Abstract: An outlet conduit extends from an elevated water storage tank for discharging water into the tank of a tanker truck, which truck transports the water to a location of use, such as spraying the water at a construction site for dust control. A manually or remotely controlled valve actuator in a conduit extending from the storage tank controls the flow of water to the tanker truck. Power for operating the valve actuator is provided by batteries and solar panels to recharge the batteries. A remote control, actuated by a driver of the tanker truck, transmits radio frequency signals to the valve actuator to control opening and closing of the valve. A manual override accessible with a chain extending downwardly from the valve actuator may be used in the alternative to the remote control.