Improving climate resiliency through the development of a water quality trading program for recipients of national pollutant discharge elimination system general permits.

HB 1290 creates a water quality trading program for businesses and municipalities holding federal pollution permits (NPDES permits) that are not meeting temperature pollution limits in specific waterways. The bill requires Washington’s Department of Ecology to offer these permittees a market-based system to trade pollution reduction credits - such as by improving urban infrastructure - to meet compliance requirements. It specifically encourages projects addressing urban heat islands, like green spaces or reflective surfaces, as part of the trading incentives. This program directly affects entities subject to NPDES permits in watersheds with established temperature pollution limits. The law amends existing state water quality regulations to implement this trading mechanism, focusing on practical compliance solutions.