Under the Philadelphia Water Department’s Green Streets Initiative (GSI), NTM provided conceptual and final designs for the Cayuga Street green storm sewer system. The green storm sewer system will convey runoff to a subsurface infiltration system, designed by others, that will be constructed beneath the Ferko Playground in Juniata Park within the City’s northeast section.
NTM designed the proposed storm sewer system to capture the one-year storm per the City’s GSI standards. NTM developed hydraulic sizing calculations for the Cayuga Street GSI storm sewer system utilizing Bentley InRoads, which uses HEC-22 design criteria. The inlet and pipe sizes analyzed within InRoads are based on dimensions from 
Philadelphia Water Department standards. NTM carefully analyzed existing utility locations within the project area to ensure no conflicts with the proposed storm sewer system. Additional coordination with the Department was necessary to ensure that the proposed storm sewer system did not impact a proposed water main replacement project being constructed at the same time as the Cayuga Street/Ferko Playground GSI system.
NTM was also responsible for creating the storm sewer system plan and profile drawings in accordance with Department standards.