When we're talking about entry-level field staff, some people tend to talk about the "techs", and I recently overheard a young geologist refer to himself as a "field technician". In consulting, field technicians and entry-level scientists are not the same thing, even though what they do in the field can look awfully similar. This is why I always refer to the samplers working under the supervision of a field manager as "field staff", because they can be either.
Generally, a technician does not need a four-year degree, has a clear list of regular, standard tasks, and does not make field decisions. A field tech is not considered a "professional" and therefore is not exempt from overtime rules. So many consulting firms claim that all of their junior staff are scientists who happen to also take regular samples/measurements. They really need to watch it, though, and make sure that those junior scientists are also working on more technically involved work and are in a position to make project decisions.
Technicians are not necessarily low level staff. I work with a CAD (computer aided design) technician whose pay is on a similar level to my own even though I have two more degrees and ten years more working experience than they do. While the CAD technician does some really cool stuff these days, the person who manages, reviews, and signs off on the drawings/renderings is a licensed professional scientist/engineer.
In my experience, field technicians (vs. scientists) are relatively rare in consulting. But this may vary by region/corner of the environmental business...