Submitted to: Society of Environmental Toxicology and Chemistry Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2003
Publication Date: 11/16/2003
Citation: Moore, M.T., Cooper, C.M., Smith Jr, S., Steinriede Jr, R.W., Farris, J.L., Stephens, W.W. 2003. Drainage ditch monitoring of the Delta Conservation Demonstration Center (DCDC), Mississippi, USA. Abstract Book of the 24th Annual Meeting of the Society Of Environmental Toxicology And Chemistry. p. 200.
Interpretive Summary: Abstract Only
Technical Abstract: Since April 2001, drainage ditches from the Delta Conservation Demonstration Center (DCDC) near Greenville, Mississippi, have been routinely monitored during both baseflow and storm events. The DCDC ditches are unique systems, capturing runoff from three major drainage sources: intensive agriculture, recreation (golf course), and industry (regional airport). Per season, between four and six baseflow collections and up to three storm flow collections have been analyzed. A suite of 17 water quality parameters were examined for each sample collection. Additionally, concentrations of pesticides were analyzed in two storm and three baseflow collections. Background concentrations of nutrients, metals, and historic-use pesticides were analyzed in ditch sediments collected in April 2001. Background 48 h aqueous toxicity assessments were conducted for each ditch site using Ceriodaphnia dubia. Surface water quality analyses indicated seasonal variations with slight differences in baseflow and storm events. No aqueous toxicity was observed with C. dubia exposed to background ditch water. Ditch sediment concentrations of iron (mean of 26,758 mg/kg) and aluminum (mean of 22,313 mg/kg) were of concern. With the exception of atrazine, for which concentrations were slightly elevated, residual concentrations of current use pesticides were present in trace amounts in both storm and baseflow collections. Atrazine concentrations were below the suggested ecological threshold of 20 ug/L. Continued monitoring of these drainage ditches, in addition to simulated exposures of pesticides, nutrients, and other pollution sources, will provide necessary information needed to realize the benefits of drainage ditches for mitigation of point and non-point source pollution.