Abstract
This paper summarizes a basin-wide trends analysis of water quality data collected in the Clark Fork-Pend Oreille watershed from 1984-2004. The subject data were collected by the Montana Department of Environmental Quality (formerly MDHES) from 1984-1996 and by the Tri-State Water Quality Council from 1998 to the present. This study describes how nutrients, heavy metals and attached algae levels vary in time and space in the Clark Fork-Pend Oreille watershed. Nutrient constituents include total phosphorus, total nitrogen, soluble reactive phosphorus, and total soluble inorganic nitrogen. Heavy metal constituents include total recoverable fractions of copper and zinc. Attached algae biomass is reported as ash-free dry weight and chlorophyll a sampled from natural substrates.
Water quality was sampled at 32 stations along the Clark Fork River and tributary streams in Montana and Idaho, and at two stations on the Pend Oreille River in Washington. Seven Clark Fork River stations were sampled for algae.
Observed water quality is compared to standards and targets to determine the percent of samples meeting standards and targets. In addition, time trends are evaluated to determine whether or not water quality is changing significantly. Analysis results are used to gauge the effectiveness of management activities throughout the watershed, and to provide recommendations for future sampling efforts. A similar analysis is planned for 2008.
This work was funded by the Tri-State Water Quality Council.
Start Date
1-4-2005 3:00 PM
End Date
1-4-2005 3:30 PM
Document Type
Presentation
20 Years of Water Quality Status & Trends in the Clark Fork-Pend Oreille Watershed, 1984-2004
This paper summarizes a basin-wide trends analysis of water quality data collected in the Clark Fork-Pend Oreille watershed from 1984-2004. The subject data were collected by the Montana Department of Environmental Quality (formerly MDHES) from 1984-1996 and by the Tri-State Water Quality Council from 1998 to the present. This study describes how nutrients, heavy metals and attached algae levels vary in time and space in the Clark Fork-Pend Oreille watershed. Nutrient constituents include total phosphorus, total nitrogen, soluble reactive phosphorus, and total soluble inorganic nitrogen. Heavy metal constituents include total recoverable fractions of copper and zinc. Attached algae biomass is reported as ash-free dry weight and chlorophyll a sampled from natural substrates.
Water quality was sampled at 32 stations along the Clark Fork River and tributary streams in Montana and Idaho, and at two stations on the Pend Oreille River in Washington. Seven Clark Fork River stations were sampled for algae.
Observed water quality is compared to standards and targets to determine the percent of samples meeting standards and targets. In addition, time trends are evaluated to determine whether or not water quality is changing significantly. Analysis results are used to gauge the effectiveness of management activities throughout the watershed, and to provide recommendations for future sampling efforts. A similar analysis is planned for 2008.
This work was funded by the Tri-State Water Quality Council.