My firm replaces windows. Various obstacles make it difficult to set up the ten-foot exterior ground containment in a way that would enable our renovators to perform the work and still effectively contain dust. In these cases we lay the ground containment, but also use vertical containment measures to completely enclose the area in which we work. Is this a permissible method of exterior containment? If the vertical containment is set up at a distance of less than ten feet from the work surface, must we still extend the ground containment beyond the vertical barrier to meet the ten-foot requirement?
The work practices for exterior projects are based on a performance standard -- the work area must be contained so that dust or debris does not leave the work area while the renovation is being performed. EPA recognizes that proper use of exterior vertical containment measures may be a more effective method for containing the work area than use of the traditional ground containment alone, as outlined in the regulations.
With proper techniques, a firm may meet the performance standard by using vertical containment in conjunction with ground containment. Vertical containment means a vertical barrier consisting of plastic sheeting or other impermeable material over scaffolding or a rigid frame, or an equivalent system of containing the work area (40 CFR § 745.83). Properly constructed vertical containment, for example, might consist of a rigid box-like framework wrapped in impermeable plastic sheeting and anchored to the ground and home. When placed on top of ground containment, such containment should effectively limit the travel of dust and debris to the interior of the enclosure. Whatever construction techniques are used, the containment must completely isolate the work area and prevent any dust and debris from leaving the work area to satisfy the performance standard.
If exterior vertical containment is erected at a distance of less than ten feet from the work surface, the ground containment need not necessarily extend the full ten feet. Ground containment measures may stop at the edge of the vertical barrier when using a vertical containment system.