Page 60 - Highway Engineering Handbook Building and Rehabilitating the Infrastructure

ENVIRONMENTAL ISSUES 43

Overcoating. This method consists of applying new layers of nonleaded paint over lead-
based paint with the intent of extending the coating system for another 5 years or so. This
method may reduce short-term costs and provide an agency more time while new innova-
tions in lead paint removal are being developed. However, worker safety and environmen-
tal issues still remain with the structure until the lead-based paint is removed. For
example, the volume of unleaded paint increases with each coat, and thus a greater quan-
tity of lead-contaminated paint must be disposed of as hazardous waste in many cases.
Additionally, performance of the overcoating products has been highly variable, depend-
ing on operator skill and experience, application conditions, existing paint that is being
overcoated, and product consistency.

Removal and Repainting. This strategy requires the use of abrasive blasting or other
means to remove the existing lead-based paint, followed by application of a coating system.
This would provide the most durable and effective protection for steel bridge structures.
However, its cost-effectiveness is diminished due to the need to collect and dispose of the
spent paint and blasting grit of as hazardous waste. Worker safety during removal is a sig-
nificant consideration.

Removing and Replacing Steel Members. This strategy involves removing members of
the bridge during major rehabilitation efforts; removal of the lead-based paint within an
enclosed workplace such as a fabricating shop; repainting, and restoring the members to
their original location. Containment of the lead paint and blasting grit is more easily
achieved with this approach. This method is generally cost-effective only on major reha-
bilitation projects.

1.5.4 Worker Protection during Removal of
Lead-Based Paint

Workers involved in removal, containment, and handling of lead-based paint must be pro-
tected against lead hazards. Blood poisoning has historically been a serious job hazard dur-
ing bridge painting and likewise dangerous during the removal of lead-based paint. In
addition, enclosing the work area to capture the blasting grit and waste paint creates a con-
fined area for the workers, increasing the potential level of exposure and health risk.
Guidance developed by the U.S. Occupational Safety and Health Administration
(OSHA) included in its publication Lead in Construction identifies proper health and safety
procedures to be observed by painting contractors. The procedures generally require train-
ing of employees, enclosure of the work area, decontamination of workers, the use of per-
sonal protection and monitoring equipment, and decontamination of personnel and
equipment when leaving the work space.
Unconfined removal of paint regardless of lead content presents environmental,
health, and safety concerns. It has the potential to result in unacceptable deposition of
dust and debris in roadways, streams, and communities, as well as presenting a hazard to
workers.

1.5.5 Removal Methods and Containment
K. A. Trimbler has described and compared methods of lead paint removal. His findings
are summarized in Table 1.15 and described below. (K. A. Trimbler, Industrial Lead Paint
Removal Handbook, 2d ed., Steel Structures Painting Council/KTA-Tator, Inc., Pittsburgh,
1993, and personal communication, August 2002.)