Final answer:
Water testing facilities handling moderate-risk agents are typically required to operate at biosafety level 2 (BSL-2), which includes additional precautions and safety measures.
Step-by-step explanation:
The biosafety level necessary for water testing facilities is determined by the potential risk of the infectious agents being tested. Laboratories handling agents that pose moderate risk to both laboratory workers and the community, and that are typically indigenous to the geographical area, should operate at a biosafety level 2, or BSL-2. This level of biocontainment includes additional precautions such as restricted access, personal protective equipment (PPE), the use of biological safety cabinets for aerosol-generating procedures, as well as having self-closing doors, eyewash stations, and autoclaves for sterilization.