Methodologies for reporting emissions to water under the Industrial Emission Portal Regulation Final report. ETC HE Report 2025/9.

Unlike for emissions to air, there is no standardised method for quantifying emissions to water from intensive livestock production and aquaculture. In Europe, approaches vary depending on the country, activity and pollutant, and include mass balance, measurement etc. Surveys were conducted to identify current practices and if possible, propose a common methodology for livestock farming and aquaculture. For pig and poultry farms, no proposal is possible due to limited data and because the few methods mentioned are based exclusively on measurements. Conversely, for aquaculture, several countries apply similar mass balance methods, based on conversion ratios that characterise the fate of nutrients during fish rearing. Therefore, it is proposed that the three HELCOM / OSPAR formulas, which are applicable to all fish species, both land-based and sea-based facilities, and with flexibility for different data input levels, are retained.