From March 1977 to July 1978 the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers conducted a series of elutriate studies to determine water quality in selected reaches of major navigable waterways of southern Louisiana. Samples were collected from the Mississippi River-Gulf Outlet area; Mississippi River, South Pass; Baptiste Collette Bayou; Tiger Pass area; Bayou Long; Bayou Barataria and Barataria Bay Waterway area; Barataria Bay Waterway area (gulf section); Bayou Segnette Waterway; Lake Pontchartrain near Tangipahoa River mouth; Bayou Grand Caillou; Bayou la Carpe at Houma; Houma Navigation Canal and Terrebonne Bay; Bayou Boeuf, Bayou Chene, and Bayou Black; Atchafalaya River channel, Atchafalaya Bay; Old River Lock tailbay; Red River below mouth of Black River; Freshwater Canal; Mermentau River and Lake Arthur; Mermentau River outlet; and Calcasieu Ship Channel. The studies were initiated at the request of the U.S. Army Corps of Engineers to evaluate possible environmental effects of proposed dredging activities in those waterways.
The U.S. Army Corps of Engineers and the U.S. Geological Survey collected 189 samples of native water and 172 samples of bottom (bed) material from 163 different sites. A total of 117 elutriates (mixtures of native water and bottom material) were prepared. The native water and elutriate samples were analyzed for selected metals, pesticides, nutrients, organics, and physical constituents. Particle-size determinations were made on bottom-material samples.
