Our Environment - Mining and the Environment: From Ore to Metal - page 319

economic sector is interlinked with other sectors in various ways, the economic impacts
of a mine development affect most sectors. A mine could not operate without electricity,
which may be generated from coal, while from its profits the government takes taxes and
may for example, invest in new infrastructure. The mine generates employment, attract-
ing newcomers to the project area. Increased population combined with an increase in
purchasing power stimulates growth in the services sector.

7.7 JUDGING THE STATE AND VALUE OF THE
ENVIRONMENT

If the environment is defined as a set of natural and man-made features at a given place and
time, the question arises as to how to judge the state and value of a natural resource, once
baseline surveys have helped to identify and describe these features. Three approaches
help. The straightforward approach is to apply quantitative metrics such as regulatory
standards or established scientific criteria, if they exist. The second, admittedly more chal-
lenging approach, is to apply subjective criteria to judging environmental values as are
commonly used in nature conservation. In the third approach, economic considerations are
applied to evaluate the benefits and services that nature provides.

Applying Regulatory Standards and Scientifi c Criteria

Ambient environmental standards, set by public authorities, are helpful in judging the
state of our environment. They are numerical concentrations of environmental parameters
established to support or protect a designated use of a resource in an ecosystem. They rep-
resent concentrations of parameters in an environmental medium (such as air, soil, water,
or fish tissue) that must not be exceeded, or levels of environmental quality that must be
maintained. They provide lower or upper limits within which the concentration of a given
parameter (such as concentration of trace metals) must fall to protect human health, or to
ensure long-term sustainability of an environmental resource (ADB 1998). Thus, the com-
parison of observed concentrations with ambient quality standards provides a qualitative
valuation of the environment under consideration.
Ambient quality standards are normally expressed in terms of average concentra-
tion levels over time. Some standards such as those for air quality may have two criteria
defined as averages over two time periods, often daily and annual averages. The reason for
taking averages is to recognize natural daily and seasonal fluctuations, and fluctuations in
pollutant emissions. Averaging also allows for the limits to be exceeded for a short time,
provided that this situation does not persist.
Of course, ambient environmental standards are not directly enforceable. What can be
enforced are the various emissions that lead to ambient quality levels, the prime driver of
emission standards. Emission standards are not-to-exceed levels applied to the quantities of
emissions coming from pollution sources, normally expressed in terms of the mass of mate-
rial per some unit of time. As with ambient quality standards continuous emission streams
such as flue gas emissions may be subject to two averages, a short-term and a long-term aver-
age. It is important to realize that meeting emission standards does not necessarily result in
meeting ambient environmental quality standards. Between emission and ambient quality
stands nature, in particular meteorological and hydrological mechanisms that link the two.

The comparison of observed
concentrations with ambient
quality standards provides a
qualitative valuation of the
environment under consideration.

Meeting emission standards does
not necessarily result in meeting
ambient environmental quality
standards.