BP plc's stock dropped more than 10 percent yesterday, closing at $29.20, the lowest level in 14 years. BP shares have lost half their value since the April 20 drilling rig explosion in the Gulf of Mexico. Three beef feedlots in Iowa are facing civil enforcement actions from the Environmental Protection Agency as part of a continuing enforcement emphasis aimed at ending harmful discharges of pollutants from concentrated animal feeding operations into rivers and streams. Hastings-based Bruce Feedlot has agreed to pay a $31,573 civil penalty. Rock Valley-based Groeneweg Farm and Ireton-based Gradert/Cla-Don/Winterfeld Feedlot must apply for a permit and complete wastewater controls by Oct. 31. Initial jobless claims dropped by 3,000 to 456,000 for the week ended June 5, according to U.S. Labor Department figures released today.