Does your foundry house a PCB risk?
As a result, more and more companies are turning to PCB experts for site assessment. Compliance with the EPA'S regulations for PCBS has become increasingly difficult. A foundry, for example, can house electrical transformers that vary greatly in age, condition and PCB concentration. With several options for PCB elimination available, you should not have to worry about choosing the best solution on your own.
Acting on PCBS
The EPA set an October 1, 1990 deadline for PCB transformers within 30 meters of commercial or public access buildings to be retrofilled, replaced or provided with enhanced electrical protection. Noncommercial transformers, those located in industrial buildings that are "directly used in manufacturing or technically productive enterprises," (EPA Final Fire Rule, 1985) were excluded. However, several factors present a strong case for the elimination of PCBS in noncommercial units.
The main incentive is risk management. Because of the potential hazards of PCBS, particularly those associated with the formation of toxic byproducts during a PCB fire, you run the risk of spending large amounts to clean up after a PCB incident. You not only have to be concerned with a PCB fire, but with leaks, spills and EPA inspections.
Recent insurance trends further add to the problem. Damages due to PCB transformer spills, leaks and other incidents are now often excluded from coverage in normal insurance policies. Contributing to this trend have been noted PCB accidents in Binghamton, New York, and San Francisco that have resulted in astronomical cleanup and litigation expenses.
The cost of keeping regulated PCB equipment in service also requires consideration. There are numerous restrictions placed on PCB transformers (those containing 500 ppm PCBS or more). Restrictions on use, disposal and servicing, as well as requirements for labelling, registration, notification, manifesting and record keeping make lawful elimination of PCBS a desirable alternative.
What may be the ideal solution for one transformer may no the for another. The transformer networks range in age, condition and other characteristics particularly in foundries where expansions over the years have resulted in the addition of various electrical systems. One facility's transformers may pose varying degrees of risk and may require more than one solution to eliminate the PCB problem.
The Electric Power Research Institute designed a model, used by utilities since 1985, to evaluate alternative solutions for PCB transformers and, based on the financial impact of each alternative, allow for the most cost-effective decision on how to proceed. Another approach to evaluating PCB transformer actions is the NASA Model, which bases a recommendation on risk to workers, equipment and the environment.
During a site assessment, trained technicians conduct an inspection of PCB equipment, as well as an evaluation of the options for PCB elimination and the costs of each option. Because not all transformers are alike, recommendations are made on a transformer-by-transformer basis.
An audit includes an evaluation of the following factors:
* type of transformer
* KvA of the transformer
* type of dielectric fluid
* number of gallons of dielectric fluid
* age of the transformer
* exterior condition of the transformer
* maintenance records, if available
* fluid analysis results. is the unit a non - PCB (less than 50 ppm), PCB-contaminated
50-499 ppm) or a PCB
* transformer (500 ppm or more)?
Risk Reduction Options
Essentially, you have three options. The first is to do nothing. However, a site assessment rarely recommends this option due to the inherent risks of a PCB incident and possible EPA regulatory issues associated with retaining PCB equipment. As a second option, you can replace or retrofit your PCB transformers. The old units can, lawfully, either be landfilled or destroyed through EPA-approved facilities. Retrofit eliminates the risks of PCB leaks and spills on site. Retrofit coupled with total destruction of the transformer at an EPA-permitted facility completes the elimination of the PCB equipment. Your third option is retrofill-replacing the PCB fluid with a non-PCB alternative. Retrofill minimizes PCB risks and is often the most cost-effective choice.
Given the options for PCB elimination, doing nothing is hardly a safe bet, and potential liability from landfill should also be avoided. To effectively manage the potential risk associated with PCB transformers, you should have your units retrofitted coupled with complete transformer destruction or retrofilled to non-PCB status.
Retrofill or Retrofit
Several factors weigh into the decision to retrofill or retrofit PCB transformers, reemphasizing how critical site assessment is before PCB decision making occurs.
Close attention is paid to the condition of a PCB transformer and associated electrical equipment to determine which option is best. If the unit is potentially faulty due to old age or corrosion, retrofit may be the only alternative. If there is no electrical reason for replacing your equipment (the existing equipment is well built, electrical needs will not be changing and the unit has sufficient remaining years of service), then retrofill is the more practical choice.
Cost obviously plays a role in the decision to retrofill or retrofit. In many cases, retrofill can result in a savings of up to 30% over the cost of replacement. A net present value analysis should be conducted to determine the best economic solution.
Transformer location is examined in two respects. A transformer's surrounding environment is evaluated to see how it has affected the unit's condition. Whether the surrounding location is clean, dirty or corrosive will weigh into the recommendation.
On the other hand, if a unit is in a hard-to-reach area-in a basement, surrounded by walls or other obstructions-then replacement may be extremely difficult, and retrofill will be the best option. Transformer location, however, should not be a key determinant. A transformer may be in such bad condition that it has to be replaced no matter how difficult the removal process.
Site assessment also takes into consideration whether a facility can accommodate power outages. In particular, a transformer retrofit project may result in downtime periods where temporary power is needed.
More on Retrofill
Retrofill offers immediate risk reduction because about 95% of the PCB fluid is removed from the transformer at the first servicing.
Two retrofill methods are currently on the market: off-site and on-site retrofill. Both methods involve an initial servicing where the bulk of the PCB fluid is drained from the unit and taken off-site for destruction. After the initial retrofill, however, the transformer still contains residual PCB fluid that must be leached from the unit's internal windings. Onsite and off-site processing differ in this respect.
During off-site processing, the PCB fluid is drained from the transformer and replaced with an interim fluid that leaches PCBS from the unit's core and coil. In most cases, three additional fluid changes follow over a period of about 18 to 24 months. The last fluid exchange is when the final non-PCB dielectric fluid, usually silicone, is added. After the mandatory 90-day in-service use period, in accordance with EPA rules, the transformer is tested and if found to contain less than 50 ppm, it can be reclassified to the EPA'S non-PCB status.
The on-site method utilizes a processor that remains attached to the transformer by a series of hoses after the initial drain of PCB fluid. The on-site processor continually circulates a PCB leaching fluid throughout the transformer to remove residual and absorbed PCBS. it separates PCBS from the leaching fluids and stores the concentrated PCBS in the processor. A final dielectric fluid can be added during a second and third servicing, and as with the offsite method, the unit must have a PCB concentration under 50 ppm after the mandatory 90-day period to be reclassified to non-pcb status.
The Retrofit Option
Even if your transformer is not faulty, retrofit may be the answer if your plant's electrical system needs have changed. Although costs are usually higher, transformer replacement can improve electrical system reliability, and it immediately addresses on-site PCB risks.
Although only one outage is required per transformer, it is important to note that many industrial transformers are of special design, and it can easily take several months to design, build and transport the new equipment.
During retrofit, the PCB fluid is drained from the transformer and transported to an Epa-approved incinerator for destruction. The old transformer is removed and replaced with a non-PCB unit. The new system is designed to meet your specifications and National Electric Code (NEC) and Occupational Safety and Health Administration (OSHA) compliance. The old transformer carcass can, lawfully, either be landfilled or destroyed.
Landfill disposal, however, is fast becoming an option most transformer owners want to avoid, particularly because of the potential for substantial financial risk. One of the risks of using a landfill stems from the amount of PCB fluid that can remain in a transformer-even after draining and flushing. The EPA recognizes that a drained and flushed transformer carcass can contain up to 100 lb of PCBS and that the fluid may eventually migrate into the environment.
The Comprehensive Environmental Responsibility Compensation and Liability Act (CERCLA) imposes joint and several liability for the costs of landfill cleanup. Under this premise, the EPA and the courts have consistently ruled that you can be liable for cleanup costs far beyond your transformers' contribution to the hazard.
The alternative-total transformer destruction-allows you to avoid landfill risk and to recycle valuable metal resources as well. First, the PCB fluid is drained from the transformer and transported to an EPA-approved incineration facility. The drained transformer is then transported to a permitted transformer destruction facility. The carcass is decontaminated, disassembled and separated into metallic and nonmetallic groups. Nonmetallic or combustible solids (such as paper and wood) are taken to an EPA-approved facility for incineration. Metallic components are cleaned and sent to a smelter for recycling.
You're Not Alone
Whether you have one transformer, 25 or 100, you may have a PCB problem that should be addressed. PCB elimination programs require careful consideration and planning, but with a site assessment program conducted by a qualified PCB services firm, you don't have to go it alone.
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|Title Annotation:||polychlorinated biphenyls|
|Date:||Oct 1, 1991|
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