The present disclosure includes a mobile liquid dispensing system adaptable to be implemented on an arm-bed truck. The disclosure includes an apparatus comprising a spray rig capable of engaging arms of an arm-bed truck, and a carrier operable to be hoisted by an arm-bed truck. A method of mobile liquid dispersion is also presented that be performed from an arm-bed truck. The disclosure offers many advantages in the art, including novel uses of an arm-bed truck and a spray rig that is resistant to damage from impacts.