Source Inventory

A source inventory is a quantified list of the discharges contributing a pollutant to a defined area, used to attribute loads and target reductions. Each entry pairs a source (river input, industrial outfall, shipping, atmospheric deposition, or diffuse runoff) with its estimated mass loading, supporting source apportionment and load allocation. OSPAR and HELCOM compile riverine and direct-discharge inventories for nutrients and hazardous substances to track regional reduction targets. The inventory is the data basis for setting load limits and judging whether a water body can meet a concentration or status objective.