The aim of this project was to obtain an overview of how Swedish operators report releases to the environment based on values close to or below the reporting limit for the analytical methods used. Data was compiled in order to provide a background document that the Swedish EPA may use in their work to revise the Swedish guidance document on compiling environmental reports.

The data used in this study corresponds to 2016 releases reported by the facilities to the Swedish Portal for Environmental Reporting (SMP). The compilation was done for the recipients: Water; Air; Transfers of pollutants through wastewater (WWTP) and Wastewater treatment sludge (sludge – concentration). About 30 % of all values reported by the operators (both above and below the reporting limits) were connected to a comment on the reported value, but only some of these comments describe how the releases were calculated. The comments indicate that 0-values could refer to:

• the value was below the threshold value for the parameter,
• the concentration of the parameter in the measured sample was below the reporting limit for the chemical analysis,
• the parameter was not measured,
• the facility was not active during this specific year (no production).

If the facilities choose to use different ways to handle values below the reporting limit, the effects may be:

• large differences in release values for the same parameter and facility between years,
• large differences in releases between facilities within the same sector,
• some of the facilities may be identified as an outlier by the EEA Validation Tool at a national and/or international level.

This study also shows that there is no clear information on how to handle the emission calculations based on levels below the reporting limits and how to report those releases in the guideline documents linked to the different international requirements studied.