Melt water can be discharged to either system, depending on the customer, and local regulations. The water leaving the snowmelter is usually cleaner than the snow entering the snowmelter. During the melting process, the heavy debris in the melting snow falls to the bottom of the melting tank where the debris will need to be cleaned out periodically and taken to the dump. Floating solids (larger than the discharge screening) would also be captured in the melting tank. Any snow contaminated with salt, oil, glycol etc would pass through the snowmelter. A catch basin with an oil and particulate interceptor to accept melt water would be prudent if oil contamination is an issue. Glycol contamination is not normally a problem except at airports. For example, Pearson International Airport’s Central De-Icing Facility directs all the melt water through their real-time glycol concentration monitoring system. Melt water with a glycol concentration over a regulated threshold is stored in large underground storage tanks for later reprocessing. Melt water below this threshold is discharged to the municipal sewer system.