To limit the probability that:
- an inadequate drain pipe size will lead to frost-related
blockage, which could lead to flow restriction, which could lead to
- an inappropriate terminal connection will lead to unauthorized
disconnection, an inability to withstand repeated connection and disconnection,
or an inadequate seal, which could lead to leakage at the connection,
- inadequate protection from mechanical damage or frost-heave,
or soil-settlement-related damage, will lead to leakage,
- inappropriate termination will lead to system failure,
- the design or construction is inappropriate, which could
lead to system failure or leakage.
This is to limit the probability of
unsanitary conditions, which could lead to harm to persons.