The plumbing code official must verify compliance with the standards through which of the following?

The verification of compliance with plumbing standards by a plumbing code official primarily relies on the inspection of the project site. This is because on-site inspections allow the official to directly assess whether the installation meets the required codes, regulations, and safety standards through visual examination and hands-on evaluation of the work completed.

Inspections can reveal issues that might not be documented or reported elsewhere, such as improper installation techniques, inadequate material usage, or adherence to design plans and specifications. Additionally, this process helps ensure that plumbing systems are safe for use and function as intended, conforming to both local codes and broader safety standards.

While documentation, reports from other officials, and peer approvals may provide additional context or support for compliance, they cannot replace the direct verification that occurs during an on-site inspection, which remains the most critical method for confirming that plumbing work adheres to established standards.