Together, these areas account for 60 to 70 percent of the Nation's water use and population served by public water supplies, and cover about one-half of the land area of the Nation.
Water resources are of significant economic and ecological importance to the island.
Ground water provides essentially all municipal and domestic water for a large and expanding population, while streams provide important riparian and instream habitats for many threatened and endangered species. In addition, streams affect the physical, chemical, and aesthetic quality of receiving waters, such as estuaries, bays, and nearshore waters which are critical to the tourism-based economy of the island. The goal of this assessment is to characterize, in a nationally consistent manner, the broad-scale geographic and seasonal variations of water quality related to major contaminant sources and background conditions.