viii, 76 pages : illustrations (some color), color maps ; 28 cm
General Note:
Shipping list no.: 2005-0044-P. "National Water-Quality Assessment Program."
Additional Physical Form:
Also available via Internet at the USGS web site. Address as of 01/07/05: http://water.usgs.gov/pubs/wri/wri034305/pdf/wri034305.pdf; current access available via PURL.