ABSTRACT
Although regulations are being implemented at federal, state, and local levels, many major oil companies have decided to do even more than is required by law to prevent leaks from underground storage tanks (USTs). On the other hand, regulatory agencies directing cleanup of contaminated sites may demand restoration that goes beyond reasonable concerns for protection of public health and the environment. These cross-currents indicate that simply complying with applicable codes and regulations may not be an adequate strategy for cost-effectively reducing the risks of handling light refined products.
To control risks, it is important first to understand them. Risk assessment is useful before a leak occurs as well as after. Before the leak occurs, risk assessment requires estimates of the probability of release as well as the likely consequences (damages). Techniques are presented that can be useful to managers of a large number of tanks or insurance underwriters to assess risks and prioritize risk reduction measures. Ultimately, these procedures could be used to determine an appropriate budget for tank upgrade programs.
After a leak, and armed with detailed site assessment data, relatively precise estimates of toxic risks are possible. More realistic risk estimates are possible for refined petroleum product losses than are possible at many hazardous waste sites because of the relatively homogeneous and predictable properties of refined products. Field-verified predictive techniques that can be used to support defensible risk estimates are reviewed. Cost-effective strategies for collecting data required to support risk assessment and remediation of contaminated sites are stressed.
Risks can be mitigated to generally acceptable levels at some sites even if contamination substantially exceeds federal maximum contaminant levels (MCLs). At other sites, remediation to lower levels would be advisable.
Environmental risk assessment of transgene
products using honey bee (Apis mellifera) larvae
