I am a California Civil Engineer and specialize in septic system design. My work generally consists of examining soil conditions and developing a septic system design based on these conditions. I have a subordinate (employee), who is an EIT but I think is irrelevant for the case at hand.
Very often my subordinate goes to a site and conducts the soil investigation, sometimes takes a soil sample for testing otherwise does in situ investigation of the conditions. Most often a county Environmental Health Department staff representative, who is very frequently a Registered we Environmental Health Specialists, is present to witness and sometimes log the soil also. One county is saying I need to be at the site as the “registered professional”. I am attempting to show the county that a subordinate can do the fieldwork under my direct control and they are not in a position to regulate the engineering laws.
Different but also similar seems like a land surveyor having other than licensed land surveyors doing fieldwork with the licensed land surveyor in responsible charge.
Does my concern make sense? Do you agree with my understanding on my presence not being required for a subordinate to do some of the project work and under my responsible charge control being proper?

Is it common practice for others to have fieldwork done by not licensed staff, but under the direction of a PE