Table 7.

Predicted annual percentage contribution (%) from septic tanks to the study area OP budget

Study area OP budgetSeptic tank OP loading contributions (%)
Septic tank discharge (unattenuated)PIT OP loading*Individual assessment (attenuated)
Loading (kg a−1)Source134.1 kg a−144.7 kg a−15.6 kg a−11.04 kg a−10.52 kg a−1
221OP loading leaving study area60.720.22.50.50.2
378OP loading leaving study area35.511.81.50.30.1
453PIT prediction (HOST Class 1)29.69.91.20.20.1
488PIT prediction (HOST Class 5)27.59.21.10.20.1
  • * In this assessment, OP has been extracted from PIT to make these quantities comparable with the other assessments presented in this table.