The non-residential High Consumption Charge is calculated annually by repaying the Section 64 developer charges for water and sewer (presently $9,149 and $12,808 respectively) over 30 years with a discount rate equal to the 30-year Treasury bond rate (currently 3 per cent variable) and then divided by 205kL/y for water and 190kL/y for sewer. The figure of 205kL/y is the average annual water consumption per household (1 ET), and the 190kL/y is the average annual contribution to the sewerage system per household (1 ET).