Corman Construction Tackles Lead-based Paint on

the Woodrow Wilson Bridge

Close to the Washington, DC headquarters of EPA and OSHA, a lead abatement project is proceeding on a public structure in a manner that is safe both to the environment and to the workers performing the deleading. Corman Construction, of Annapolis Junction, Maryland, is two-months into a lead-based paint removal project that is part of the rehabilitation of the Woodrow Wilson Bridge. The bridge, approximately 10 miles outside the nation’s regulatory capitol, crosses the Potomac River as part of Route 495, the Capitol Beltway, and Interstate 95.

Corman Construction was very careful in selecting a lead abatement technology for the Woodrow Wilson Bridge project. They looked for a methodology that would specifically eliminate the need for full containment structures--expensive requisites with traditional coatings removal techniques, such as abrasive blasting. These tent-like structures, along with associated air filtration and dust collection equipment, require lengthy set-up and can disrupt traffic flow on bridge projects. If the containment succeeds in protecting the environment, moreover, it substantially increases the potential exposure of the workers inside. Anyone familiar with the heavy traffic congestion on the Beltway also realizes that obstructive containment tenting or visible emissions of dust diffusing from the work-site would earn swift and negative attention.

The potential for escaped lead-contaminated air emissions during blasting operations also warrants the usage by abatement workers of full facepiece respirators operating in positive-pressure mode. Shrouded power tool technology has proven an effective engineering control that effectively prepares structural steel for new coatings, while simultaneously controlling all emissions in excess of 99.5%. In other words, the need for containment and respirators is eliminated or drastically reduced by preventing the potential for lead poisoning to the environment or workers in the first place.

Corman Construction chose to utilize Pentek's shrouded power tool system, which safely removes lead-based coatings and captures the hazardous airborne dust and debris at the cutting edge of vacuum-assisted power tools. These DOE, EPA, OSHA, and HUD-tested and approved tools utilize a mechanical, air-driven process that cleans surfaces to a bare substrate, while a High Efficiency Particulate Air (HEPA) filtered vacuum collection unit, the VAC-PAC, simultaneously captures dust and debris and transports it into an on-board 55-gallon drum. Only one shrouded power tool system offers a fully integrated deleading system that removes, collects, drums, and seals the waste in a single step process for safe disposal.

The Project
Corman Construction is employing the mechanical dust-free surface preparation system to delead numerous locations interspersed on the bridge’s superstructure. The company was contracted to remove lead-based paint and clean the surface in designated areas on the underside support structures of the bridge to prepare for new steel installation to augment the structure’s strength. Corman started on the Virginia side and is working eastward across the river to the Maryland side. A barge in the river is positioned and tied off below each new work area as the workers proceed. Two JLG 60-foot man-lifts support four abatement technicians to access the exposed steel of the support structures. Each elevated worker is tethered by Miller 851 safety harnesses.

The shrouded power tools allow the workers to prepare the structural steel to a bare metal finish comparable to a Steel Structures Painting Council SP 6 specification, Commercial Blast Cleaning. Pneumatic-powered rotary scalers and needle guns are being operated simultaneously--the former for the rapid deleading of large, flat surfaces and the latter with adjustable shrouds and pivoting head for access to hard-to-reach areas, such as around bolts and angles, or in corners. Fifty-foot vacuum hoses attached to the tools convey all removed dust and debris down to the HEPA-filtered vacuum and waste collection unit, which is stationed on the deck of the barge.

The lead-based paint dust and debris is collected in the vacuum collection system’s integral 55-gallon drum. Once a drum is filled, it is wheeled out for proper disposal, and, in a procedure taking less than two minutes, an empty drum is placed on the pallet and sealed under the unit’s pneumatically operated filter housing and exhaust head for continued operations. Corman Construction has filled one drum at the time of writing, and they expect to generate only one additional drum of waste during the remainder of the deleading project. Corman seals Tyvex coveralls and other disposables in the drums for disposal as hazardous waste also.

The 100% mechanical coatings removal system minimizes the amount of waste for disposal--and the degree of the owner’s liability and disposal costs--by adding nothing to the waste stream and collecting only the dust and debris of the coating itself. A typical lead abatement project employing Pentek’s system deposits 2,500 square feet of surface in a single waste drum. After each shift, Corman Construction uses the hose attachments with tools detached to clean the barge deck of the occasional loose, non-respirable chip, which the tools’ vibration and bridge traffic chanced to shake loose. Since containment structures are unnecessary and the collection system is stationed below the bridge, there are no disruptions whatsoever to the traffic above.

Air Monitoring
An independent company conducted air quality monitoring for the project with personal sampling and high volume environmental monitors, which were placed strategically at the site. Two separate air readings with the high volume environmental monitors were conducted six weeks apart, one on land and one on the barge. Corman Construction’s choice to complete the project with the dustless power tool system was justified when air sampling results came back at two to three micrograms per cubic meter, far below both OSHA’s Permissible Exposure Limit of 50 micrograms per cubic meter and the action level of 30 micrograms per cubic meter per eight-hour exposure limits. Corman Construction is protecting the surrounding air, water, and soil by utilizing a removal technology that captures all lead contamination at the point of removal. Most importantly, the built-in engineering controls are protecting the workers.

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