervals

Size and location of decant pool,
Available freeboard

To help manage discharge
locations and decant volumes

Visual observation or measurement,
supported by completion of checklist
report and photographic records

Daily

Underdrain seepage volumes To assess effectiveness of sealing

layers and drainage system

Flow meter operating during pumping As required depending on pumping

frequencies

Underdrain seepage quality; e.g. pH,
EC, CN
Selected cations

To assess compliance, or, possibly,
to assess suitability for discharge
or re-use

Electronic probes, Titration
AAS

Monthly, more or less frequently
depending on variability and whether
toxic constituents are involved

Deformation of embankment To assess settlement and lateral

movement of embankment
that might indicate impending
instability

Precise survey of surface marker pins
Inclinometers

Monthly
More often if signifi cant deformations
are detected.

Phreatic surface within embankment To check whether or not the

system is behaving as required
To provide advance warning of
increasing pore pressures

Piezometers, design of which depends
on nature of embankment or foundation
material

Weekly or monthly

Water quality parameters: cations
and anions selected as indicators, or
as potential contaminants of concern,
or as mandated by regulation

To check whether or not
local groundwater is being
contaminated by seepage from
the tailings storage

Sampling from groundwater bores or
piezometers, followed by laboratory
analyses

Monthly or quarterly

Density and strength of settled
tailings

To help assess capacity of storage
To assess the feasibility of
upstream or centreline
construction for future embank-
ment raises

Density testing - sand replacement or
densometer methods
Strength testing by static cone or vane
shear methods, and/or by undisturbed
sampling and laboratory triaxial testing

Annually or as required

Unusual occurrences or incidents e.g.
damp areas on face of embankment,
cracks or erosion gullies in embank-
ment, springs or seeps downstream
of embankment

Possible indicators of developing
problems
Identifi cation of areas requiring
maintenance

Reconnaissance - drive-by observation.
Careful and systematic visual
observations, supported by completion
of checklist report and photographic
records

Daily
Weekly or monthly, and immediately
following intense rainfall event or
earthquake

the undertakings by the mine operator in their own documentation. Some standards of
various countries follow.
●

The Australian guidelines 'Guidelines on the Safe Design and Operating Standards
for Tailings Storage' and 'Guidelines on the Development of an Operating Manual for
Tailings Storage' both produced by the Department of Minerals and Energy, Western