Sick water?

In many developing countries more than 70 per cent of in-

dustrial wastes are dumped untreated into waters where they

pollute the usable water supply (WWAP, 2009). Industrial dis-

charge can contain a wide range of contaminants and originate

from a myriad of sources. Some of the biggest generators of

toxic industrial waste include mining, pulp mills, tanneries,

sugar refineries, and pharmaceutical production.

In many instances wastewater from industry not only drains

directly into rivers and lakes, it also seeps into the ground con-

taminating aquifers and wells. This pollutes water supplies and

in developing countries often goes undetected, as monitoring

is expensive. Even if it is detected, remediation often does not

occur as the source of the pollution must be addressed and

decontamination carried out at the same time, which can be

extremely difficult.

Mining has traditionally been a major source of unregulated

wastewater discharge in developing countries. Tailings from

mining operations can contain silt and rock particles and sur-

factants. Depending on the type of ore deposit being mined,

tailings can also contain heavy metals like copper, lead, zinc,

mercury and arsenic. The contaminants in mine waste may be

WASTEWATER AND INDUSTRY

carcinogenic or neurotoxic to people (e.g. lead and mercury) or

extremely toxic to aquatic organisms (e.g. copper). There are

many examples of persistent environmental damage caused by

the discharge of toxic mine waste. In Papua New Guinea for ex-

ample, companies discharge millions of tons of contaminated

mine waste into rivers from the Ok Tedi, Porgera and Tolukuma

mines (Christmann and Stolojan, 2001).

The food and agriculture processing industry can also be a

major producer of wastewater particularly organic waste with

high biochemical oxygen demand (BOD). BOD measures the

amount of oxygen used by micro-organisms like bacteria in

the oxidation of this material. Low oxygen levels or even an-

oxic conditions may result if large amounts of organic waste

are discharged into waterways. Slaughterhouses may produce

water polluted with biological material such as blood contain-

ing pathogens, hormones and antibiotics.

Cooling waters used in industrial processes like steel manufac-

ture and coke production not only produce discharge with an

elevated temperature which can have adverse effects on biota,

but can also become contaminated with a wide range of toxic

substances. This includes cyanide, ammonia, benzene, phe-

Water is an important requirement in many industrial processes, for example, heating,

cooling, production, cleaning and rinsing. Overall, some 5–20 per cent of total water

usage goes to industry (WWAP, 2009), and industry generates a substantial propor-

tion of total wastewater. If unregulated, industrial wastewater has the potential to be a

highly toxic source of pollution. The vast array of complex organic compounds and heavy

metals used in modern industrial processes, if released into the environment can cause

both human health and environmental disasters. Industry has a corporate responsibility

to take action to ensure discharged water is of an acceptable standard, and accept costs

of any required clean up. The most cost-effective solutions usually focus on preventing

contaminants from ever entering the wastewater stream or developing a closed system

of water use. Industry can also benefit from access to cleaner water resources with fewer

impurities, as impurities can add costs to the production processes.