What are EPA requirements for clearance sampling multifamily housing of 20 units or more?

What are EPA requirements for clearance sampling multifamily housing of 20 units or more?

• A. That a sufficient number of residential dwellings are selected for dust sampling to provide a 95 percent level of confidence that no more than 5% or 50 of the residential dwellings in the randomly sampled population exceed the appropriate clearance levels.
• B. Requires sampling exactly 20 % of units.
• C. Requires sampling only interior units.
• D. Requires sampling only exterior units.

Answer: (D)

Clearance sampling after lead abatement checks that the work area has been cleaned to the EPA’s dust-lead clearance levels. In a multifamily building with 20 or more units, the standard approach focuses on exterior surfaces because these areas are common to all units and can be a primary source of dust that migrates or recontaminates interior spaces. Sampling exterior units provides a practical, representative check of the exterior cleanup without needing to sample every interior unit, which would be intrusive and impractical in a large building. If work occurred inside a specific unit, interior sampling would be relevant for that unit, but the general requirement for large multifamily housing emphasizes exterior unit sampling to verify overall exterior cleanliness.

Clearance sampling after lead abatement checks that the work area has been cleaned to the EPA’s dust-lead clearance levels. In a multifamily building with 20 or more units, the standard approach focuses on exterior surfaces because these areas are common to all units and can be a primary source of dust that migrates or recontaminates interior spaces. Sampling exterior units provides a practical, representative check of the exterior cleanup without needing to sample every interior unit, which would be intrusive and impractical in a large building. If work occurred inside a specific unit, interior sampling would be relevant for that unit, but the general requirement for large multifamily housing emphasizes exterior unit sampling to verify overall exterior cleanliness.