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An Environmental Assessment of United States Drinking Water Watersheds
Citation:
WICKHAM, J. D., T. G. WADE, AND K. H. Riitters. An Environmental Assessment of United States Drinking Water Watersheds. LANDSCAPE ECOLOGY. Springer, New York, NY, 7(1):605-616, (2011).
Impact/Purpose:
Approximately two-thirds of the U.S. population relies on drinking water from surface sources (1, 2). The 1996 Amendments to the United States Safe Drinking Water Act (SDWA) (P.L. 104-182) shifted the emphasis of environmental assessment from contaminant detection to source water protection (3, 4). New in the 1996 Amendments was a requirement that each state develop source water assessment plans. Source water assessment plans include: 1) delineation of drinking water source areas (i.e., watersheds); 2) inventory of potential contaminants; 3) assessment of susceptibility of drinking water sources to contaminants, and; 4) public dissemination of the assessments. The shift to source water protection is a further development of the multiple barrier concept (5, 6, 7). The multiple barrier concept advocates using several defenses to protect drinking water. Source water protection adds conservation and protection of the land from which drinking water is drawn to treatment (filtration, disinfection), infrastructure investment (8, 9) and public outreach (3, 6). Source water protection is one element of a sustainable drinking water infrastructure (10).
Description:
There is an emerging recognition that natural lands and their conservation are important elements of a sustainable drinking water infrastructure. We conducted a national, watershed-level environmental assessment of drinking water watersheds using data on land cover, hydrography and conservation status. Approximately 78% of the conterminous United States lies within a drinking water watershed. The typical drinking water watershed had a high percentage of natural vegetation ( x~ = 77%) but a low percentage of it was set aside for conservation ( x~ = 3%). Median percentage values for urban and agriculture were 5% and 8%, respectively. Approximately 10% of the watersheds had at least a 1% increase in the amount of urban land between ca. 1992 and ca. 2001, and the majority of these urbanizing watersheds were located in the mid-Atlantic and Southeast regions.
URLs/Downloads:
WICHAM 10-096 EDITORS CHOICE..PDF (PDF, NA pp, 831 KB, about PDF)WICKHAM 10-096 FINAL JOURNAL ARTICLE JDWDWLANDECOL012111.PDF (PDF, NA pp, 346 KB, about PDF)