Nearly 50 rural Delaware residents say they’ll sue a local Mountaire chicken-processing plant to force it to stop polluting their drinking water with nitrogen from chicken waste.

The threatened lawsuit targets Mountaire Corp. of Little Rock, Ark., and Mountaire Farms Inc. of Millsboro, Del., and involves the company’s poultry processing plant near Millsboro in Sussex County.

At issue is the plant’s wastewater treatment, storage, and spray irrigation on 928 acres of farmland near the plant. The plant has and continues to apply wastewater to 13 fields “in amounts that exceed agronomic rates,” according to the group’s notice of intent to sue, dated March 27 and sent to the company, the Environmental Protection Agency, and the Delaware Department of Natural Resources and Environmental Control.