Which items should appear on a groundwater monitoring well?

• A. A lock on the cover
• B. A label providing information on the construction of the well
• C. A label that reads 'groundwater monitoring well not suitable for drinking water'
• D. All of the above

Answer: (D)

Groundwater monitoring wells must be secured and clearly identified to prevent tampering, ensure safety, and avoid confusing them with drinking-water sources. A lock on the cover keeps the well protected from unauthorized access and sample contamination. A label with information on the construction of the well provides essential details for operation and future work, such as installation date, responsible party, and construction specifics. A label stating that the well is a groundwater monitoring well not suitable for drinking water communicates its purpose and helps prevent its use as a potable source. Taken together, these items ensure proper management, traceability, and safety of groundwater monitoring programs.