Several environmental groups have sued the state and Boeing over what they allege is a “backroom deal” that significantly weakens the aerospace giant’s cleanup standards at the contaminated Santa Susana Field Lab site near Simi Valley. … In addition to Boeing and the toxic substances control department, the suit also names as defendants Lawrence Hafetz, the agency’s chief counsel, and the LA region of the California Regional Water Quality Control Board. The lawsuit also seeks to vacate a memorandum of understanding adopted in August by the water quality board that activists say could ultimately lead to Boeing’s surface water discharges from the site no longer being regulated.