In the fourth and final step, the mercury inventory is compiled using the results generated in steps 1 through 3. A standardized reporting template is given in the Toolkit as a separate document on UNEP's Tookit web page, ready to fill your information into. Using this template is recommended in order to ensure that all sources are considered (even if they cannot be quantified), data gaps are apparent and inventories are comparable and transparent. The presentation of inventory data is critical and should also be harmonized to allow for meaningful comparisons from one country to another.
In this section, guidance on what a full inventory report should present is given first, in order to give an understanding of the basic elements. Thereafter, suggestions for the preparation of interim reporting, which can be useful during the inventory work, is presented.
The guidance provided here is intended to assist in the assembly of reports that contain the crucial outputs from the inventory projects in formats that are immediately useful for the intended audiences.
4.5.1Key elements of the inventory
The full inventory report will identify the major activities and processes leading to mercury releases, in order to provide information on the nature and extent of processes linked to releases and to identify those processes for which there are important data gaps that should be addressed in the future. It will also address releases to air, water, and land, in products and residues, to the best extent possible while recognizing that there are significant deficiencies in the coverage and quality of data in some areas. Cases where no measured data or where no appropriate activity information (such as statistics) are available should be highlighted for follow-up, as financial resources become available.
The key elements that the inventory report should include are given below.
Summary:
The summary should include a brief description of the significant releases to all relevant media for the main source categories as identified in the screening matrix. This section should also include the estimated releases for important sub-categories (in a summary table or other appropriate format) as well as a short discussion of the principal findings. In addition, major data gaps, main release pathways and priority areas for data collection and improvements should be identified.
The completed country inventory:
Releases to all media calculated at the sub-category level. Numerical values are preferable; otherwise an indication should be given of the relative magnitude of releases (i.e. a ranking). Where no emission factors and no source specific measured data exist for the release quantification, this should be identified. Where no known release exists, this should also be identified. If a process/activity does not exist in a country, a phrase such as “This activity is not taking place in the country” should be introduced to show that the respective activity has been investigated, but was not present. Similarly, in an overview table showing all potential sources, sources not present can be marked with "NE", for "Not Existing in the country", or with similar clear marking.
Source category by category summary and analysis:
The bulk of a country report will consist of sections devoted to each of the categories investigated and detailed in the sub-categories. Each sub-section will provide information on the basic process, the approaches and means used to investigate potential releases from the process and provide the findings.
Each section is expected to be relatively short to reduce the overall report size. The key information will be included for each section. Use (consumption) information alone may in some cases be a sufficient basis upon which to initiate reduction activities for intentional uses such as mercury products.
Detailed supporting data:
In order to keep the inventory report short, this should not be included in the report itself. Larger data tables of clear relevance for the reader may be put in report appendices. Additional supporting data should be organized and held at the country level. It is important that the detailed background data is collected and maintained at the country level, to be available for review, further assessment and update at a later time.
Incomplete information:
Data gaps are common. Where information is incomplete, information obtained should be used to make an estimate for the activity. If information is insufficient to completely classify all processes, a range of potential relevant releases should be presented. If conservative assumptions result in very high estimates, further investigation may be needed.
The following example illustrates the point: Initial process information indicated all plants operated with pollution controls although the nature of the pollution controls was unclear. In such a case, it may be appropriate to take the range of emission factors from the sub-categories for plants fitted with pollution controls and exclude the emission factors for plants with no controls. This serves to narrow uncertainty in the inventory and helps to show need for additional resources.
Conclusions:
A short section summarizing the following points:
Principal sub-categories releasing mercury to each medium;
Results and evaluations of cross-check input/output mercury balances, if performed;
Measures in place to control these releases or expected changes to process/activities that will substantially alter the releases;
To supplement this Toolkit, a separate Excel spreadsheet is available electronically, intended to facilitate the calculation of inputs and outputs of the different source categories. Further information on this spreadsheet is provided in section 9.2 of this Toolkit.
Invite comments and review on the initial stages of the study before extensive resources are committed to the project;
Provide valuable initial comparative information at the national, regional and international level;
Show the potential size of releases from the significant sub-categories; and
Prioritize needs for further data gathering efforts.
The development of a mercury inventory on Inventory Level 1 of this Toolkit can be recommended, should an interim inventory be desired. Inventory Level 1 has simpler procedures and more standardised procedures, and can thus be finalised with less resources. Should Inventory Level 1 not be used and you still wish to perform an interim inventory, please observe the following recommendations.
The establishment of an interim inventory can take place after the main and sub-category sources present in country (or region) have been identified and the activity statistics have been generated (or other indications of their magnitude), but before completion of detailed information gathering exercises.
The interim inventory is designed to illustrate the potential size of releases from identified processes and thus, for early priority setting. For each source, the resulting output will be a very rough indicator of the size of the mercury releases.
An interim inventory might contain the following information:
Listing of all known sub-categories that are present in the country;
Summary tables of activity statistics for each sub-category, especially those sub-categories that are expected to be significant within the country, and to the extent this information can be obtained without extensive use of resources. Also, short remarks of how this information was found or estimated should be included;
Summary table showing the range of relevant default factors by sub-category, and the range of potential releases calculated with these default factors (activity rate multiplied by low and high-end input and distribution factors);
Illustration of the potential ranges of releases shown as a bar chart for each sub-category based on default emission factors.
The interim report would indicate the sub-categories that are likely to be significant sources of mercury uses and releases in the country, and those sub-categories for which additional information is needed, and can be used as a guide to where to place most effort in the next stages of the inventory compilation, as needed.
