Risk Assessment

 

Risky Business

The quantification and management of “risk” forms the basis of many environmental regulatory programs. Therefore, rigorous and defensible risk assessment is critical. But risk evaluation must also be sensible. GeoInsight has the experience required to assist you with evaluating current and future risk to human and ecological receptors. We are frequently asked to provide a “second set of eyes” to evaluate ongoing actions and identify alternative approaches to achieve strategic project endpoints and site closure requirements needed to achieve a condition of “No Significant Risk.” Often, we are asked to enhance the performance of remedial response actions conducted by others, when those actions, originally intended to achieve a level of “No Significant Risk,” have reached a point of diminishing return.

 

The Conceptual Site Model: Your Key to Success

The key to completing an effective and successful risk assessment is developing a comprehensive understanding of the site and surrounding areas and the nature of the release(s). This process involves the development of a conceptual site model (CSM). The CSM, which is developed during site characterization activities, tells the story of how a release occurred, what the release has affected, and how the release is likely to behave over time. As the CSM evolves, we begin the process of quantifying the relative levels of risk associated with a project. Our experts will:

  • Evaluate applicable regulatory program and risk assessment requirements
  • Identify impacted environmental media
  • Identify the contaminants of concern (COCs) and evaluate their physical and chemical properties
  • Identify potential preferential pathways, routes of exposure, and potential hot spots
  • Assess potential effects of COCs on human health, public welfare, and the environment
  • Identify the current and reasonably foreseeable future uses of an affected property
  • Determine sensitive human and ecological receptors, and conditions that may pose an immediate or imminent risk
  • Quantify risk levels for receptors and identify applicable standards, and
  • Summarize the results of the risk assessment process in a concise, easy-to-understand report.

 

Risk characterizations performed by GeoInsight typically fall into the following categories:

We conduct baseline risk characterizations to quickly evaluate potential risk associated with current conditions. At many sites, a baseline risk characterization clearly shows whether remedial actions will be necessary to reduce the risk inherent with the impacts present. At sites with limited contamination, a baseline risk characterization can:

  • Identify current conditions
  • Assess the potential that remedial actions will be necessary, and/or
  • Evaluate the effectiveness of historic response actions conducted at the site (or an adjacent property).

When a site is subject to an established regulatory program that includes risk/remedial standards, a standard-based risk assessment is often acceptable. These programs typically rely upon conservatively-developed generic risk criteria developed by regulators. We then use the criteria to help responsible parties assess risk and conduct remedial activities to achieve a level of “no significant risk” and site closure.

 

Usually, this approach is used to address relatively localized areas of impact and
non-complex release sites. At some sites, the use of the generic risk standards provides certainty with regard to achieving regulatory closure, but for others, the use of generic risk standards may result in the need to conduct remedial actions at a level greater than would be required based upon a site-specific evaluation of risk. We have the expertise and experience to identify the best approach for your site.

Imminent hazard evaluations are risk characterizations that:

  • Assess risk to human health and/or ecological risk over a short duration, and
  • Evaluate whether immediate actions are necessary to eliminate significant existing risk or exposure pathways.

 

Imminent hazard evaluations are not required at all sites, but are triggered by the presence of obvious conditions that could pose a risk to human health or sensitive ecological receptors over a short period of time.

Identifying cleanup levels allows us to develop clear, risk-based performance targets that provide you with measureable endpoints upon which to monitor the progress of remedial measures. Selection of the appropriate cleanup goals, whether site-specific or generic look-up values established by regulations, is vital when remediation is required or if the results of the baseline risk assessment indicate that certain site conditions pose an unacceptable risk. GeoInsight uses risk characterization to:

  • Define remedial objectives and identify practical solutions
  • Estimate remedial timelines and costs, and
  • Develop remedial goals that can be used to track and demonstrate when remedial actions are completed.

 We successfully conduct site-specific risk characterizations when generic clean-up standards:

  • Do not exist for constituents present
  • Are not applicable to the actual exposure present
  • Cannot be met within a reasonable period of time
  • Are financially unfeasible to achieve, and/or
  • When site conditions do not lend themselves to applying conservative assumptions.

 

Site-specific information (i.e., actual site use scenarios, contaminant distribution and accessibility, and surrounding human and ecological receptors) is used to evaluate and quantify risk compared to regulatory requirements.

Environmental risk characterizations are completed when exposure routes and areas of impacts are primarily associated with ecological receptors. The environmental risk characterization process is less standardized than human risk characterization, and is very site-specific. Consequently, developing a Conceptual Site Model (CSM) is a critical step in the environmental risk characterization process.

 

GeoInsight uses the CSM to evaluate the key, site-specific environmental receptors associated with your site. Identifying the key receptors drives the selection of the appropriate sampling and analysis approach. Because environmental risk is such a specialized area, GeoInsight commonly identifies and includes technical experts who have experience with assessing risk to site-specific flora and fauna.

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