The authors analyze runoff and road salt delivery and loading data from an indoor salt storage facility in eastern Massachusetts over multiple deicing seasons. The facility converted its delivery/loading from outdoors to indoors. Data and simple theory document a fivefold decrease in spillage as a result of the conversion. A seasonally varying balance of first order dissolution and a spill fraction is used to quantify the improvement; the data and model suggest that 0.3% of the outdoor delivered/loaded road salt spilled onto the pavement. The conversion to indoor delivery/loading reduced the spillage fraction to 0.06%.