Thousands of sites in the United States and around the World are contaminated with petroleum hydrocarbons, volatile organic compounds, including chlorinated solvents and their breakdown products, and other substances. Unfortunately, the financial resources available to remediate these sites have been stretched to their limits. As a result, intrusive and expensive remediation projects can only be justified at sites with a present or impending risk to human health or the environment.
Many regulatory agencies have now issued more flexible cleanup standards which promote a risk-based approach to remediation. In 1995, the American Society for Testing and Materials released a Standard for Risk-Based Remediation that has gained acceptance, particularly among State agencies responsible for petroleum hydrocarbon spills. The success of the risk-based approach depends on many factors including careful site characterization, an evaluation of existing site characterization data, scientifically defensible evaluation of natural attenuation processes, and proper selection of effective low-cost remediation technologies.
The Air Force Center for Engineering and the Environment (AFCEE) estimates that implementing Monitored Natural Attenuation at over 50 sites has saved the American taxpayer more than $525 million in unwarranted and unnecessary remediation costs.
T.H. Wiedemeier & Associate’s approach to remediation is risk based. We believe that the decision to remediate a contaminated site and the degree of remediation required should be based on the present and predicted risk that chemicals pose to human health and the environment. This risk-based approach to remediation differs from the conventional assessment and remediation process by more efficiently integrating site investigation, risk analysis, and feasibility assessments into a single step. As a result, the entire assessment and remediation process focuses on how best to address actual, or perceived, site risks rather than becoming mired in an exhaustive analysis of how to return a site to an unrealistic “pristine” state. THWA is interested in assisting our clients in implementing this approach at contaminated sites.