“Removal action work plan” means a work plan prepared or approved by the department or a regional board that is developed to carry out a removal action, in an effective manner, that is protective of the public health and safety and the environment. The removal action work plan shall include a detailed engineering plan for conducting the removal action, a description of the onsite contamination, the goals to be achieved by the removal action, and any alternative removal options that were considered and rejected and the basis for that rejection.