original_query: What are the consequences of paving large expanses of land in terms of pollutant runoff into streams and rivers? What is the most relevant chunk to answer the query?
query: What are the consequences of paving large expanses of land in terms of pollutant runoff into streams and rivers of the Puget Sound?
answer: Paving increases runoff of pollutants into streams and rivers, which then flow into Puget Sound.  This leads to high levels of toxins like PCBs in salmon, resulting in consumption advisories. Stormwater systems are overwhelmed, and stream flows increase during rainfall, causing erosion and harming salmon habitat.