ERC calculator mining – Module 7 transcript

Watch the video Mining ERC calculator training – Module 7 – Infrastructure and process equipment to see examples of the infrastructure sheet and process equipment sheet.

Welcome back to the training for the 2022 edition of the Estimated Rehabilitation Cost Calculator for mining. This is Module 7. In this module we will work through examples for the Infrastructure sheet and Process Equipment sheet.

The Infrastructure sheet includes several tables to account for costs associated with disconnection of services and decommissioning of camps, buildings and ancillary infrastructure, and the restoration of disturbances associated with tracks and roads, lay down areas and borrow pits.

This sheet is the longest in the workbook and has a set of hyperlinks at the top to quickly access each table. The tables then have a hyperlink that will take the User back to the top of the sheet. Most of the tables are simple to use, with entered quantities multiplied by either the Default Rate or an Alternate Rate entered by the User with justification.

The first table is for disconnection of services, which includes electrical power, gas, water and communications. The table has an entry for major suppliers to a site and a second row for other remote areas of the site with dedicated services.

The next two tables are for tracks and roads. The first has Default Rates based on the length of a road with a default width and the second requires just the area disturbed by the track or road to be entered. The general principles throughout the calculator is that if a quantity is entered into one table, it does not then need to be entered into a second table. This is a good example of that concept in that the user does not have to enter quantities to both the by length and by area tables for the same disturbance.

The inclusion of two tables, one by length and one by area, recognizes that companies have data in different formats. Some maintain GIS systems that output area based polygons and others may have lengths measured in the field. For the by length tables, it is not expected that the roads and tracks have exactly the width mentioned, but should be close to. For example, if the average width of a track is five meters, the six meter wide selection should be used.

The next table allows the user to build their own road or track rate. As is typical for user build tables throughout the Calculator, the table starts with map ID and the name of the road or track. Groups of roads or tracks can be entered here, and if this is the case, the total length of all the roads must be entered. If a grouping is applied to a row, the road and track must have similar characteristics.

The first entry is the width of the road and a default is used if the user does not enter a width. The total length of the road or track or groups of roads and tracks is the key entry for this table. The next column allows the user to select the surface covering. The tracks and roads table in infrastructure have more options than those in exploration with default rates for tracks and roads covered with gravel, bitumen or waste rock, and for tracks and roads where the rock is removed with the assumption that it is contaminated and then replaced with clean rock to restore the road function.

The assumption with earthen tracks is that they only require ripping and revegetation if in pasture or native land. Earthen tracks in arid desert environments do not require growth media or seeding. For the purpose of the calculator gravel, rock and bitumen are treated in the same manner. The default assumption in this table is that surface covering is not replaced, however this can be set to 0 if the surface covering is to be replaced.

The next default is the thickness of the surface covering and the user can enter their own that will supersede the default. The volume of surface covering to remove is then calculated. The next section is used if the surface covering such as rock will be replaced. As an example, if a 10 kilometre gravel road will have the gravel removed because it is contaminated and then replaced with new, the user must enter 10 kilometres into this column.

The thickness of return rock uses a similar default method. The volume of rock to replace is calculated using either the defaults or the user entered values. For growth media and vegetation the default assumption is that the area is the total area of the road or track or group of roads or tracks, but the user can set this to 0 if, for example, the disturbance is in arid desert land.

The next section of the table works similar to all other tables in that the user can select the proportion of land that will be returned to pasture and native, or set both of those to 0 if the land is in the desert. If the total proportion of land allocated by the user does not equal 100%, an alert will be raised in this column.

The next section of the table is for fleet selection, with the first grouping being the distance to haul the material removed from the track or road, and the fleet size that will undertake the work. Keep in mind that anywhere there is a distant selection for fleet, it is for a one-way trip as the Calculator will calculate the return trip in the background. For example, if the distance to haul is 1.5 kilometres, the user would select the >1000 to <=1500 metre range.

The next fleet selection is for the distance that the surface cover material will be returned to recover the road, and the fleet size that will undertake the work. The final fleet selection is haulage of growth media, and the fleet size that will undertake that work. The selections of haulage distance and fleet sizes determine the unit rates in the next section and these rates are multiplied by the volume calculated in the earlier part of the table, to arrive at the total for each activity. The total of the activities are then summed to create a total for each row.

Above the table in this area are opportunities for the user to enter alternate rates for various activities if they can be justified. Justification for any alternate rates is entered into the justification for alternate rates column. The next table works similarly to the table just described, but the main input is the area of the road rather than the length and width. The next table is to account for costs associated with road and watercourse overpasses and is a simple enter the quantity approach.

The mine haul road set of tables works the same as the tracks and roads tables described previously, just with different assumptions. For example, a mine haul road is assumed to be much wider and have thicker surface covering than typical light vehicle access roads.

The lay down yard tables also work similarly to the tracks and roads tables. The first table is a default rate table where the user need only enter the area of the lay down or group of lay down areas, and the next table is a user build table which works similarly to the user build tables described previously.

The borrow pit table is a simple enter the area for each pit or group of pits in the different types of land. The next two tables are for pipelines not associated with plants and facilities. The general assumption is pipelines associated with processing facilities, for example, are included in those rates.

These pipeline tables are for pipelines that cannot reasonably be associated with a particular plant, for example, pipelines running from a pit to a processing plant. The user build table requires the length of pipe or group of pipes to be entered. The user then selects whether the pipe is to be flushed, whether each end will be cut and capped, and whether the pipe will be removed. The final part of the table is growth media and vegetation that works exactly the same as the other tables.

Two tables are available for camps. The first has default rates by size and type, that is temporary or permanent camp, and the second table by area. The by size category default rates include all the activities that can be reasonably associated with decommissioning and demolition of a camp and subsequent land rehabilitation. The camps do not include major refueling systems or land investigations, with the assumption that such activities are not always associated with camps. If these activities are associated with the camp, they must be entered separately.

The by area default rates for the camps account for typical infrastructure associated with the camp and an allowance for the vacant space between modules. Typically, it is reasonable to assume the land on which the camps sits is included in the rates.

The user will make the decision as to whether a camp is temporary or permanent, but typically any camp that is in use for more than two years should be considered permanent for the purposes of the ERC. The user can make a case for a camp being temporary if they can demonstrate things such as surface coverings are gravel or compressed earth with no concrete or bitumen and the absence of recreational facilities, such as tennis courts and gymnasiums.

For small mining operations and where camps are designed for a few people only, five or less, and comprised of simple infrastructure, the user can either enter alternate rates, use the small portable structures rate, or use the small temporary camp by area rate.

For a camp comprising of a caravan or one or two tents, one entry of the small portable structures rate may be sufficient. For larger but still simple and small camps, the small temporary camp by area rate is most likely more appropriate. The portable buildings table is for demountable type items, typically associated with temporary offices or crib rooms.

As with all default rates, transport of waste, scrap and reusable material is included in the rate and does not need to be added separately. Consistent with the ERC policy, the calculator does not offset the value of reusable material or scrap against the cost of demolition. The calculator does acknowledge that scrap steel will have a value and recognizes this in setting the gate fee to zero. Similarly, equipment and structures that will likely have a reuse are assumed to be stored at zero cost rather than demolished and disposed.

The remaining tables are simple to use and understand. Consistent with the approach taken throughout the calculator, tables such as concrete and bitumen do not need to account for costs associated with plants and infrastructure included in other tables. Rather, it is to capture any disturbance that is clearly separate to the other items. For example, airstrips are not included in the assumptions for any of the default rates and must be entered into the concrete hard stand table.

The approach to the calculation of a default rate for sewage treatment plants has changed for this revision, with the unit being the capacity in kiloliters per day of the plant. This accounts for the plant infrastructure and equipment and land rehabilitation. Consistent with the approach throughout the calculator, the fencing table is not designed to capture fencing around plants and facilities as those default rates include an allowance.

The small ancillary table is for discrete facilities separate to major plant facilities, or which cannot be reasonably assumed to be included in those facilities. For example, fuel filling stations are not included in the default rates for camps. Consequently, if a filling station is associated with a camp, it must be included in this table. Similarly, the tanks table is for discrete tanks that cannot reasonably be assumed to be included in other plants and facilities. As in other sheets, the subtotals for each table are summed and then those totals are added to the total for the sheet and then displayed in the summary sheet.

The process equipment sheet is simple to use in that quantities entered to each row are multiplied by either the default rate or the user entered alternative rate with justification. Consistent with the general approach in the calculator, the rates include all activities that can be reasonably expected to be associated with the particular item. For example, the dragline rates include dismantling and demolishing the machine and managing waste and reusable materials.

The sheet includes an optional table below the main costing table whereby the user can collate quantities. The intent is to clearly show where the quantities have come from, as the user can list that item in the table and assign quantities accordingly. These quantities are automatically populated into the cost table above and added to any additional entries made in the cost table. Consistent with the general concepts throughout the calculator, if entries are made into one table, in this case the quantities table below the cost table, they do not then need to be added to the cost table. Note there is one exception to this rule and that will be discussed in the ports sheet.

As in the other sheets, the totals for each row are added up and the overall total reported to the summary sheet.

As always, for more information or specific instructions, please consult the user guide which is also available on the Business Queensland website below the download for the calculator. See you in the next module.

Watch the video: Module 7 – Infrastructure and process equipment.