Final answer:
According to the Department of Transportation (DOT) regulations, the emergency discharge valve on a tanker truck must be located no lower than 5 feet above the ground to ensure safety and accessibility.
Step-by-step explanation:
The emergency discharge valve, which is a component of tanker trucks used for transporting hazardous materials, must adhere to specific safety regulations. Among these regulations is the requirement for the emergency discharge valve to be located at a certain height above ground level to prevent accidental contact and to ensure ease of operation in an emergency. According to the Hazardous Materials Regulations specified by the Department of Transportation (DOT), the emergency discharge valve must be located no lower than 5 feet above the ground. This height ensures that the valve is both accessible to operators and protected from potential roadside hazards.