Pentek Power Tool Cleans Hazardous Lead from DOT-Bridge in N.J.

Abrasive blasting is the traditional technique used on such structures, but the full containment and ventilation systems required by abrasive blasting techniques substantially increase costs. Full containment would also disrupt the heavily-used highway, while tearing down the tarps in the morning and erecting them again each night would drastically impact on the hours available for deleading. For these reasons, the New Jersey Department of Transportation (NJ DOT) opted for an alternative process provided by Pentek, Inc., of Coraopolis, Penn., which eliminates expensive containment structures and maximizes the time for cleaning and repainting. Pentek's dustless lead abatement system was employed by CRX Environmental, a Pittsburgh-based deleading and painting contractor, to remove and collect the hazardous lead-based paint from steel I-beams and bearings, and concrete bridge abutments on the Route 495 pedestrian bridge near Union City, New Jersey.

NJ DOT project specifications made it clear that absolute control would be maintained over lead-contaminated dust and debris during the project. A NJ DOT project engineer was on site to verify that no discernible emissions were produced, an acceptable surface preparation was achieved, and new protective coatings were appropriately applied under acceptable environmental conditions.

Pentek's mobile VAC-PAC HEPA vacuum and waste collection system, stationed in the back of a standard pickup truck 100 ft. from the bridge, provided the capability to run up to 10 power tools simultaneously. Portable lights enabled CRX technicians to work through the night, eliminating daytime traffic interference. CRX's ability to quickly deploy and demobilize equipment and to flexibly configure the Pentek system increased the productivity of the abatement project while permitting almost normal traffic flow. The work schedule was drawn up by CRX and NJ DOT to specifically mitigate traffic problems: only one lane or entrance/exit ramp was closed during off hours and all lanes opened for morning and evening rush hour traffic. The Pentek system's capacity to operate without containment and ventilation structures also allowed more lanes to remain operable during deleading and repainting activities. Unusually heavy weekend traffic, returning late from the Jersey shore, prompted a request for rapid demobilization to free-up a lane of traffic--and the entire system, crew, and trucks were safely off the roadway in 15 minutes.

Tool operators in high lift trucks with 50 ft. reaches were situated on either side of the bridge. Workers attacked the I-beams with ROTO-PEEN Scalers and CORNER-CUTTER needle guns. The former evacuated power tool cleans flat steel to a bare metal finish, while the latter has interchangeable shrouds permitting access to tight corners, edges, and around bearings.

All coatings were removed by the 100 percent mechanical system and conveyed directly--via hoses up to 200 ft. in length--into a 55-gallon drum integral to the VAC-PAC unit, which seals the waste under negative pressure for a dustless changeout. After an area was deleaded, the crew immediately applied primer to protect the bare metal surface. The specified coating system consisted of two coats of aluminum epoxy mastic and a urethane finish. An epoxy waterproof seal coat was applied to the concrete abutments.

A previous demonstration for the NJ DOT of the cleanliness of Pentek's lead abatement system, buttressed by historical results, provided CRX technicians with the performance data necessary to forego burdensome respiratory gear. This increased productivity up to 50 percent per day in the hot, humid summer working conditions. Costs for OSHA-mandated health and safety requirements were likewise minimized. Post-project blood-lead level results for CRX workers averaged under 9 micrograms/dL, far below OSHA's regulatory limit of 40 micrograms/dL. Pentek's integrated removal system allowed CRX to finish the project well within schedule constraints. "The abatement system and repainting operation were excellent," said the principle bridge engineer for NJ DOT. Pentek's lead abatement system proved it is a viable, cost-effective alternative to abrasive blasting when erection of containment structures is cost prohibitive or logistically unfeasible.