What is a requirement for a septic tank in terms of structural integrity?

A septic tank must be watertight to ensure that it efficiently contains wastewater and prevents any leakage into the surrounding soil. This characteristic is crucial for maintaining the health of groundwater and minimizing environmental contamination. A watertight structure prevents the infiltration of groundwater into the tank, which could dilute the wastewater and hinder the separation process of solids and liquids within the tank. Moreover, it protects against the potential for pollutants escaping into the soil and water sources, which could pose health risks to humans and wildlife.

In contrast, while factors such as adequate design for accessibility and traffic support are important for practical purposes and maintenance, they do not address the fundamental requirement of avoiding groundwater contamination that watertight construction provides. Therefore, ensuring the septic tank is watertight is a key regulatory requirement and a primary concern in preventing environmental harm.