Sewer or drain backups are one of the most challenging of all water losses. Any water that has come from beyond the toilet trap or a drain P trap is a category 3 loss, or “black water loss.” Some water overflowing from a toilet bowl may also be classified as a category 3. Category 3 water is considered grossly contaminated and can contain pathogenic, toxigenic, or other harmful agents.
It is obviously important that black water losses are handled correctly to ensure everyone’s health and safety.
