What types of streams did NAWQA sample?
NAWQA sampled both small (wadeable) and large (some wadeable and non-wadeable) streams and rivers to characterize the influence of nonpoint sources on the occurrence of nutrients in streams and rivers. Small streams (watershed area 50–1,000 km2) in specific, relatively homogeneous land-use (such as, agricultural or urban) and environmental settings were sampled to relate nutrient occurrence to individual types of nonpoint sources. In addition, streams with larger watersheds in areas of mixed land uses were sampled to evaluate the integrated effects of multiple sources of nutrients on their occurrence and concentrations.
