Del. Code tit. 20 § 3203
All political subdivisions and fire, rescue, and emergency medical service provider organizations within the State of Delaware are, upon enactment of this chapter automatically a part of the statewide mutual aid system. A political subdivision or fire, rescue or emergency medical service provider organization within the State of Delaware may elect not to participate or to later withdraw from the system upon enacting an appropriate resolution by its governing body declaring that it elects not to participate in the statewide mutual aid system; and providing a copy of the resolution to the Director of the Delaware Emergency Management Agency. This chapter does not preclude participating political subdivisions and fire, rescue and emergency medical service provider organizations from entering into supplementary agreements with another political subdivision or fire, rescue, or emergency medical service provider organizations and does not affect any other agreement to which a political subdivision or fire, rescue or emergency medical service provider organization may currently be a party to, or decide to be a part to.
20 Del. C. § 3203