Systems and methods for removing volatile compounds from water-storage tanks

A system for reducing an amount of volatile organic compounds comprising:

• a water-storage tank comprising a tank containing water, a roof positioned over the tank, and a headspace region formed between the roof and a surface of the water contained in the tank;
• an air exchange system positioned at least partially in the headspace region that is configured to exchange air exterior to the tank with air inside the tank;
• and
• a water conveyance device located at least partially in the water of the water-storage tank and which is configured to convey water in a manner that produces a surface flow velocity,
• wherein the air exchange system comprises:
• (i) a port that enables air to flow out of the water-storage tank;
• and (ii) an active air ventilation device configured to facilitate movement of air exterior of the water-storage tank into the headspace region, and
• wherein the active air ventilation device is attached to the roof of the water-storage tank such that exterior air exits the active air ventilation device directly into the headspace region that is above the surface of the water.