Environmental Protection Agency (EPA) Lead Risk Assessor Practice Exam

What is the recommended number of units to sample in a multi-family building containing 25 units?

1. 30 units

2. 45 units

3. 60 units

4. 75 units

The correct answer is: 60 units

In the context of lead risk assessment in multi-family buildings, the recommended sampling strategy is based on established guidelines to ensure accurate representation of the potential lead hazards present. For a multi-family building with 25 units, it is critical to assess a sufficient number of units to obtain reliable data that reflects the overall condition of the property. The recommended number of units to sample is derived from statistical sampling principles, which aim to minimize the margin of error and enhance the validity of the results. Sampling too few units may not capture the variability of lead presence across the entire building, while sampling too many could be an unnecessary use of resources. Sampling 60 units effectively covers a broad cross-section of the building, providing insights into the lead risk that might be present in different locations and among various unit conditions. This larger sample size accommodates the potential for variations within the building population, ensuring that the assessment is comprehensive and reduces the likelihood of overlooking lead hazards that could pose health risks. Thus, the choice of sampling 60 units in a building with 25 units aligns with best practices for lead risk assessment, ensuring that the results are robust and that any necessary remediation strategies are effectively informed by the data collected.