Wastewater Pump Stations


Big Flat Creek Pump Station and Force Main

The Big Flat Creek Wastewater Pump Station is a 2.5 MGD regional pump station. Included in design was approximately 11,000 LF of force main and 16,000 LF of gravity sewer, as well as, the decommissioning of an existing pump station located within the basin.

This project involved evaluating the overall drainage basin for sewage demand and ultimate build-out feasibility based on the current zoning conditions. Once the pump station design criteria were established, ESI met with the Gwinnett County Department of Water Resources operations staff to determine specific needs to ease the demand of O&M and ensure the day to day operation of the station is efficient. This included determining the necessity of key components such as a 6-hour emergency storage tank, permanent diesel bypass pump with subgrade piping system, in-channel grinder in a composite grinder vault with bypass channel, carbon filter odor control system, and a chemical feed system. A key component identified in the overall efficiency of design was that the station would initially receive flows that are significantly less than full buildout conditions. Because of this, ESI carefully modeled the initial vs. build-out condition flows to select the best pumps, as well as, optimize the size of force main and other appurtenances.


North Chattahoochee Pump Station Upgrade and Interceptor Replacement – Gwinnett County, Georgia

The Gwinnett County Department of Water Resources (DWR) identified two potential problems with the wastewater infrastructure that feeds the Crooked Creek WRF.  The first concerned hydraulic bottlenecks within the existing gravity interceptor that flows to the North Chattahoochee pump station and the second was the capacity of the pump station itself.  The DWR selected ESI to perform an evaluation of the existing infrastructure (interceptor sewer, pump station, and force main) to determine the maximum capacity of each and identify the necessary improvements to increase the capacity to handle the anticipated future peak flows.  Once the improvements were identified, ESI was to prepare the necessary plans and specifications for construction.

ESI created a SewerCAD model of the existing system to identify the bottlenecks within the interceptor, determine the size required and provide options for making the improvements.  The pump station and force main were also analyzed to determine the peak flow that could be pumped through them to the Crooked Creek WRF.  The analysis of the system involved evaluation of hydraulics, transient analysis, air/vacuum valve sizing and locating, odor potential, pump selection, and pipe selection.  Additionally, an evaluation of the impacts of the increased pumping rate on the Crooked Creek WRF was performed.  Once the analysis was completed, ESI presented the findings, results and recommendations to the DWR.

Based on the results of the analysis ESI was asked to complete the design of the improvements to the interceptor consisting of replacement of approximately 7,500 LF of 30” and 36” RCP and PCCP with 48” DIP and other repairs to portions of the 48” sewer where negative grades were found.  Additionally, ESI was asked to prepare a business case evaluation of the best alternative for handling the projected peak flows at the pump station and Crooked Creek WRF. 


Possum Creek Pump Station and Force Main – Paulding County, Georgia

This project involved the installation of a new submersible wastewater pump station with two – 130 HP submersible pumps, new gravity sewer and a new force main.  The new force main connected to an existing force main from another pump station in the system.  Because of this, ESI performed a hydraulic analysis of the two pumping systems to determine how the pumps and force mains would perform under the different operating conditions (existing pump station in operation, new pump station in operation, and both pump stations in operation).

ESI was responsible for the planning, preliminary engineering, final design, and permitting of the pump station, gravity sewer and force main.  Construction of the project was managed by the Paulding County Water System. 


Scott Mill Creek Pump Station and Force Main – Canton, Georgia

New developments within the City of Canton’s wastewater service area required the extension of the wastewater collection and transmission system.  The City hired ESI to plan the necessary infrastructure to serve the Scott Mill Creek drainage basin.  As part of this project, ESI also prepared the plans and specifications for a new gravity sewer, pump station and force main.  The project included nearly 5,000 LF of 15-inch and 18-inch gravity sewer, a new 1,300 gpm submersible pump station, and parallel 8-inch and 12-inch force mains.  The dual force mains allowed the velocities to remain above 2.5 fps to minimize solids settling out in the force main during the initial low flow periods.  As the basin flows increase, the second force main will be placed in service to maintain the desired velocities and head conditions.  The sewer was installed along Scott Mill Creek and the Georgia Northeastern Railroad.

ESI was responsible for planning, preliminary engineering, design, permitting and construction management services for this project. 


Coppermine Lift Station, Force Main, and Sewer – Paulding County, Georgia

Paulding County needed to expand an existing lift station to provide additional capacity for planned development in the Coppermine drainage basin.  The County hired ESI to plan and design the required infrastructure to provide the required capacity.  This resulted in the design and construction of a new 1,600 gpm submersible pump station, 1,200 LF of 12-inch diameter gravity sewer, and 800 LF of 12-inch diameter force main.  The project also included the decommissioning and demolition of the existing pump station

The new force main was being connected to an existing force main from another pump station.  Because of this, ESI performed a hydraulic analysis of the two pumping systems to determine how the pumps and force mains would perform under the different operating conditions (existing pump station in operation, new pump station in operation, and both pump stations in operation).

ESI was responsible for the planning, preliminary engineering, final design, and permitting of the pump station, gravity sewer and force main.  ESI also provided construction administration and start-up services.


Pea Ridge Pump Station and Force Main and North Canton Sewer Interceptor – Canton, Georgia

This project involved the extension of the City’s wastewater system to provide wastewater service to the rapidly growing northern portion of the City.  The Pea Ridge pump station, with a 1,400 gpm capacity was installed to transfer the wastewater over the ridge and into the new North Canton Interceptor sewer.  The pump station included a new wet well, three submersible pumps, controls, and an emergency back-up power generator.  A new 1,400 LF, 12-inch diameter force main was also installed.

The interceptor included 6,300 LF of  24-inch, 4,600 LF of 18-inch and 1,500 LF of 15-inch diameter pipe.  The sewer was installed along a tributary to the Etowah River and through a commercial area of the City.  This required wetlands permitting and detailed coordination with existing utilities and infrastructure.

ESI was responsible for planning, preliminary engineering, design, permitting, construction management and startup assistance services for this project.