Determine Baseline and Sources of Toxic Contaminant Loadings
USGS will conduct new water quality analyses for toxic substances in water and develop loads for streams tributary to the Great Lakes following the National Monitoring Network design.
U.S. Geological Survey (USGS) is identifying the types and locations of emerging and legacy toxic contaminants in the water and sediments at 59 major tributaries to the Great Lakes (including many Area of Concern sites). This information is needed by decision makers to help prioritize watersheds for restoration, develop strategies to reduce contaminants, and measure the success of those efforts in meeting restoration goals.
Scientific Progress for Restorative Action:
- Eight major tributaries of the Great Lakes have been sampled for 22 waterborne pathogens, human-specific fecal indicator bacteria, the USGS wastewater schedule, mercury, organic carbon, and optical properties of wastewater.
- Samples have been collected during periods of increased runoff due to rainfall low-flow periods (151 samples to date).
- Preliminary results indicate substantial human waste presence in all streams, but results have shown considerably higher concentrations of human-specific bacteria in five of the eight streams.
- At 5 of the 8 sites, colored dissolved organic matter (cDOM) sensors have been installed. CDOM sensors are designed specifically to measure dissolved organic matter. Data provided by the cDOM sensors will provide information on diurnal variability that will greatly enhance the understanding of biogeochemical cycling of these compounds in the Great Lakes tributaries.
Information on the occurrence and distribution of contaminants is needed to provide baseline information, measure progress towards restoration goals, and to assess new threats. Additional information is needed to provide an understanding of how contaminants reach the Great Lakes, and where they come from, so that the effects of future actions can be assessed and predicted.
The USGS will expand tributary monitoring according to the National Monitoring Network for Coastal Waters design. This project will include:
- Contaminant and virus monitoring using automated, passive, surrogate, and manual sampling;
- The development of watershed models throughout the Great Lakes.
The monitoring effort will help to make progress towards more complete implementation of the Great Lakes National Monitoring Network (NMN) for Coastal Waters tributary design and will include sampling in some embayments and drowned river mouths where tributaries discharge. This effort will be built on the ongoing USGS monitoring of these components and coordinated with proposals submitted to the EPA as part of the GLRI granting process.
The modeling effort is designed to create a model or set of models that can be used throughout the Great Lakes Basin to estimate flow, contaminant loads, and the effects of individual basins on the ecological well-being of the Great Lakes. The focus of this modeling effort would be to (1) provide a more detailed understanding of the hydrologic and water-quality processes in the basin at a scale not possible with a large-scale or non-process oriented model, and (2) identify sets of runoff and water-quality parameter values for the “representative” modeled basins that can be transferred to and used in basins with similar geological and hydrologic characteristics.
This information will provide baseline information, provide support for measuring restoration progress, and model potential load changes throughout the Great Lakes. This effort will be coordinated with the EPA, COE, FWS, States and other monitoring and modeling entities.