Abstract: Session C 10:30 am (Back to Session C)
Effective Stream Restoration Construction Management within Piscataway Creek
Paul Le Bel, PE
Hazen and Sawyer
The Washington Suburban Sanitary Commission (WSSC) retained Hazen to design protection measures for two dozen exposed sanitary sewer assets within the Piscataway Creek Basin in Prince George’s County, Maryland, as part of its sewer repair, replacement and rehabilitation program. Hazen stream restoration designers developed Priority I-IV designs to restore stable channel form and function based on asset location, site constraints and erosion severity. Construction began in December of 2015 and was completed in 2019. During construction, Hazen designers worked closely with WSSC and its contractors to ensure protection measures met design intent. This presentation highlights several construction management topics deemed important to the owner (WSSC), the contractors, and the designers, including: (1) the determination of construction oversight budget and schedule; (2) the importance of designer presence during the first installation of any structure type (e.g., cross vane, j-hook); (3) communication and reporting mechanisms to provide both immediate/actionable feedback and record documentation; (4) the utility of scheduling tree removal site walks immediately after disturbance stakeout but prior to mobilization; (5) the development of efficient construction management habits; (6) satisfactory quality control of construction management reporting; and (7) the importance of flexibility to accommodate changes in existing conditions (such as new asset exposure, the complete loss of assets occurring between design and construction, unanticipated bedrock, and new stormwater pipe discharges). This presentation will touch on lessons learned throughout the construction phase of the project, as well as key analyses and design decisions which affected construction.