Devices are provided for ventilating and/or removing volatile chemicals from liquid (e.g. water) stored in a liquid-containing storage tank (e.g. water-storage tank). The devices include a first fluid flow path that is physically isolated from a second fluid flow path and a convection device for moving a first fluid along the first fluid flow path toward at a desired destination and for exhausting the first fluid at the desired destination at a desired velocity. Methods are also provided for ventilating and/or removing volatile chemicals from liquid (e.g. water) stored in liquid-containing storage tanks (e.g. water-storage tanks). The methods involve blowing a first fluid through a ventilation device into a liquid-containing storage device at a velocity sufficient to achieve a desired mass transfer rate of volatile chemicals from the liquid in the liquid-containing storage device to air in the headspace and flowing the contaminated air back through the ventilation device.