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Petroleum Storage Tank Management
Storage tanks: Whether above or below grade, storage tanks may pose both environmental compliance and contamination issues at a brown building property. Tanks no longer in use are typically closed before property transfer while those in use are evaluated for physical integrity and regulatory compliance. Planning for tank removal may require coordination with utility companies or facility managers. Closures may also require permits and other regulatory approvals. Proper planning can allow tank closure activities to be coordinated with other renovation activities for cost savings.
In addition to resolving environmental issues, brown building projects must also overcome problems common to any redevelopment project. These include coordination with multiple parties, uncertainty regarding actual project costs, and concerns about the time required for completion. A key factor in the successful resolution of these problems will be the overall planning and management of the project, beginning with the environmental investigation.
The Investigation: Prior to conducting the investigation, project goals, which will influence the nature and extent of sampling activities must be clearly identified. These goals may range from complying with specific lending institution requirements to developing information necessary for remedial action bid preparation. Past and future uses of the building must be incorporated into the sampling plan. Information on the physical features of the building should be inventoried to ensure that all potential environmental issues are identified. After project goals have been determined, comprehensive sampling and analysis plans can be developed, and technical issues, such as the types of contaminants, variability in the environment, collection methods, quality assurance objectives, and required confidence in the results should be addressed.
Interpreting the Data: Once the results of the sampling and analytical program become available, final decisions as to the disposition of material and equipment can be made. State or federal regulations often dictate acceptable residual levels of hazardous materials, but for most materials more complex risk management decisions must be made based on an analysis of the health risks, legal liabilities, and costs posed by each option. A site-specific risk assessment may be used to facilitate this analysis and to develop specific criteria representing an acceptable level of residual risk, taking into account the locations of hazardous materials, the intended future uses of the building, and the exposure scenarios anticipated by these uses. Site-specific criteria, which are customarily expressed in terms of the amount of a contaminant in a specific amount of building material or on a specific surface area, can then serve to delineate areas in need of remedial cleaning and to evaluate the effectiveness of the cleaning process.
The sampling program which is typically completed in two or more tiers focuses on critical issues; should it be designed to characterize the extent and intensity of the contamination? A detailed sampling and analytical plan is often prepared so that all parties can agree on the strategy in terms if its objective, methodologies, and quality assurance objectives.
Implementing Remedial Actions: A primary consideration in evaluating the need for remedial action in a brown building is the anticipated use of the property. Requirements for a building slated for demolition will differ considerably from those for a building slated for reuse as multi-family housing. Analysis of applicable federal, state, and local regulations must be conducted to ensure compliance with required remedial actions. Project goals can then be reevaluated to identify alternative, cost-effective redevelopment options, if necessary.
A variety of remedial solutions are usually available to re-commission a brown building. Where materials must be removed from surfaces, options include vacuuming, scraping, pressure washing, solvent washing, and absorption, depending on the material and the substrate. Materials that are to be managed in place may be covered with an encapsulant, or with a temporary or permanent barrier, such as concrete. The selection of the solution will depend on building features, the contaminants characterized, anticipated construction and occupant activities, the amount of material to be removed, technological limitations, costs, and timeliness. Sampling and analysis also can be used to evaluate contractor performance, to reduce potential time delays and excessive costs associated with ineffective methods. Post remedial sampling and analysis may also be required to confirm the effectiveness of the remedial action, and regulatory agencies may require that this information be submitted for review.
Conclusion
Because the re-commissioning of brown buildings requires the close coordination of several interested parties and disciplines, effective project management is essential. The successful project will control and document decisions, costs, and schedule commitments. The team of consultants, contractors, and laboratory analysts should be familiar with options for managing the risks that are likely to be encountered in the re-commissioning project and should have demonstrated experience in this area. Abandoned properties can be recovered without posing adverse risk to property owners or occupants. A sound investigation and resolution of site-specific issues will help overcome the hurdles of environmental compliance and risk management.