ERC calculator petroleum and gas - Module 13 transcript

Watch the video Petroleum and gas ERC calculator training – Module 13 – Investigation contamination to learn about the Investigation and Contamination sheet and work through examples.

Welcome back to the training for the 2022 edition of the estimated rehabilitation cost calculator for petroleum and gas. This is Module 13. This module will work through entering data into the Investigation Contamination user input sheet.

The Investigation Contamination user input sheet allows the user to list out investigation areas and waste quantities for disposal off-site. The Main sheet has default rates for contaminated land investigations, including preliminary and detailed site or intrusive investigations, treatment of hydrocarbon impacted soil, and disposal off-site to a licensed facility. The default rates for activities in other domains including dams and ponds and process facilities include land investigation. Similarly, waste management including off-site disposal where required, is included in rates for those domains and activities such as wells.

Consequently, the rates in the Investigation Contamination user input sheet are unlikely to be commonly required. An example of where they may be used are a camp with an associated refuelling facility of material size, for example greater than a 5 kilolitre tank and associated pump or pumps. In this case, the sheet may be used to show the investigation. Another example is a separate land treatment facility where material volumes, for example greater than 500 cubic metres of soil, are being treated on a one-off or routine basis. Another example is a stockpile of metal or asbestos contaminated soil either on or off-site. Contaminated soil management is not included in the default rates. A further example is stockpiles of asbestos containing materials, for example from asbestos pipe.

The first table in the sheet is for site investigations. In general, an area will require one preliminary site investigation. The preliminary site investigation unit rate is a one-off cost. A preliminary site investigation in the context of a facility or site closure is typically a part of planning activities and aims to identify areas of known, suspected or reasonably probable contamination resulting from petroleum and gas operations. The preliminary site investigation comprises a review of the site settings, the site history, operational history including any incidents and accidents, hazardous liquids, solids storage schedules, and sources of potential impacts and the receptors.

If the user enters a preliminary site investigation but not subsequent intrusive site investigation quantities, the user should identify why in the user information column on the Main sheet or in the Information sheet.

The approach to estimating costs for site investigations recognises that most investigations of this nature comprise a single campaign, as in one mobilisation taking in multiple areas. The one-off cost allows for planning and preparation, ongoing project management, health and safety plans, work plans and reporting. A combination of the factors including risk, the nature and extent of the rehabilitation program, site history and grouping, and relative proximity of infrastructure must be considered in determining the number of one-off costs to apply. One example of an area that may individually comprise one campaign is a service facility area such as fuel or chemical stores, workshop, vehicle washdown, or sewage treatment. Another example is the oil storage at a processing plant.

The default rates for intrusive investigations assume several soil bores per area and a specific suite of analytes. The area is applied only to the area to be investigated. For example, for a tank farm within a processing facility, only the tank farm area is entered. The user can describe the area for a land investigation by entering width and length, diameter, or the area. This recognises that users will have different quantity types. Some users may use area outputs from GIS data and others may measure length and width off a plan. The hierarchy is user entered area, followed by width and length and then diameter. So if an area is entered, the calculator ignores any length and width and diameter entries. If area is not entered and length, width, and diameter are added, the calculator uses length and width and ignores diameter. The 'Calculated Area (ha)' column shows the calculation of area based on the user entered dimensions and if a value is entered directly to the 'User Area (ha)' column, the 'Area for calculations (ha)' column will default to that entry. If a group of investigation areas is entered to one row, the total area or sum of diameters or sum of widths and lengths must be entered so that all areas are captured.

The table summarises the quantities for preliminary investigations, one-off costs for site investigations, and the area of site investigations and reports these separately to section 12 of the Main sheet. These quantities are added to any entries made directly to the Main sheet and multiplied by the default rates to get the total for each line.

The next table is the disposal to off-site facility table. The user can select the contamination from the drop-down menu and enter the mass of that contaminant. Sludge can be used for tank bottoms or brine type material. Where applicable, the calculator will add the quantities entered to the off-site disposal table in the Waste Register and apply the levy. The columns to the right of the user entries show how the calculator has allocated the quantities and these are summed at the bottom of the table and reported separately to section 12 of the Main sheet, as for the investigation quantities.

Let's look at some examples. For investigations we will use the various different ways to enter dimensions. As always we first enter the map ID and then the name of the area. Let's call the areas Remote vehicle filling station, Legacy sludge pond area, and Remote landfarming area. For the first area, we have proof that a recent preliminary site investigation was undertaken so we will not enter a quantity. For the others a preliminary site investigation is required so we enter a one. The remote vehicle filling station is almost a perfect square and we have length and width measurements of 20 metres each. So we enter twenty to length and twenty to width. The legacy sludge pond area is almost a circle of a diameter 50 metres so we use the diameter. The remote landfarming area is an irregular area but we have a GIS generated polygon of two hectares.

For the disposal to off-site facility table, we again enter the map ID and name of the area. In each case we just enter the mass of the contaminated material to dispose and then select the contaminant from the drop-down menu. In some cases such as contaminated soil, a material may contain several contaminants. For the purpose of this calculator, the predominant contaminant is selected. Lets add 1 tonnes to each row to demonstrate how the quantities are reported to the right of the table and then through to the Main 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.

That concludes the final module in the training, thanks for joining me.

Watch the video: Module 13 – Investigation and contamination.