title: U.S. Geological Survey perspective on water-quality monitoring and assessment.
authors: U.S. Geological Survey, 409 National Cetner, Reston, VA 20192, USA. rhirsch@usgs.gov
authors: Robert M
authors: RM
authors: Hirsch
authors: Pixie A
authors: PA
authors: Hamilton
authors: Timothy L
authors: TL
authors: Miller