Environmental Remediation

Environmental Remediation for Contaminated Sites

Photo courtesy of OECD.orgOpens in new window Having defined environmental protectionOpens in new window and conservationOpens in new window from the regulatory and legal point of view, it is necessary to discuss how pollution or contaminants can be remedied if it does occur.

We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.Aldo Leopard

Although, it is impossible to prevent all chemical spills, intentional releases, natural disasters and accidents that lead to contamination, prevention is still a primary goal of most governments and industries.

This would mean that once requested by the government or a land remediation authority, immediate action should be taken as this can impact negatively on human health and the environment. The fundamental goal of remediation should be to render a site acceptable and safe for long-term continuation of its existing use and maximize to the extent practicable its potential future uses.

According to the OECD (2008), Australia is one of the highest producers of waste in the world, generating waste at a rate of over 2kg per person per day, the majority of which ends up in landfill, causing the land and soil to be contaminated with acid sulphate and other pollutants.

Often, the most visually obvious effects of acid sulfate soil disturbance are on fish and other aquatic organisms.

Run-off transport, the acid from acid sulfate soils to local waterways, exposes aquatic animals to rapid changes in pH, toxic levels of aluminum, iron precipitation, and low dissolved oxygen levels (Cappo et al. 1995). The management of municipal and industrial wastes has long been recognized as a key issue in environmental sustainability.

In view of the above, environmental remediation of contaminated land and soil must incorporate the views of the public and a review of the environmental footprint in addition to the standard factors including cost, feasibility, and protection of human health and the environment.

In the past, many exploration and production activities were developed without appropriate consideration of their environmental aspects and impacts. Operations were run in situations in which laws and regulations did not exist or if they did, they were neither adequate nor comprehensive enough. As a result, hazardous contaminated sites were created.

Such sites have been created by accidental oil spills during loading, transportation, and unloading operations, improper handling, storage and disposal of industrial wastes, leaks from aging or deteriorated equipments and greenhouse gas emissions.

The impacts of oil spills, industrial wastes and carbon emissions are not limited to the direct effect on the ecosystem; it goes a long way to affect the social welfare, aggravates poverty, population displacement, social conflict, production reduction, and also affects the profit margin of the companies involved.

As contaminated sites can ultimately lead to undesired health effects for the surrounding community and its inhabitants, appropriate actions must be taken. Hence the reason for an environmental remediation.

Significant environmental statutes that pertain to environmental remediation include:

Site contamination can occur as a result of the introduction of chemical substances to a site above background concentrations. Environmental protection of oil and gas facilities is the reason for the OPGGS ActOpens in new window. An example is thePTTEPA Montara oil and gas leak in the Timor SeaOpens in new window, off the northern coast of Western Australia.

There are several factors that must be considered when determining whether or not the presence of the chemical substances is deemed as site contamination.

A site is therefore said to be contaminated if it has a substance in it at above background concentrations, which present or has the potential to present a risk of harm to human health or the environment. The environment includes living things and their physical and biological surroundings, and interactions between these.

Environmental remediation of contaminated sites is applied in two ways:

1. by applying actions to the contamination site itself. This can lead to fixation, immobilization, microencapsulation, solidification or removal of the actual source of pollution, for example by means of decontaminating the polluted areas or surfaces, and
2. evaluating risks related to pollution exposure to people and thinking of ways of breaking the pathways between the pollution source and people. This approach might lead to evacuation, area isolation or changing land use and the local populations living habits.

The two ways mentioned above are complementary. When deciding on the actual remediation work, several different factors need to be taken into account.

As every site has its own characteristics, there is no simple quick fix. The most important thing is to understand that remediation actions need to be justified and optimized—the adopted actions must do more good than harm.

For example, increased pollution levels do not necessarily mean that the increase is harmful; some living environments are within the internationally accepted levels. Thus, evacuating or isolating areas without firm scientific grounds for it can needlessly cause distress to the people it concerns.