For over 20 years EPA has been promoting water quality trading – with particular emphasis on nutrients and sediment – as a way to improve water quality at reduced costs. Trading is based on the simple proposition that if Party A can reduce a pollutant at a lower per-unit cost than Party B, who needs to reduce its discharges of that pollutant, it is more economically efficient for Party A to reduce its discharges below what is required by law, and sell the additional reduction, or “credit”, to Party B. If the price is less than what Party B would otherwise pay and more than it costs Part A to make the reduction, B will save money and A will make money.
