The Range of Environmental Concerns - Mining and the Environment: From Ore to Metal - page 530

Cooling water is used in various mine processes for the purpose of removing heat from
equipment, process operations and materials. Typically, spent cooling water is combined
with other efl uent streams such as a tailings slurry discharge to a tailings pond (e.g. pro-
cess efl uent) or mine water stream, prior to discharge to the environment.
Mine water results from the dewatering of underground or open pit mining operations.
It is typically pumped from the mine and either added to the process water supply or dis-
charged through settling ponds or combined with process efl uent.
Seepage comprises water discharged to the environment by seepage from waste man-
agement areas (e.g. tailings ponds or waste rock dumps) or wastewater impoundment
areas (e.g. clarii cation or mine water ponds).
Storm water from a mining operation comprises surface runoff from rainfall, snow-
melt, and natural drainage. Storm water discharges associated with mining operations can
include but are not limited to drainage from mine and mill sites; drainage collection ponds;
material handling areas; raw material storage sites; and waste disposal areas, including
waste rock and overburden dumps. Typically, drainage is diffuse, with a large number of
discharge points to the environment. In many projects, storm water is collected and stored
for use in mine processes. In other cases it is discharged to the environment after i rst pass-
ing through one or more settling ponds.
Other efl uent streams on a mine site include sanitary wastewater discharges, emer-
gency overl ows from wastewater impoundment ponds, and backwash waters from pota-
ble water treatment plants.
Acid rock drainage also counts as mine efl uent, and will be discussed in more detail in
the following section.

Typically, drainage is diffuse, with
a large number of discharge
points to the environment.

Seepage

Creek

Effluent Treatment
Plant

Final Discharge Point

Polishing
Pond
Mine Water

Settling
Pond

Storm Water

Tailings
Basin

Mine Water Ponds

Tailings
Pipeline

Process
Water Mine & Mill

Storm Water

Low Grade Ore
Stock Pile

Overburden
Dump

FIGURE 13.6
Typical Mine Site and Effl uent Streams

Open
Pit

Storm Water

Waste Rock
Stockpile

River

In mining, water is both friend and foe.
Water is consumed in large quantities
as process water to extract minerals.
It can also be the most devastating dis-
ruptive force both from the standpoint
of its physical impact as well as
a carrier of unwanted contaminants.
Source:
Adopted from www.ec.gc.ca

Water Treatment
Plant

Storm Water

Lake

Creek