Risk management can be defined as the culture, processes, and
structures that are directed towards the effective management of
potential opportunities and adverse effects (AS/NZS 4360:1999).
This is a broad definition that can quite rightly apply in nearly all
fields of management from financial and human resources management
through to environmental management. However in the context of
contaminated sites, risk management can be taken to mean the process of
gathering information to make informed decisions to minimise the risk of
adverse effects to people and the environment.
Risk assessment involves estimating the level of risk – estimating
the probability of an event occurring and the magnitude of effects if
the event does occur. Essentially risk assessment lies at the heart of
risk management, because it assists in providing the information
required to respond to a potential risk.
In a resource management setting, environmental risk assessment may
be used to help manage, for example:
- natural hazards (flooding, landslides),
- water supply and waste water disposal systems, and
- contaminated sites.
Human health risk assessment is one form of risk assessment, focusing on
assessing the risk to people and communities from hazardous substances
or discharge of contaminants.
Ecological risk assessment is another form of risk assessment that
can be used to assist management of risks to ecological values.
The focus of risk assessment for contaminated sites is usually human
health, as a large proportion of the known potentially contaminated
sites are located in urban areas. However, where valued natural
environments are present, the focus of ecological risk assessment is on
assessing the risks to plants, animals and ecosystem integrity from
chemicals present at or discharging from a contaminated site.