The function for calculating distributed acceptable load (kg/ha/year) from different areas within the recipient’s catchment area has been improved by reducing the load to be distributed in the area with reduced load within the catchment area (negative point load, Lpoint-). This does not give a change in catchment areas where a negative reduced load has not been calculated, but it gives a reduced distributed acceptable load and thus a higher required treatment load for areas where a negative point load has been added within the catchment area.