Fellow: Adam Guy
Advisor: Thomas DeSutter, Ph.D., Assistant Professor, Department of Soil Science, North Dakota State University
Degree Progress: M.S. in Soil Science expected graduation in spring of 2010 

Surface flow from agricultural and urban areas may contain elevated concentrations of inorganic and organic chemicals compared to subsurface soil waters. The cities and adjacent lands in the floodplain along the Red River of the North (RR) were predicted to reach record flood levels in the spring of 2009. The flood was due to: 1) the extreme flatness of Red River’s gradient (ranging from 9 to 19 cm per km; 6 to 12 inches per mile); 2) during the fall of 2008 heavy rains saturated the soil, which reduces spring water storage and also forms a restricted frozen layer for infiltration; 3) record snowfall amounts in December of 2008 and a late blizzard (30 cm of snow, March 2009); and 4) the river flows north and ice dams to the north can exacerbate the flooding problem. Due to these conditions, the National Weather Service (Grand Forks) predicted a 50% chance of the RR reaching 11.6 m by mid-April (2009), or potentially much sooner. The flood was predicted to reach levels of 10.7 to 11.6 m above the river floor (35 to 38 ft), almost 2.5 m above the major flood level for Fargo. Therefore, the purpose of this study is to quantify the effects of agricultural and urban runoff from this extreme flood event on water and soil quality upstream and downstream of a major urban area of North Dakota (Cities of Fargo and West Fargo) and Minnesota (City of Moorhead), located along the banks of the RR. The urgency for this study was due to the immediate, rare, and short-lived opportunity for discovery. The RR water levels had only started to increase in depth and flow volume and the predicted maximum flood stage would be reached in mid-April, 2009. However, the flood came faster than expected and peaked around March 27-29 with a height of 12.4 m above the base of the river. The event was classified as a 500-year flood and the predicted hydrograph showing flooding was for only 50 days. We were unaware of any other study of this kind having ever been conducted in any city along the RR.

The RR originates in Breckenridge, MN – Wahpeton, ND and travels north through Fargo-Moorhead (F-M) before entering Canada and emptying into Lake Winnipeg. The major cities along the RR, from south to north, are Wahpeton, ND-Breckenridge, MN (pop. 13,000), F-M (pop. 150,000), Grand Forks, ND-East Grand Forks, MN (pop. 59,000), and Winnipeg, Manitoba (pop. 650,000). The RR is an important source of municipal water for these cities. The RR drainage area is estimated to be about 125,000 km2 (48,900 mi2). The soils of the drainage basin are mostly clay, silt-loam, and silty-clay remnants of glacial Lake Agassiz.

This research will investigate how location (upstream and downstream of F-M) and time before, during, and after the flood impacts the concentrations of diesel hydrocarbons, gasoline hydrocarbons, estrogenic hormones17β-estradiol (E2) and estrone (E1), total mercury, nitrate, ammonium, phosphate, pH, electrical conductivity, sulfate, chloride, and total suspended (in water) and deposited (on land) sediment. Diesel and gasoline hydrocarbons were reported to be a concern during the 1997 flood due to many garages, basements, and farmsteads being flooded and these chemicals were not controlled from being released into the environment. 17β-estradiol and estrone are hormones and are known endocrine disrupters, which have shown to be easily broken down in the soil environment. However, recent research by Casey has shown a much greater persistence in the environment than demonstrated in earlier laboratory studies. The source of these hormones can be animal manure, native wildlife, or discharge from municipal treatment plants. Total mercury in the environment can be from wet and dry deposition from atmospheric or local sources, native soil, or from urban sources. DeSutter has determined that the native soils of ND have a baseline total Hg concentration of about 31 μg g 1. Since the southern RR drainage basin is dominantly managed for crop and livestock production, specifically corn and soybeans, application of fertilizers is common. Since the RR drainage basin covers a large area (125,000 km2), the concentrated flow of the RR through the F-M area during the flood may have elevated concentrations of these chemicals compared to non-flooding conditions. In addition, urban runoff from lawns, roads, parking lots, rooftops, parks, flooded basements, and outdoor sheds may also influence the concentrations of all the chemicals listed above, specifically the fertilizers. Deposition of sediments having elevated concentrations of the inorganic and organic chemicals may significantly impact the greater than 420 ha (1,000 ac) of public lands in the F-M area, which include parks, cemeteries, golf courses, and community vegetable gardens.

Project Objectives:

The main objectives were:

1. determine if major flooding through an urban environment impacts water quality and
2. determine how major flooding impacts the quality of sediment deposited on the riverbanks after the flood waters recede.

Progress:

To date, the water and sediment/soil sampling is complete.  The analysis of the water quality is nearly complete, however, the data needs to be complied to run statistics.  The analysis of sediment/soil samples is still in progress.  To date, the study has analyzed sediment/soil samples for ammonium, nitrate, phosphate, sulfate, total mercury, total nitrogen and total carbon, cation exchange capacity, particle size, gasoline and diesel hydrocarbons, and 17ß-estradiol and estrone. 

Significance:

There are many benefits in knowing the water and sediment/soil quality before, during, and after the flood because of the land use near the RR. There are community vegetable gardens, city parks, cemeteries, golf courses, and residential lawns that are used for personal hobbies and activities. If the concentrations of chemicals, hormones, and/or nutrients were at levels of concern, this study will disclose any information that would help identify these levels. This study will help identify needs, if any, for land use changes and urban best management practices to reduce contaminations of water and sediment/soil to increase their quality, respectively.

Relevant Publications:

     Guy, A., T. DeSutter, F. Casey, J. Leitch, R. Kolka, N. Derby, H. Hakk, and K. Horsager. 2009. The impact of rural and urban flooding on water and soil quality in the Red River Valley of the North. ASA, CSSA, and SSSA Meeting November 2009, Pittsburgh, PA. (Poster). In Annual meeting abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.