How many people should be present above a manhole when an inspector or sampling technician is inside?

The presence of two people above a manhole when an inspector or sampling technician is inside is crucial for safety. This protocol ensures that there is adequate supervision and support in case of an emergency, such as if the technician encounters hazardous conditions or requires assistance. One person can help monitor the situation and alert authorities if something goes wrong, while the other can assist with any immediate needs or emergency measures.

Having just one person may not be sufficient for effective communication and assistance, while three or four could lead to overcrowding, which might complicate the situation or hinder emergency response efforts. Therefore, the standard practice of having two people on-site balances safety, communication, and effective emergency response.