What volume of human waste is used per flush when calculating holding tank size?

The volume of human waste used per flush for calculating holding tank size is typically considered to be 0.14 gallons. This figure is derived from standard industry practices that take into account average usage and waste generation rates from marine sanitation devices.

Using 0.14 gallons in calculations ensures that the holding tank is adequately sized to handle the waste produced, accounting for both the waste itself and any flush water. This standardization is important for the effective and legal management of sewage in marine environments, where improper practices can lead to environmental contamination.

Other potential options would either underestimate or overestimate the necessary capacity, leading to either inefficient tank sizes or potential overflows, which can be problematic in real-world applications. Therefore, 0.14 gallons serves as the optimal benchmark for calculations related to holding tank size in marine systems.