Air-sampling methods will be used to detect CA during CWM responses. When soil contaminated with CA is encountered and an air concentration is at or above the STEL based on off-gas monitoring of the headspace of a container or of air in the immediate area of the operation, appropriate personnel protective measures shall be employed and the CA-contaminated soil shall be decontaminated to below the HWCL levels of subparagraph 15.4.6.4.2. unless the CA-contaminated soil may be shipped per DOT regulations and approvals and a receiving Treatment Storage Disposal Facility (TSDF) is qualified to process the CA-contaminated soil per Federal, State, interstate, and local laws and regulations. If air monitoring is below the STEL, soil samples will be taken to determine if the soil exceeds the HWCL.