Water quality, sediment, and soil characteristics near Fargo-Moorhead urban areas as affected by major flooding of the Red River of the North.

Spring flooding of the Red River of the North (RR) is common, but little information exits on how these flood events affect water and overbank sediment quality within an urban area. With the threat of the spring 2009 flood in the RR predicted to be the largest in recorded history and the concerns about the flooding of farmsteads, outbuildings, garages, and basements, the objectives of this study, which focused on Fargo, ND, and Moorhead, MN, were to assess floodwater quality and to determine the quantity and quality of overbank sediment deposited after floodwaters recede and the quality of soil underlying sediment deposits. 17ß-Estradiol was detected in 9 of 24 water samples, with an average concentration of 0.61 ng L. Diesel-range organics were detected in 8 of 24 samples, with an average concentration of 80.0 µg L. The deposition of sediment across locations and transects ranged from 2 to 10 kg m, and the greatest mass deposition of chemicals was closest to the river channel. No gasoline-range organics were detected, but diesel-range organics were detected in 26 of the 27 overbank sediment samples (maximum concentration, 49.2 mg kg). All trace elements detected in the overbank sediments were within ranges for noncontaminated sites. Although flooding has economic, social, and environmental impacts, based on the results of this study, it does not appear that flooding in the RR in F-M led to decreased quality of water, sediment, or soil compared with normal river flows or resident soil.

Effects of liquid swine manure on dissipation of 17ß-estradiol in soil.

17ß-estradiol (E2), a natural estrogenic hormone, degrades within hours and bind strongly to soils and sediments; however, estrogens are frequently detected in the environment at concentrations that impact water quality. Colloidal (COC) and dissolved (DOC) organic carbon may enhance the persistence and mobility of E2. Soil batch experiments were used to identify the persistence and sorption of radiolabeled E2 dissolved in solutions of (i) COC/DOC derived from liquid swine manure and (ii) CaCl(2). Estradiol disappeared from the aqueous phase before 7 d in the CaCl(2) solution, yet persisted throughout the duration of the 14 d experiment in the liquid manure solution. There was also concomitant formation of estrone (E1; a metabolite of E2) as E2 dissipated in sterile batch experiments, which was attributed to abiotic oxidation. The liquid manure solution appeared to interact with the estrogen and/or oxidation reaction sites, reducing E2 degradation. Furthermore, the liquid manure solution reduced E2/E1 binding to the soil surface resulting in more E2/E1 in the aqueous layer compared to the CaCl(2) solution. Ultrafiltration results of liquid manure indicated that ∼1/3 of E2 was associated with COC, which may be responsible for the reduced degradation and sorption of E2 in the liquid manure solution.