11' x 10' Cast-In-Place & Brick- 112+ Year Old Interceptor - Baltimore, MD


1. Project Location: Baltimore, MD

2. Diameter of line, sewer pipe material (RCP, MCIP, brick, etc.), length of rehab portion: 11' x 10' Cast-In-Place w/ Brick, appox 333 LF

3. When was it constructed and how long has it been in service: Constructed in 1907/1908.  In Service 112 Years

4. Rehab method used: Danby Panel Lok III-E Panels used, bottom, curved corner and top panel, finished with full annulus grouting with cementitious grout with minimum compressive strength of 6,000 psi.

5. Cleaning method used (if required) and who cleaned the line: High pressure (8,000 psi) water blasting performed by Danby installer, Boyer, Inc.

6. Method of flow bypass or diversion, if used: A diversion was installed to divert the flow to parallel box interceptor.

7. Depth of pipe: Top of pipe at ground level.

8. Depth of ground water: 10'.

9. Ventilation and odor control used: 6'x6' exhaust opening was installed to install 5 HP Blower, 6' x 6' was later constructed into a manhole. 

10. Construction cost (total amount and cost per foot): $3,183,096

11. Month and year of start-up and end of construction: December 2018, completed July 2019.

12. Problems encountered during construction: Due to a crack in the crown, rehabilition was required prior to the General Contractors excavation and underpinning of Conduit as part of the construction of the newly rebuilt Back River WWTP. During cleaning, a crack along the floor revealed a cold joint which in turn lead to the discovery that the floor/walls were not a monolythic construction.  Additional reinforcement was engineered, approved and installed to support the floor during excavation and underpinning. 

13. Problems encountered after construction: None

14. Health and safety: Used conventional confined space entry program.

15. Has any re-inspection been performed? What was the condition of the pipe? WWTP construction is scheduled to be completed in 2021.

16. Special Awards: