PCB REMEDIATION: MOOSE DECONS SITE TO OUTPERFORM SHOT BLASTING IN FINLAND
When a Finnish company needed to decommission the former ABB-Stromberg transformer manufacturing facility in Vaasa, Finland, it contracted Waste Management Finland, a wholly-owned subsidiary of Waste Management International (WMI), to remove concrete flooring contaminated with polychlorinated biphenyl. The project called for the dustless decontamination of 165,000 square feet (15,000 square meters) of floors and 11,000 square feet (1,000 square meters) of utility trenches. Criteria to release the facility for reuse required removal of the contamination to levels less than 1 microgram per 100 square centimeters and absolute control of the contaminated concrete waste. Since the adjoining property was part of an industrial park, exacting environmental control was demanded by the owner during remediation efforts. Project planners proposed scarifying the surface to the depth of clean, uncontaminated concrete as a direct, long-term remedy to ensure the eradication of the hazard without demolishing the floor. WMI decided to evaluate two remediation technologies: a traditional shot blasting machine and Pentek's MOOSE were both brought into the Vaasa facility for on-site demonstrations. "Although the shot blast machine initially showed potential in production, it could not go the distance with the depth criteria we required," said WMRS's Project Manager, Bruce Gordon. "Blasting was unable to do more than take off the top 1/32-inch (1 mm) of concrete due to dense aggregate layers, which left PCB-contaminated concrete still within the floor." The blasting system was also hampered by maintenance problems caused by the normal wearing of internal components, most notably the costly blast wheel, which required frequent and time-consuming maintenance. "Pentek's MOOSE floor scabblers, on the other hand, proved to be real work horses," Gordon continued. "They are an excellent system for the aggressive decontamination of concrete, while controlling any cross-contamination hazard." This comparison is supported by recent DOE findings positioning the productivity of Pentek's MOOSE scabbler at no less then twice that of blasting technology. 
The MOOSE produced a more uniformly keyed surface texture for subsequent industrial floor overlays to better adhere. Another key advantage of the MOOSE is its ability to reach within six inches of walls and columns. To address the inaccessible areas, WMRS acquired Pentek's VAC-PAC unit, SQUIRREL-III floor scabblers, and CORNER-CUTTER needle guns. This supplementary equipment was used also for the decontamination of 11,000 square feet (1,000 square meters) of utility trenches that traced the perimeters of the facility floors. "Due to the simple operating design of the equipment and the skillful Finnish labor provided by WMRS, it was easy to train the Finnish workmen despite the language barrier," explained John Sotiriou, Pentek's project manager. Two MOOSE scabblers were deployed to meet the time criteria, and they scabbled the facility to the required depth in 18-inch (45 cm) passes. The Pentek system surpassed expectations
and enabled completion of the project a full three weeks ahead of
schedule. "The dependability of the equipment was proven when twin
MOOSE operated continuously 24 hours per day, seven days per week,
other than pausing briefly for normal maintenance procedures," stated
John Sotiriou. After the Vaasa facility passed testing evaluations,
it was released for re-utilization by the community as a commercial
facility. |
