Table 5: General input parameters data entry

Situation

Select option button for Greenfields Site or a Brownfields Site.

Project commencement date

Enter full date (e.g. 1 January 2002 as 01/01/2002).

Operation commencement date

Enter full date (e.g. 1 January 2005 as 01/01/2005).

Commencement date of operation in new airspace

Calculated automatically.

Pre-development period/ assumed life of residual airspace

Calculated automatically.

Time of land purchase

Enter time (must be within the pre-development period).

Time of excess land sale

Enter time (must be within the operational life of the landfill).

Sunset date

Enter date, which will then display the consented life - the default is 35 years (under RMA maximum consent period).

Actual operating life

Calculated automatically, based on other input data (will not exceed consented life).

Aftercare period

Enter number of years (usually between 20 and 30 years).

Waste

Select option button for Custom Waste Tonnages or Generated Waste Tonnages. Selecting the Custom Waste Tonnages option will unhide the page tab titled Waste Input. Enter custom annual waste tonnage as tonnes/year (t/yr) or million tonnes/year (Mt/yr) using the same units used on the General Input sheet.

If the Generated Waste Tonnages option is selected, enter annual waste tonnage data and annual waste growth rate or reduction as outlined below.

Annual waste tonnage at start of operation

Enter as tonnes/year (t/yr) or million tonnes/year (Mt/yr)

Annual waste growth rate or reduction

Enter as +/- a fixed tonnage, or a percentage per annum.

Minimum allowable annual waste tonnage

Enter the minimum allowable tonnage for an operational landfill. (If for some reason the tonnage falls below this figure, the model will assume that the landfill closes on the date the tonnage reaches that figure.)

Waste stream characteristics

Enter percentage that is general refuse (e.g. if 100 % then the special waste proportion of the total waste stream will automatically display as 0 %).

Waste charging

Enter the relative disposal charges anticipated for various tiers of waste (i.e. the require % premium to be charged for special waste over the base charge).

Assumed compacted waste density (excluding cover)

Select from drop-down box (tonnes/m³).

Target cover (daily and intermediate) to waste ratio

Select from drop-down box (hence volume utilisation in metres³/tonne is automatically displayed)

Cost of capital

Enter percentage for each stage of the project (see section 5.4.21 of this document).

Interest rate

Enter rate at 0.5% higher than the 10-year Government Bond Rate.

IBC

Option buttons allow the user to selectbetween using IBC real annual movement or ramping the IBC from an initial (user entered) value to a final (unknown or goal seek) value over a set period of time. These options are outlined below.

IBC real annual movement

Select option button to apply real annual movement to IBC over whole operating life.

Enter as +/- percentage if required (i.e. if 0% then the IBC does not change over the life of the landfill - since inflation is not incorporated in the model).

Ramp IBC from initial (user entered) value to a final (unknown or goal seek) value over a set period of time

Select option button to ramp IBC from initial (known) value to a final (unknown) value over a set period.

Enter initial value (e.g. enter 30 for $30/t)

Enter year of operation from which to start ramping IBC (e.g. enter 2 for 2^nd year of operation)

Enter year of operation in which to finish ramping IBC (e.g. enter 20 for 20th year of operation).

Once the model has been solved, the IBC Chart will show the IBC on an annual basis over the model duration.