Both nonpoint source pollution and point source pollution can impact water quality in streams, rivers, and lakes. Despite significant improvements to water quality from implementation of Clean Water Act regulations, many waters across the United States do not meet water quality standards. What is the most likely cause for the continued impairment of water quality?

Much of the pollution today is from pollutants being exposed to rainwater, and runoff is reaching the water.

The chemical industry is producing and discharging record amounts of chemicals into rivers and streams.

Environmental enforcement has been reduced, and more pollution is being discharged into rivers and streams.

Water quality standards have become more lenient, allowing more pollutants to be discharged into the water.