BSA Fillmore Ave and Northland Ave Sewer Optimization

The BSA is optimizing flows conveyed to its sewage treatment plant by modifying overflow points to reduce the volume of untreated sewage discharged into the environment. The weir height and length was modified to convey more of the storm event flow to the treatment plant through construction of a new overflow chamber and a new outfall pipe to the receiving stream.

CHA evaluated locations to construct a new diversion chamber near the intersection of Northland Avenue with Fillmore Avenue and beneath a CSX railroad bridge. We coordinated with utilities to install formwork for the chamber wall without interrupting gas service. Since flows needed to be maintained to the BSA facility at all times, CHA selected a combination design for the chamber using cast-in-place walls, footers, weir slab and bench walls with precast pieces utilized for top slab and riser sections. Flow was maintained the entire time with only a couple minor pump outs of excavation directed to the sanity sewer and not the overflow.

A horizontal error in the old structure was uncovered when excavating to make the final connection of the outlet pipe to the storm relief sewer. CHA quickly adjusted the alignment and preserved safe tolerances to the CSX bridge without affecting the schedule.

Project Services:
  • Planning
  • Survey
  • Geotechnical Investigations
  • Internal Conditions Inspection
  • Review of Alternative Designs
  • Alternative Methods for Maintaining Flows During Construction
  • Design Drawings
  • Bid Documents
  • Traffic Detour and Maintenance and Protection of Traffic (M&PT) Plan
  • Permitting
  • Construction Estimates
  • Construction Administration and Coordination