All lead-based paint removal activities should include a containment plan for the purpose of preventing the dispersal of LBP residues into the environment. Effective containment of lead-based paint removal activities helps prevent exposure to lead from various routes. Inhalation exposure to lead in airborne dust may occur during removal operations. If the lead is not properly contained and thus deposited on the ground, inhalation exposure may also occur at a later time due to reentrainment of dust. Oral exposure to lead may occur when lead present on contaminated skin, clothes, food, or soil is transferred to the mouth and swallowed. Skin contact with lead is usually not a significant exposure concern due to the fact that inorganic lead is not readily absorbed through the skin.
A containment plan may need to address the following:
- ensuring that fugitive emissions to the air and deposition of lead onto soil or into water are minimized;
- providing for the collection of all waste streams generated (liquid, abrasive, dust, etc.) so that the handling and disposal of the waste is in strict compliance with environmental regulations;
- minimizing the risks to workers inside the containment by developing a design which displays the engineering controls and structural integrity necessary to minimize health risks and to maximize visibility;
- preventing public exposure to lead and deposition of lead particles onto public or private property;
- ensuring a design that can withstand episodes of high winds or can be lowered quickly in the event of high winds;
- considering the proximity of residential areas, schools, hospitals, or day care facilities;
- considering the proximity of wetland areas and surface water bodies; and
- considering the proximity of structures devoted to water supply or food processing activities.
The degree of containment and environmental controls needed will vary depending upon the site-specific conditions and the coating removal method that will be utilized. Dry abrasive blasting, although maybe the most effective paint removal method, is also the method which produces the greatest amount of dust and is the most difficult to contain. Water towers, due to their height and the increased air movement, present especially difficult containment challenges when conducting abrasive blasting. Whenever feasible, alternatives to dry abrasive blasting should be considered especially in residential areas or near school buildings and day care facilities where there is high potential for human exposure. Examples of some of the alternatives to dry abrasive blasting are such methods as vacuum blasting, hand tool cleaning, and cleaning with power tools with vacuum attachments. Methods which utilize high/low pressure washes or wet abrasive blasting decrease dust generation but present particular containment problems due to the requirement that all liquid waste must be contained and collected for proper disposal.
Environmental control measures, at a minimum, should include the use of impermeable groundcover. The groundcover should cover all bare soil and vegetated areas which may be impacted by removal activities. All surfaces should be thoroughly cleaned of all loose material daily and before the enclosure is moved.
Abrasive blasting should not be conducted when wind direction and velocity result in an ineffective containment; therefore, the containment plan should include a wind speed limitation that can be used to suspend operations.