Link to relevant standard
Does Environmental Sampling include sampling at water and wastewater plants?
TNI FINAL RESPONSE:
3.1 Environmental Sampling: Equivalent to "Field Sampling." See Clause 3.5.
3.2 Field: Any location outside the controlled environment of a laboratory.
3.5 Field Sampling: The process of obtaining a representative portion of an environmental matrix suitable for laboratory or field measurement or analysis.
In the definitions of the terms "Environmental Sampling" (3.1) and "Field Sampling", the operative term is "Field". In Clause 3.2 "Field" is defined as distinct from the "controlled" laboratory environment. It follows that the sampling sites for waste and drinking water treatment plants would be outside of a controlled environment so the answer to the question is "yes".
If the FSMO seeks accreditation to the TNI FSMO Volume 1 standard then the requirements in this standard apply.