Page 66 - Highway Engineering Handbook Building and Rehabilitating the Infrastructure

ENVIRONMENTAL ISSUES 49

• Cost-effectiveness
• Compliance with applicable regulations
Materials used to construct containments include rigid panels or flexible materials such
as tarpaulins. The selected materials should be fire-retardant, given the sparking hazard,
high dust, and high ventilation aspects of the procedure.
The checklist provided in Table 1.16 may be followed in designing an appropriate con-
tainment system. Various debris-recovery assessment methods are underdevelopment.
Some, such as air monitoring and analysis of soil and water samples to evaluate whether

TABLE 1.16 Containment Design Checklist
1. Review drawings and specifications for project familiarity.
2. Investigate OSHA and EPA regulations affecting worker protection and control over emissions.
3. Determine method of surface preparation to be employed.
4. Examine the structure to be prepared:
• Confirm that the selected method of preparation is suitable.
• Determine if any coats of paint will be applied in containment.
• Assess the load-bearing capacity of the structure to support containment.
• Examine the structure for attachment points for the containment.
• Divide large structures into logical containment units according to size and configuration.
Consider the air movement requirements and the need to have a large enough area for pro-
ductive surface preparation and painting.
• Determine if a working platform should be used on elevated projects. Determine how far
ground covers should extend beneath or around the removal operation.
• When working over water, determine if a barge is going to be used for spent abrasive collec-
tion or staging, and assess the need for water booms to minimize problems due to inadvertent
spills. Determine the need for U.S. Coast Guard approval and navigation restrictions.
• Determine methods for conveying the debris for recycling or disposal.
5. Determine project-specific ventilation requirements.
• Consult Industrial Ventilation: A Manual of Recommended Practice (Committee on Industrial
Ventilation, American Conference of Government Industrial Hygienists, Cincinnati; 20th ed.,
1988) for engineering guidance.
• Select the air velocity (air speed) throughout the work area and exhaust volume required.
• Determine the necessary transport velocity through the exhaust ductwork required to avoid
dropout of debris.
• Lay out the ductwork as short as practical with as few bends as possible. Do not use bends
with a centerline radius less than 2 times the duct diameter. Include the use of exhaust hoods
or plenums within containment.
• Select the air-cleaning device (dust collector) on the basis of the volume of air and dust load-
ing of the airstream (air-to-cloth ratio).
• Select the fan that will provide an adequate volume of air, and that is able to overcome the
resistance throughout the system.
• Provide adequate makeup air (supply air), properly distributed to provide a uniform airflow.
Include properly balanced forced air if required.
• Confirm that all of the above will provide ample airflow throughout the work area. If not, con-
sider the use of localized ventilation and exhaust.
6. Obtain and review equipment manufacturers’ technical information.
7. Complete the design package. Utilize the expertise of structural and mechanical engineers,
industrial hygienists, coatings specialists, and equipment specialists.
Source: From K. A. Trimbler, Industrial Lead Paint Removal Handbook, 2d ed., Steel Structures Painting
Council/KTA-Tator, Inc., Pittsburgh, 1993, with permission.