DAKOTA CITY, Neb. (AP) _ Lawsuit replies filed by the owner of a biogas plant in northeast Nebraska blame two other companies for toxic odors that fouled a neighborhood. Reports say Denmark, Wisconsin-based Big Ox Energy filed the replies earlier this month in Dakota County District Court to more than a dozen lawsuits filed against the company. The neighbors who filed the lawsuits said odors and gases backed up into their homes, caused health issues and forced them to leave. Big Ox said in its replies that the blame lies with CHS Inc., a soybean processor that released acidic wastewater into South Sioux City’s sewer system, and Olsson, an Omaha-based engineering firm that Big Ox says recommended wastewater from the plant be routed through a sewer main that ran through residential areas. A CHS spokeswoman has declined to comment on the pending litigation.