Health, Safety, and Sanitation Requirements
Sanitation Principles
Plumbing protects public health by preventing contamination. Key concepts: cross-connection, backflow, backsiphonage, air gap, and flood level rim. Understand that potable water must be protected at every connection. Learn about sewage handling, ventilation of sewers, and the need to prevent sewer gas from entering buildings.
Safety on the Job
Know hazards: trenching and excavation, confined spaces, soldering fumes, and chemical exposure. Understand personal protective equipment, lockout/tagout, and safe handling of lead and asbestos in older systems. Learn about testing for leaks and the safe discharge of relief valves.
Traps in Questions
Distractors allow a direct connection between potable water and a drain, or ignore the flood level rim. Watch for questions on the minimum air gap and on which backflow device suits which hazard. Another trap: assuming a trap alone prevents sewer gas if the vent is blocked.
Worked Example
Rule of thumb: "Two times the effective opening." A minimum air gap is generally twice the diameter of the effective opening of the outlet, with a minimum dimension. Use this to test whether a proposed indirect waste is adequate.