Consecutive days of deicing operations would have generated effluent volumes far in excess of the allowable discharge to the receiving wastewater treatment plant. However, the cost-benefit analysis demonstrated that it was feasible to recycle glycol at DIA provided the runoff came from a smaller ramp area, where the dilution would be less. Such a system would require separate collection lines, ponds and centralized deicing pads. Centralized deicing pads located near the ends of departure runways improve safety and operational efficiency in many cases. This configuration minimizes taxi time and therefore minimized the risk of exceeding holdover times.
Aircraft can leave gates as early as possible allowing arriving aircraft faster gate access.
Centralized pads ease ramp congestion caused by adding deicing equipment and personnel to the gate area, especially during storm conditions. They also reduce the number of identified areas near the departure runway threshold suitable for such pads. In addition, a fourth pad was built near the south side cargo apron. As a result, a supplemental system was built for United's Concourse B to allow them to deice at the gate more frequently. The effluent from the supplemental system is stored separately and can be pretreated for discharge to the on-site recycling plant or simply tucked away.