Environmental Risk Assessment

Environmental risk assessments have become central to the regulation of many industrial sectors, processes, products and services. Past events have demonstrated that we cannot effectively manage that which we do not understand, and that effective management of environmental risk requires their proper characterisation and communication.

Risk management has also gained importance in commercial decisions, as it is recognised that environmental liability can present a significant source of risk to company finances, reputation and CSR commitments.

Although risk assessment methodologies may differ depending on specifics such as the applicable legislation, site location and commercial activity or process, the underlying principles remain largely the same. This allows a common approach to be applied to diverse situations and issues ranging from flooding to radiological contamination, and provides a framework for consistent communication of results to stakeholders.

Adeptus undertakes a range of environmental risk assessments which meet the requirements of regulatory regimes concerned with the actual or potential release of chemicals, particulates or biological agents into the environment, or the occurrence of physical hazards such as fire or flooding.

Our tiered or iterative approach to risk assessment ensures that cases where a simple screening assessment provides the necessary degree of confidence, no unnecessary work is undertaken.

In the case of significant risks, the initial screening assessment may not be sufficient to enable a decision. Here, further assessment may be undertaken to fully characterise risk, or alternatively to derive a threshold concentration below which risks are acceptable.

• Surface Water Risk Assessment
• Groundwater Risk Assessment
• Dispersion Modelling
• Environmental Fate, Behaviour and Toxicology
• Air Emissions Risk Assessment
• Effluent Discharge and Sanitary Pollutant Risk Assessment
• Landfill Leachate Risk Assessment
• Direct toxicity assessment (DTA)
• Ground Gas Risk Assessment
• Infiltration Risk Assessment
• Bioaerosol Risk Assessment
• H1 Risk Assessment
• Contaminated Land Risk Assessment
• Fire Prevention Plans
• Detailed Modelling

Objectives of Environmental Risk Assessment

There is growing recognition of the need to ensure that natural systems are not impaired by the vast range and quantity of substances currently discharged to air water and land. This is due to both the importance of ecosystem function, and the ability for ecosystems to act as early indicators for possible impacts on human health. Increased public awareness of ?man-made? chemicals can also lead to concern that the mere presence of such substances equates a risk to human health or the environment, which is not typically the case.

In the case of existing soil contamination or groundwater contamination, risk assessment provides a basis for setting remedial objectives or clean-up standards, as well as for enforcement action by the regulators. Risk assessment is also crucial in predicting the future environmental distribution, persistence and toxicity of substances such as industrial effluents, pharmaceuticals, petroleum products, gaseous emissions and mine tailings.

The potential future risks from newly developed chemicals, or those being produced/discharged in increasing quantities is also routinely assessed by environmental distribution and toxicity modelling.

Equally, naturally occurring chemicals can be present at elevated concentrations due to the effects of human activity, potentially leading to toxic effects in organisms, ecosystems and humans. Impacts on human health can occur via direct environmental exposure, or indirectly via the food web.

Under specific circumstances, products designed for application to land may also present excess risk of environmental damage. Misapplication of fertilisers as well as pesticides can lead to pollution of waterways, with adverse impacts including damage to fish stocks, algal bloom and eutrophication.

Environmental Risk Assessment Methods

An environmental risk assessment generally comprises following stages. Each of these may be relatively simple and straightforward, very detailed, or somewhere in between; the degree of complexity will depend on the specifics of the situation under evaluation.

Problem Definition

The problem to be addressed in the risk assessment may have been defined at the outset, and such requirements are often made obvious by the regulator or applicable government guidance. However, where things are less clear, only by ensuring the right questions are asked can the output from the risk assessment be relied upon. An initial conceptual model would typically be developed at this stage of the assessment.

Hazard Identification

Hazards relevant to the assessment may include one or more chemical, physical or biological agents with the potential to lead to harm or cause adverse affects. These should be identified, and consideration given to secondary hazards such as those associated with flooding.

Consequences / Exposure Assessment

The range and severity of potential consequences associated with each hazard should be identified at this stage, and their potential magnitude described either qualitatively or quantitatively.

In the case of a chemical agent, exposure assessment is used to estimate the degree to which a receptor may be exposed to the agent. Exposure may be quantified as a concentration in air, soil, water or other media, or using a toxicological value such as internal dose or bioavailable fraction.

Contaminant concentrations may be available from laboratory analysis of contaminated media samples, allowing for relatively simple risk screening against predetermined standards.

Where final or equilibrium contaminant concentrations are not known, contaminant physical chemical properties are used the to model partitioning between air, water, soils, sediments and biota. This allows calculation of dispersion, residence times, persistence and a predicted environmental concentration (PEC).

Probability / Effects Assessment

The likelihood of an event occurring is generally expressed in terms of either a probability or frequency. In the case of chemical exposure, various toxicity data are analysed and statistical procedures may be utilised to evaluate the relationship between any ?dose? of a substance and the toxic response or harm caused. This is referred as the dose-response relationship.

The outcome of this stage is either an estimation of toxicity at the PEC derived from the exposure assessment, or a predicted no [toxic] effect concentration (PNEC).

Risk Characterisation

In the final step, all of the above factors are considered together. Assessment of likelihood and severity of any adverse effects will allow risk to be characterized quantitatively, qualitatively or both. Ultimately, the degree of risk that can be deemed acceptable will depend on the sensitivity and importance of the situation or receptor in question and the regulatory regime under which it falls.

As environmental risk assessment consultants we have extensive training and experience in the application of scientific data and principles to real world situations. We works with many organisations and stakeholders to deliver pragmatic, commercially aware environmental risk management and reduction solutions.