New disposal headache:
PCBs in lead-covered scrap cable

As if there weren't already enough problems disposing of lead-covered, scrap cable, many utilities have discovered that the oil impregnating the paper insulation is often contaminated with PCBs. The dual hazards of human exposure to lead, plus the widespread presence of PCBs is forcing companies to develop sophisticated testing and new maintenance and disposal practices. Outdated disposal methods now carry the dual liability of contamination of scrap yards (Fig 1) and exposure of workers to lead poisoning.	Unsealed ends of PILC cable have a great potential to contaminate the environment
Paper-insulated lead-covered (PILC) cable--widely used in urban underground network systems--is constructed of copper conductors wrapped with paper, impregnated with dielectric fluid. The cable is jacketed with a lead covering to keep out moisture, and may also have a plastic or rubber outer jacket. How the PCBs get into the oil is anybody's guess, but it could have migrated from PCB-filled transformers; other causes include improper maintenance, use of PCB-contaminated equipment in handling the oil, or even use of PCB oil in the manufacture of the cable. Upcoming changes to the Toxic Substance Control Act (TSCA), which are touted by the Clinton Administration as a streamlining of current PCB regulations, are anticipated to include provisions for the testing of all decommissioned PILC cable for PCB contamination.
Contamination may be uneven A major step in the reluctant acceptance of the widespread existence of PCBs in PILC cable is the understanding that, in most instances, PCB concentrations are not evenly distributed along a length of cable. Unlike transformer dielectric fluid, where PCB concentrations are evenly distributed within the closed confines of the tank, PCB concentrations are seldom homogeneous throughout a section of cable. This makes PCB contamination detection elusive. In many cases, a cable suspected of PCB contamination has been tested at both ends of a section and no contamination found. To determine conclusively if a section of PILC cable is contaminated, it must be tested in 30- to 50-ft increments. In some cases, significant levels of PCBs have been found evenly distributed along the cable. If this is the case, it can generally be assumed that the cable was contaminated at the manufacturing stage.
How to handle dual risks The issues associated with exposure of workers to both lead and PCBs, plus the possibility of site contamination by oil from the cables, has never before been fully considered. Regulatory guidelines for lead are very specific. Although no grinding or heating is necessary to process lead, the mere act of handling this \ material releases lead and lead oxide dust. Lead adversely affects numerous body systems and causes health impairment after a few days of exposure. Transportation of PILC cable on reels or in short lengths must now be on closed trailers with common spill containment. Processing of metal and non-recyclable material from PILC cable must be handled within a facility properly equipped to clean the metal and dispose of the PCBs. Contamination of copper wire presents additional unique problems and requires degreasing processes specifically permitted for cable containing PCBs. Cable oil is much thicker than transformer oil and must be cleaned with solvent permitted for cable. Aqueous processes, such as those used for cleaning transformer components, are not adequate for cable because they would not penetrate sufficiently between the tightly woven copper strands. Owners of underground PILC cable systems should consider a cable-testing program in anticipation of upcoming regulations. Generators of this material should undertake audits of all facilities that may have been used to process PILC cable in the past. Even when there are no detectable PCB levels, audits are recommended to ensure compliance with OSHA standards for lead exposure.
PILC processing center open TCI Inc. recently opened a special cable-processing center at Pell City, AL, one of its two centers for disposing of obsolete electrical equipment. All operations are conducted in a triple spill-containment building with a controlled environment. The center is operated under negative pressure, supported by a high-efficiency air-filtration system. The cable-processing sequence is shown in Figs 2 and 3. All workers use individual respiratory equipment, protective clothing, and eye wear. Regular medical screening, including monitoring of lead exposure, is conducted by a full-time industrial hygienist.
Cable is dereeled and cut into sections which are stripped of the lead jacket. The oil soaked paper is then removed from the copper conductor. (above) Copper conductors secrete oil even after the paper insulation is removed, showing the need for rigorous spill containment and proper degreasing. (right)

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