A vehicle mounted system for applying and recovering de-icing chemicals from a surface , the system comprising: a spray system for applying a de-icing chemical to the surface ; a vacuum system for drawing the de-icing chemical and contaminants from the surface , the vacuum system conveying the de-icing chemical and the contaminants to a reservoir to form a combined solution; a recovery system for treating the combined solution, the recovery system comprising; a filter device for removing solids from the combined solution, at least one sensor for measuring a property of the combined solution, a source of de-icing chemicals, and a controller configured to: determine a property of the combined solution based on signals provided by the at least one sensor, move a supply valve to an open position to cause additive chemical to mix with the combined solution if the property is less than a predetermined minimum value, and move the supply valve to a closed position if the property is greater than the predetermined minimum value; and a sensing and monitoring system for measuring a presence and/or absence of contaminants and a condition of the surface before the de-icing chemical is applied by the spray system and after the vacuum system draws the de-icing chemical and contaminants from the surface . a spray system for applying a de-icing chemical to the surface ; a vacuum system for drawing the de-icing chemical and contaminants from the surface , the vacuum system conveying the de-icing chemical and the contaminants to a reservoir to form a combined solution; a recovery system for treating the combined solution, the recovery system comprising; a filter device for removing solids from the combined solution, at least one sensor for measuring a property of the combined solution, a source of de-icing chemicals, and a controller configured to: determine a property of the combined solution based on signals provided by the at least one sensor, move a supply valve to an open position to cause additive chemical to mix with the combined solution if the property is less than a predetermined minimum value, and move the supply valve to a closed position if the property is greater than the predetermined minimum value; and a filter device for removing solids from the combined solution, at least one sensor for measuring a property of the combined solution, a source of de-icing chemicals, and a controller configured to: determine a property of the combined solution based on signals provided by the at least one sensor, move a supply valve to an open position to cause additive chemical to mix with the combined solution if the property is less than a predetermined minimum value, and move the supply valve to a closed position if the property is greater than the predetermined minimum value; and determine a property of the combined solution based on signals provided by the at least one sensor, move a supply valve to an open position to cause additive chemical to mix with the combined solution if the property is less than a predetermined minimum value, and move the supply valve to a closed position if the property is greater than the predetermined minimum value; and a sensing and monitoring system for measuring a presence and/or absence of contaminants and a condition of the surface before the de-icing chemical is applied by the spray system and after the vacuum system draws the de-icing chemical and contaminants from the surface . <EOS>