Water quality monitoring in the Northern Colorado Plateau Network, 2005–2007

Thoma, David; Malick, Matt; Moran, Mary

This report evaluates water quality monitoring data from 916 site visits made at 47 different locations on Northern Colorado Plateau Network (NCPN) streams and rivers in 8 NCPN park units between January 1, 2005 and July 31, 2007. Water-quality monitoring in Northern Colorado Plateau Network parks is made possible through partnerships between the National Park Service’s Inventory and Monitoring Program, individual park units, the U.S. Geological Survey, and the State of Utah’s Division of Water Quality. This report evaluates data from 916 site visits made at 47 different locations on NCPN streams and rivers in 8 NCPN park units between January 1, 2005 and July 31, 2007. Evaluation of water-quality parameters relative to state water-quality criteria indicated that 180 (19.7%) site visits exceeded state water-quality criteria for one or more parameters. While some exceedances were reoccurring and may have been caused by human activities in the watersheds, many were due to naturally occurring conditions characteristic of the geographic setting. The most common exceedances, in order of abundance, were due to elevated nutrients, low dissolved oxygen, elevated trace metals, elevated total dissolved solids, elevated temperature, elevated pH, and elevated bacteria (E. coli). In general, water-quality parameters fell within expected ranges for the sites relative to historical results. That is, sites that did not meet water-quality criteria still did not, and sites that did meet water-quality criteria continued to meet water-quality criteria. Water bodies whose natural conditions preclude their meeting assigned water-quality standards could be re-evaluated with respect to natural conditions and their assigned designated-use class.

Water quality monitoring in the Northern Colorado Plateau Network, 2005–2007

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