Which class represents the long term soil acceptance rate of greater than 0.5 gallons per absorptive area per day?

The correct answer is Class 1a, which signifies a long-term soil acceptance rate greater than 0.5 gallons per absorptive area per day. This classification is important for determining the appropriate design and sizing of on-site sewage facilities. In general, higher acceptance rates indicate better soil permeability and the capacity to effectively absorb and treat effluent, which directly impacts the sustainability and effectiveness of an onsite sewage treatment system.

Understanding this classification system helps installers and engineers select the right type of system based on the soil characteristics of the site. This ensures that the system operates efficiently without causing environmental concerns, such as groundwater pollution or surface runoff of untreated sewage. The ratings are vital for making informed decisions about installation and maintenance for optimum performance and compliance with regulations.