Water Resources Research Act Program

Details for Project ID 2009ND189B

Chemical Fingerprinting of Sediments and Water of the Souris River for Identification of Diffuse Pollution Sources II

Institute: North Dakota
Year Established: 2009 Start Date: 2009-03-01 End Date: 2011-02-28
Total Federal Funds: $20,000 Total Non-Federal Funds: $40,000

Principal Investigators: Marinus Otte

Abstract: Phosphorus is ubiquitous in water, soil and sediments. Excess phosphate in water can lead to eutrophication resulting in over-production of algae and other plants. This may lead to problems regarding water quality. Ecological problems include increased production of biomass of (potentially toxic) phytoplankton, decreased water transparency and depletion of dissolved oxygen. Social problems include the high cost of water treatment, loss of aesthetic quality of the river and reduction of fish species, many of which are economically-important. This project will focus on the environmentally and politically sensitive Souris River, which originates in Saskatchewan, then passes through North Dakota and Manitoba. There is international concern regarding phosphate loading in the water and the cross-border consequences of pollution transport. This river drains a large watershed including land that is used for cattle grazing. Cattle produce large quantities of phosphate in their waste which then washes into the river. However, the geographic origin of the phosphate is undetermined. Pinpointing the sources of polluted suspended sediments is critical for pollution abatement and regulation. In this project the potential for tracing sediments acting as phosphate sources to the Souris River will be assessed using the chemical fingerprinting technique. This involves determining the fingerprint concentration of many elements simultaneously. The technique provides quality and efficiency of analysis with the introduction of Inductively Coupled Plasma spectrophotometry (ICP). The elements considered pollutants can be analyzed quickly and at very low concentrations. Chemical fingerprinting has been used in plants and in tracing suspended sediment sources in catchments and river systems. In an earlier fieldwork it was recognized that the geology along this stretch of the river is relatively homogeneous and that the distance of river sampled was relatively short. This could mean that despite the observed variation in sediment composition it is not sufficient to provide identification over long distances. It is therefore proposed in this Phase II study that sampling in 2009 continue along another stretch of the river, between Minot and Bottineau. Along that stretch the geology changes from Cretaceous to Tertiary deposits and several large tributaries join the Souris River (e.g. Wintering River, Deep River and Stone Creek). More detailed sampling with more replicates (8-10) per site will be taken upstream from, downstream from, and in each of these major tributaries. The data will be analyzed using multivariate analysis and GIS-based modeling tools with the assistance of the GIS laboratory and the Statistical Consultancy Service of NDSU. Specific objectives are:

1. To obtain chemical fingerprints of sediments of the Souris River along the stretch of most geological variation, that is between Minot and Bottineau, particularly at the confluence of major tributaries, such as the Wintering River, Stone Creek, and Deep River.

2. To assess the concentration of phosphate in sediments and water at selected sites of the Souris River and identify potential sources of phosphate pollution.

3. To assess the spatial variation in element concentrations in water and sediments and relate them to the land use patterns and phosphorous loading in the Souris River.

4. To assess the biogeochemical behavior of elements in water and sediments of the selected areas of the Souris River.

5. To geographically model the variation of concentrations of elements along the Souris River.

6. To geographically model potential sediment and pollutant sources along the Souris River.