Question

The Verdex Code for Plumbers states that before beginning repair work on a sewage line in a house, the incoming water valve must be turned off. However, if the house uses a septic tank instead of city sewage, the Verdex Code is superseded by an older code (called the Stipex Code) that allows incoming water to be either off or on. In either case, the rule for turning incoming water off does not apply when working on commercial property. If the statements above are true, which of the following statements must also be true? A. The Verdex Code is widely observed by professional plumbers. B. Plumbers working on commercial property must turn the incoming water supply off. C. Plumbers must turn the incoming water supply off when working on houses with septic tanks. D. Incoming water is considered potable, whereas sewage water is nonpotable. E. The Stipex Code does not apply to houses connected to city sewage systems.

Short answer

The correct statement is E. The Stipex Code does not apply to houses connected to city sewage systems.

Step-by-step solution

Analyze the Verdex Code

According to the Verdex Code, before starting repair work on a sewage line in a house, the incoming water valve must be turned off. But this rule does not apply when working on commercial property.

Analyze the Stipex Code

If the house uses a septic tank instead of city sewage, the Verdex Code is replaced by the Stipex code that allows the incoming water to be either off or on.

Deduce the Correct Answer

Comparing the given options with the conclusions from Step 1 and Step 2. Option A makes an assumption about adoption rate which was not given in the original statement. Option B contradicts the Verdex Code rule for commercial property. Option C contradicts the Stipex Code rule for houses using septic tanks. Option D introduces new information that was not discussed in the original statement. Option E logically follows because the Stipex Code is specifically mentioned to be applicable for houses using septic tanks, implying it does not apply to houses connected to city sewage systems.