Constantine Engineering, as part of the team upgrading the existing Calls Creek Water Pollution Control Plant (WPCP), provided stormwater design for the Design-Build project.  The project upgraded the existing unit processes and equipment at the WPCP.  As part of the project, the stormwater design included surface collection and stormwater management and treatment facilities for an approximately 4-acre expansion.  Pre- and post-development hydraulic modeling was performed to size the 0.35-acre stormwater detention pond per local and state regulations.  Hydraulic modeling was performed to size 300-linear feet of RCP surface collection piping and four inlets per local and state regulations.