Soil can be lead tested with two primary techniques: In-situ (on-site) screening and Ex-situ analysis (laboratory). In-situ testing is conducted using an XRF gun pointed directly at the soil. This provides for quick, real-time results and is fully compliant with US EPA Method 6200 for identifying contamination boundaries in the field. In-situ sampling is non destructive. However, in most lead testing scenarios, a small percentage of samples are collected for ex-situ sampling.
Ex-situ testing involves collected soil samples from the field and analyzing them off-site. In this technique, multiple soil samples are collected to provide a homogeneous array. While slower than in-situ testing, more accurate results can be obtained.